FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patent Rules, 2003
Complete Specification
(See section 10 and rule 13)
Sustainable Chemical Process For Reduction Of Nitro Compounds (R-N02) Or Nitroso Compounds (R-NO) Into Corresponding Amino Compounds (R-NH2) With Inherent Recycle Of All Liquid Streams Generated In Synthesis And By Separating Product By Steam Distillation.
Newreka GreenSynth Technologies Private Limited ; Rang Ashish, 2 Dreamland CHS, Opp Diamond Garden, Chembur, Mumbai 400 071, Maharashtra State, India ; Indian company registered under the Indian Companies Act, 1956.
Mr. Bhadresh K Padia; 1301, Emerald 11, Royal Palms, Aarey Colony, Goregaon (E) Mumbai 400 065, Maharashtra State, India ; An Indian National
Nitesh H Mehta; 620, Rock Enclave, Near Hindustan Naka, Charkop, Kandivali (W) Mumbai 400 067, Maharashtra State, India; An Indian National
The following specification particularly describes the invention and the manner in which it is to be performed.

Sustainable Chemical Process For Reduction Of Nitro Compounds (R-NO2) Or Nitroso Compounds (R-NO) Into Corresponding Amino Compounds (R-NH2) With Inherent Recycle Of All Liquid Streams Generated In Synthesis And By Separating Product By Steam Distillation.
Field of Invention:
This invention relates to a process for the reduction in general and in particular to reduction of nitro (R-NO2) or nitroso (R-NO) compounds into corresponding amino compounds R-NH2 with either reduction or separation or both reduction and separation of amines is by Steam Distillation and total recycle of all liquid streams generated.
Background of Invention:
Reduction, broadly defined as addition of hydrogen or removal of oxygen from any chemical, is one of the important chemical processes extensively applied in the manufacture of many molecules. Partial or complete reduction of functional groups such as nitro, nitroso, carbonyls, azides, nitriles, azo, and the like yields value added products.
Reduction of R-NO2/R-NO compounds into corresponding R-NH2 finds applications in various groups of chemical including pharmaceuticals, dyes and pigments, agrochemicals, specialty chemicals, fine chemicals and explosives.
Many dyes, specialty fine chemicals have R-NH2 as one of the building blocks and in most of the processes this important building block is obtained from the reduction of R-NO2/R-NO precursor. Some amino compounds like O-Anisidine, being currently used to manufacture various dyes and Pharmaceutical Intermediates.

Methods used for reduction of R-NO2 or R-NO into corresponding R-NH2 can be broadly divided into three major categories: (a) chemical reduction (b) catalytic reduction, (c) electrochemical reduction.
Skipka, G. et. al„ Ger. Offen. DE 2930754 (1981); Skalicky, P. et. al., Czech. CS 248864 Bl (1988), Laucoiner, M. et. al. in Appl. Catal., A, 172(1), 141-148 (1998) disclose methods of chemical reduction, which include metal and acid reduction such as Bechamp reduction, sulfide reduction, metal hydride reduction, hydrazine hydrate reduction and the like. Some of the drawbacks of these methods are that these processes require extreme pH conditions, handling of strong acids/strong alkalis, working in poisonous H2S / S02 atmosphere, handling of pyrophoric and/or explosive material, and expensive material of construction (MOC) for the equipment.
Another drawback is that these methods generate large quantities of liquid waste which is difficult to recycle. These methods require environmentally unsustainable reaction conditions in terms of pH, temperature, concentration, reaction agents and medium, and so on, and leave an unsustainable impact on the environment, specifically on our water bodies.
Shimanzu, K. et al. JP 9,132,536 (1997); Kuo, E. et. al. in Syn. Commun. 15(7), 599 (1985), disclose methods of catalytic reduction. The drawbacks of these methods, which normally use noble metal catalysts, are that they use highly inflammable hydrogen gas and require high pressure and/or high temperature. Further drawbacks of these methods are that they involve catalyst poisoning and regeneration, handling of pyrophoric catalysts, high cost due to use of pressure reactors and noble metal catalysts resulting in expensive, unsafe, and unsustainable, and inherently non-recyclable processes.

Gunawardena, N. E. et. ah, Acta. Chem. Scand., Ser. B, B37 (6), 549-53 (1983); Starke, C. et. al. in Chem. Tech. (Leipzig), 35(9), 463-5 (1983) describe electrochemical reduction methods. These methods suffer from drawbacks such as poor conversion rates and low yields, and that these methods require large quantum of electricity, rendering these methods uneconomical and environmentally unsustainable.
Pelster-Heinrich FR 1481040 (1967), Hu, Zhangyun from Ranliao Gongye (2002), 39(4), 32-34, Luo, Junlong from Faming Zhuanli Shenqing Gongkai Shuomingshu (2009), CN 101362710 A 20090211, Wang, Zaijun; Shi, Yan from Faming Zhuanli Shenqing Gongkai Shuomingshu (2009), CN 101337915 A 20090107, Sun, Chunbao; Lin, Hai; Wang, Zuosheng; Song, Bo from Faming Zhuanli Shenqing Gongkai Shuomingshu (2006), CN 1807269 A 20060726, By Wang, Yong-guang from Anquan Yu Huanjing Gongcheng (2006), 13(1), 70-72, 76, Rao, R. Nageswara; Venkateswarlu, N.; Khalid, Sara; Narsimha, R.; Sridhar, S. from Journal of Chromatography, A (2006), 1113(1-2), 20-31, Chai, Li-min; Zhang, Feng-bao; Zhang, Guo-liang from Desalination (2005), 180(1-3), 157-162, Horsch, Philip; Speck, Andreas; Frimmel, Fritz H. from Water Research (2003), 37(11), 2748-2756, Rao, R. Nageswara;Venkateswarlu, N. from Process Biochemistry (Amsterdam, Netherlands) (2006), 41(5), 1097-1105, describes effluent treatment generated during the synthesis using various chemical and/ or physical methods such as, electrolysis, chemical oxidation, reverse osmosis, vacuum distillation, ion exchange resin base separation and so forth. Inherently these methods describe effluent treatment method which is end of pipe solution and not the recycle of mother liquor.
Furthermore, other drawback of all methods described above is that undesirable organic and inorganic side products are always formed as a result of these methods. The type of side products formed and their quantities vary from process

to process and from molecule to molecule. This difficulty during recycle of mother liquor results in generation of large quantities of liquid effluents.
Yet another drawback of the methods referred to above is that in some cases inorganic solid wastes are also generated. These solid wastes are contaminated with organic compounds like starting material, product and side products and pose a serious pollution problem. Normally these wastes are sticky solids and are tedious to handle and are difficult to dispose off, and are known in the industry as non-green solid wastes.
There are still further drawbacks of the above methods. Because of generation of large quantities of liquid effluents and non-green solid wastes, above processes require a large facility for effluent treatment and disposal of solid wastes. These factors impose location related constraints making it mandatory for these processes to be carried out only in designated industrial areas, suitable for handling special chemicals.
Thus, these methods are non-green, unsustainable, uneconomical, and harm the environment to a very large extent, which has worldwide become a major concern.
Hence there is a need for providing a process of green reduction of R-NO2 or R-NO compounds into corresponding amino compounds (R-NH2) with inherent recycle of mother liquor, thereby avoiding above mentioned disadvantages and drawbacks, and providing an environmentally sustainable and economical recycling solution.
Objects and Advantages of Invention:
In order to overcome the various serious drawbacks of the existing methods, the inventors at 'Newreka Green Synth Technologies Pvt. Ltd.' have developed a

novel process using customized formulations such as G-Cat, R-Cat for the reduction of R-NO2 or R-NO into corresponding R-NH2.
An object of the process of the present invention is to provide isolation of amine in liquid form which has low boiling point by steam distillation resulting in avoidance of loss of product in vapour due to high extraction factor as well as time.
An object of the process of the present invention is to provide an environmentally friendly process that overcomes the problem of generation of large quantities of neutral waste resulting from the conventional processes of reduction.
Another object of the present invention is to provide a process, wherein undesirable side reactions leading to organic and inorganic side products formation are substantially reduced by the virtue of chemo-selectivity and regio-selectivity which results in purer product formation.
An advantage of the present invention is that since both the number and quantity of organic and inorganic impurities are comparatively less, the possibility of build of side products in neutral mother liquor during recycle is less due to use of the formulation G-Cat and R-Cat. This fact advantageously makes possible large number of neutral mother liquor recycles in our process.
A further advantage of the method of present invention is that the product separation processes disclosed herein ensure that the solid spent formed in the process of the present invention has surprisingly low levels of organic compounds and are thus green in nature. Consequently, the process described herein does not require any liquid effluent treatment facility or elaborate solid waste disposal facility. A further advantage of the process of the present invention over the prior

art is that the process is not constrained in respect of plant location, in that it doesn't necessarily have to be carried out in industrial areas.
A still further advantage of the present invention is that the inorganic by-product is non-sticky, which makes their handling easier and simpler than conventional processes.
Yet another advantage of the present invention is that the method disclosed herein not only is green and sustainable but the R-NH; produced by the process is also greener owing to the fact that they have fewer impurities. This makes downstream processing and application that involve this R-NH2 highly recyclable.
A yet further advantage of the present invention is that the method disclosed herein is carried out at milder reaction conditions and at atmospheric pressure, which makes it safer.
Another advantage of the present invention is that the use of the proprietary reaction formulations developed by the inventors, namely G-Cat and R-Cat, or any other similar formulations used in the process of this invention makes it possible to recycle the neutral process liquid streams completely.
A still further advantage of the process of the present invention is that its inherent thermodynamic conditions defined in terms of pressure, temperature, pH, concentrations of reaction components, and various reaction agents is close to respective conditions naturally occurring in the nature, thereby making the process of the invention benign and environmentally friendly.
There are several other key advantages of the process of the present invention. These relate to health and safety, process engineering, process economics. The process of the present invention is inherently safe due to the safe levels of the process parameters such as pressure, temperature, pH, concentrations of reaction

components, and various reaction agents. This reduces the risk of injuries to the personnel and damage to the process plant.
The simplicity of the process also makes its engineering design simple. One other key advantage is that the plant and process breakdowns that could take place due to factors such as power failure, or uncontrolled fluctuations in the process parameters, do not affect the recyclability of the process. This leads to reduction in wastage on account of batch failures. The process therefore is able to avoid sudden shocks to the environment and sudden safety shocks to the plant and the personnel, ultimately leading to sustainable health of plant and personnel.
The process is carried out at such temperatures and pH values that it saves energy and therefore results in the process economy.
Summary of the invention:
The process of the present invention creates sustainable and closed loop of water allowing inherent recycles of all liquid streams generated in the process.
Proprietary chemical agents are used in a novel manner which makes the process of the invention feasible, The liquid streams generated during the process of the invention are inherently recycled completely, making the process of the present invention a zero liquid discharge process which is green and sustainable.
This invention further relates to a sustainable chemical process of green reduction of R-NO2 or R-NO into corresponding R-NH2 that produces greener R-NH2 in good yields and selectivity with large number of recycle of mother liquor.
The process has a wide scope in that it can be applied to a number of molecules.
Brief Description of Figures:

Figure 1 shows a green reaction sequence with complete and large number of
recycles of mother liquor.
Figure 2 shows green separation sequence with complete and large number of
recycle mother liquor streams.
Figure 3 shows the schematic representation of complete process of the present
invention.
Figure 4 shows a simplified schematic relationship between individual cycles of
the large number recycle loop.
Figure 5 shows a schematic closed loop with large number of recycle of mother liquor in process of the invention.
Detailed description of the invention:
In order to aid the understanding of the process described herein several terms are explicitly defined.
• Reaction medium (RM) is the aqueous phase which is either acidic or alkaline or system with a miscible solvent or immiscible solvent, either high boiling or low boiling or a combination thereof used in the reaction.
• Fresh reaction medium (FRM) is the fresh aqueous phase which is either acidic or alkaline or system with a fresh miscible solvent, or fresh immiscible solvent, either high boiling or low boiling or a combination thereof used in the reaction.
• Solvent is any suitable solution that is water miscible or immiscible, either high boiling or low boiling, aromatic or aliphatic which is linear or branched, either substituted or unsubstituted or mixture thereof.
• Reaction medium factor (RMF) is the ratio of the weight of FRM or RM with weight of R-NO2 or R-NO used in the process.

• Mother liquor (ML) is the liquid stream generated after performing a particular step. Mother liquor has been used as the reaction medium (RM) at various stages of the process of the invention in its cycles following the first cycle.
• Nitro compound can be aromatic either mono or poly or aliphatic linear or branched, substituted or un-substituted where substitution can be alkyl, hydroxy], halogen, carboxylic acid, carbonyl, nitro, amino, amide, thio and all similar groups either mono substituted or poly substituted.
• Neutralization RM is the aqueous phase or system which is neutralized.
• Separation RM is the mixture of neutralized aqueous phase and immiscible solvent ready for phase separation.
• Settling RM is the mixture of neutralized aqueous phase and immiscible solvent which is settled for phase separation
• Cooling curve (CC) is profile of temperature verses time.
The process of the present invention uses a proprietary reduction agent, G-Cat, which is a multifunctional, chemical reduction formulation mainly comprising of fine iron powder in the range of 50% (w/w) to 100% (w/w), preferable range being 75% (w/w) to 95% (w/w), tin powder and or zinc powder in the range of 0% (w/w) to 10% (w/w). The purity of all components is in the range of 50% (w/w) to 100% (w/w). It also contains electrolyte salt of various metals such as sodium, magnesium, calcium, iron, nickel, cobalt, tin, zinc, titanium, copper, manganese, and any other metals with multiple valencies in the range of 0% (w/w) to 50% (w/w), preferable range being 2.5% (w/w) to 25% (w/w). The purity of the salts is variable and in the range of 50% (w/w) to 100% (w/w). The G-Cat also contains customized grade of activated carbon in the range of 0% (w/w) to 5% (w/w); filter aid in the range of 0% (w/w) to 95% (w/w) and decolorizing agent in the range of 0% (w/w) to 5% (w/w). It also contains specialty additives like polyelectrolyte, anti foaming agents, dispersing agents, anti oxidants, emulsifying agents, mass

transfer enhancing agents, anti caking agents, UV stabilizers, solubilising agents, and such other agents.
Other chemical formulation also used in the process of the present invention, namely R-Cat. This formulation is a multifunctional recycle formulation mainly comprising fine iron powder in the range of 0% (w/w) to 95% (wAv), tin, copper, titanium, and zinc, or any combination thereof, depending on the R-NO2 or R-NO to be reduced, in the range of 0% (w/w) to 10% (w/w). The purity of all components is in the range of 50% (w/w) to 100% (w/w).
G-Cat and R-Cat also contain electrolyte salt of various metals such as sodium, magnesium, calcium, iron, nickel, cobalt, tin, zinc, titanium, copper, manganese, and any other metals with multiple valences in the range of 0% (w/w) to 50% (w/w). The purity of the salts is variable and in the range of 50% (w/w) to 100% (w/w). The G-Cat also contains customized grade of activated carbon in the range of 0% (w/w) to 5% (w/w); filter aid in the range of 0% - 95% and decolorizing agent in the range of 0% (w/w) to 5% (w/w).
G-Cat and R-Cat also contain hydroxides of calcium or alkali metals like magnesium, barium, sodium, potassium in the range of 0% (w/w) to 95% (w/w); customized grade of activated carbon in the range of 0.5% (w/w) to 5% (w/w): filter aid in the range of 5% (w/w) to 95% (w/w) and decolorizing agent in the range of 0.5% (w/w) to 5% (w/w) along with iron powder in the range of 5% (w/w) to 25 % (w/w).
G-Cat and R-Cat also contain specialty additives like polyelectrolyte, anti foaming agents, dispersing agents, emulsifying agents, mass transfer enhancing agents, anti caking agents, UV stabilizers, solubilising agents, and anti oxidants, and other such agents.

The present application also discloses a sustainable chemical process for green reduction of R-N02 or R-NO into corresponding R-NH2 with inherent recycle of all neutral liquid streams generated in the same.
The chemical process of the present invention basically comprises inherent large number of recycles of processing the mother liquor streams generated during any of the cycles. Each cycle further comprises two sequences. The first sequence of typical cycle is represented in Figure 1 and is termed as the green reaction sequence. The second sequence is represented in Figure 2 and is termed as the green separation sequence.
The combined process involved in first and second sequences as disclosed in the present invention is shown in Figure 3. This figure shows the complete process of the present invention along with generation and fate of all liquid streams as disclosed in the present invention. One of the novel features of the process of present invention is regarding the reaction medium used in various stages of the process.
Figure 4 shows the relationship between individual cycles of the process.
Referring to Figure 3, In the very first cycle of the process, of the present invention FRM is used as the reaction medium in the start-up (Step 1.1) and reduction (Step 1.2) steps, and for steps involving washings (Steps 2.3, 2.4 and 2.6). As a key feature of the present invention, in the subsequent cycles, the liquid streams generated in various steps of recycling of the first cycle are used as the reaction medium. However, the use of these liquid streams as the reaction medium is optional and FRM can be used as the reaction medium in all cycles.
Streams generated at various stages of the invention are now defined. As shown in Figure 3, Stream A is generated after settling and decantation steps that follow the

reduction step. Stream B is generated after stirring, settling and decantation step.
Both these streams (Stream A and B) are taken for product separation by steam
distillation. Stream C is the mother liquor generated after the separation of R-NH2
from the reaction medium.
Stream C is stored in a storage tank. Stream D is the liquid taken from storage tank and which is used at various stages such as start-up, reduction and stirring, settling and decantation. Stream E is generated after stirring, settling and decantation. Stream F is generated after separation and washing of the inorganic by-product. Both these streams (Stream E and F) are taken to washings storage tank. Stream G from washings storage tank goes to stirring, settling and decantation steps. Stream H is generated from washings storage tank and goes to the mother liquor storage tank as make-up stream.
Some quantity of FRM or any other appropriate liquid streams, or a combination thereof are used as make-up liquid and or immiscible solvent either high boiling or low boiling in various steps to compensate for the various liquid losses through handling, evaporation, and so on.
Details of the steps involved in the two sequences that form a typical cycle of the process of the present invention are described below, with reference to figures 1. 2, 3, and 4.
The preferred embodiment of the present invention and various other embodiments are now described.
Sequence 1.0 - Green reaction sequence:
As shown in Figure 1, this sequence comprises four steps, namely the start-up, reduction, neutralization, and separation. Each of these steps is described below. One of the key features of this sequence is the various reaction agents that are used in various steps. These are the reducing agent and a neutralization agent. A

predetermined quantity of these agents is added as appropriate. These agents along with the specific reaction conditions generated as defined by the temperature, pressure, pH, agitation, and other such parameters lead to the unique inherent recyclability of the process of the present invention.
The total quantity of the reducing agent required in this sequence for a typical cycle (referred to hereafter as QRT) is dictated by the requirement of the reduction potential of R-NO2 or R-NO to be reduced. QRT is determined by a reducing agent's weight ratio, (Weight Ratio)RA, that is the ratio of the weight of the reducing agent required in a single cycle. WRA of the process of this invention to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle, WN. That is for a single cycle:
(Weight Ratio)RA = WRA/ WN Equation 1
The QRT is such that its weight is equal to WRA which is determined from Equation 1.
In the preferred embodiment of the present invention, (Weight Ratio)RA is preferably in the range of 0.25 to 25, the more preferable range being 0.5 to 2.5.
In the conventional processes, the power failures or other breakdowns of the plant lead to wastage of the entire batches leading to economical loss and environmental damage. One of the novel advantageous features of the process of this invention is that it allows recycling of the R-NH2 even without the stirring or agitation in many of its steps, particularly steps 1.2-1.4 and 2.2-2.5.
Step 1.1 - Start-up: This step is carried out in a reaction vessel that has an agitator and necessary attachments known to a person skilled in the art. As shown

in figure 1, at the start of the first cycle of process of the present invention an RM is charged to the reaction vessel in suitable quantities.
In the preferred embodiment of the present invention FRM is used as the reaction medium. The total quantity of the reaction medium required for a typical cycle (referred to hereafter QRMT) is dictated by the solubility of R-NH2. This quantity is determined by weight ratio of FRM or the reaction medium, denoted as (Weight Ratio)RM, that is the ratio of the weight of the FRM or the reaction medium required in a single cycle, WRM, to the weight of total amount of R-N02 or R-NO to be reduced in that single cycle, WN. That is
(Weight Ratio)RM = WRM/ WN Equation 2
The QRMT IS such that its weight is equal to WRM which is determined from Equation 2.
The quantity of the FRM or the reaction medium used in Step 1.1, denoted as QRM 1.1, is variable.
In the preferred embodiment, (Weight Ratio)RM is preferably in the range of 5 to 100, the more preferable range being 10 to 75, and QRM1.1 is in the range of 0% (w/w) to 40% (w/w) of QRMT used in this cycle.
Optionally, a suitable acid, or a salt of iron with inorganic or organic acids, such as ferrous sulphate, ferrous chloride, ferrous ammonium sulphate, ferrous oxalate, ferrous citrate or other salts like ammonium chloride, ammonium sulphate, other such salts, or any combination of these, is added in suitable quantity and suitable form while maintaining temperature of the reaction mixture in the reaction vessel in the range of 0 °C to 200 °C. In the preferred embodiment of the invention, sulfuric acid is used. In another embodiment of the present invention, the

temperature at which the acid charged is in the range of 10 °C to 100 °C, more preferably 50 °C to 100 °C.
The mixture is agitated for a predetermined time that is in the range of 0 minutes to 10 hours, more preferably between 0.5 hours to 5 hours. In the agitation stage, the pH of the reaction mixture is maintained throughout at a predetermined level that is in the range of 1 to 9, preferable range being 2 to 7.
At the end of the agitation stage, a reducing agent, preferably G-Cat is charged in suitable quantity. It is added either in its full required quantity or in any number of batches of any size, or continuously, or any combination thereof. The reducing agent is added over a predetermined period, at a predetermined temperature, and a predetermined pH. The period over which the reducing agent is added in the range of 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours. The temperature at which the reducing agent is added is in the range of 0 °C to 200 °C. The pH at which the reducing agent is added is in the range of 1 to 9, preferable range being 2 to 7.
In the preferred embodiment of the invention, G-Cat is used as the reducing agent and (Weight Ratio)RA is preferably in the range of 0.25 to 25, the more preferable range being 0.5 to 2.5. The quantity of the reducing agent used in Step 1.1, QRI i is variable in the range of 0% (w/w) to 100% (w/w) QRT.
In the subsequent cycles of the process of the present invention, Stream D is used as a reaction medium instead of FRM in the start-up (step l.l).
In another embodiment of the present invention, the temperature at which the reducing agent is charged is in the range of 10 °C to 100 °C, more preferably 50 °Cto 100 °C. G-Cat or any other customized proprietary catalytic formulation is used as the reducing agent in this embodiment.

In another embodiment of the present invention, the reaction medium or acid or a combination thereof, and the reducing agent are added in any sequence.
Step 1.2 - Reduction: The nitro or nitroso compound (respectively R-NO2 or R-NO) to be reduced is added to the reaction vessel either in its full quantity or in any number of lots. The total amount of R-NO2 or R-NO to be reduced is added over a period of 0 to 25 hours, at a suitable interval that depends on the molecule to be reduced.
A reaction medium is charged in suitable quantity to the reaction vessel while maintaining the temperature, and pH of the mixture in their respective predetermined ranges. The temperature at which the reaction medium is added is in the range of 0 °C to 200 °C. The pH at which the reaction medium is added is in the range of 1 to 9, preferable range being 2 to 7. In the preferred embodiment of the present invention, FRM is used as the reaction medium in step 1.2 of the first cycle of the process of the present invention. For subsequent cycle, stream D is used as the reaction medium for this step.
The quantity of the FRM or the reaction medium used in Step 1.2, denoted as QRM1.2, is variable in the range of 0% (w/w) to 40% (w/w) of the total quantity QRMT used in this cycle.
A suitable acid is optionally added to the reaction vessel to achieve the desired pH level of the reaction mixture. The acid is added in a suitable form while maintaining temperature of the reaction mixture in the reaction vessel in the range ofO°C to 200°C.
A reducing agent is charged to the reaction mixture. The reducing is charged over a period of time at a predetermined temperature which is in the range of 0°C to

200 C, when the pH of the reaction mixture is at a predetermined value which is in the range of 1 to 9, preferable range being 2 to 7. The reducing agent required for Step 1.2 is added either in a single lot or in batches, or continuously, or any combination of these methods of addition.
The quantity of the reducing agent used in this step, denoted as QRA1.2, is variable in the range of 0% (w/w) to 100% (w/w) of the QRT. The quantity QR! 2 is dictated by the requirement of the reduction potential for the R-NO2 or R-NO to be reduced. The quantity QRA1.2 is further determined so that it is the difference between QRAT and QRA 1.1. That is:
QRA1.2 = QRAT-QRA1.1 Equation 3
In the preferred embodiment of the invention, G-Cat is used as the reducing agent and (Weight Ratio)RA is preferably in the range of 0.25 to 25, the more preferable range being 0.5 to 2.5. In another embodiment of the present invention, any other reducing agent such as any proprietary agents is used as the reducing agent.
The reaction mixture at all stages of this step is optionally stirred with agitators rotating at a rate between 0 to 500 RPM. The step can be successfully carried out even without stirring.
Step 1.3 - Neutralisation: After completion of the reduction at the end of Step 1.2, optionally a suitable reaction medium is charged in suitable quantity to the reaction vessel. The decision to add the reaction medium depends on the consistency of the solids. The quantity of the reaction medium used in Step 1.3, denoted as QRM1.3, is variable in the range of 0% (w/w) to 40% (w/w) of the total quantity QRMT used in this cycle.
A neutralizing agent is added to the reaction mixture over a predetermined period and at a predetermined temperature to adjust its pH to a suitable level. The

fundamental role of the neutralisation agent is to provide a strong reduction potential for low concentration R-NO2 or R-NO tailing towards the end step 1.2 and providing the necessary neutralisation for the reaction mixture obtained at the end of step 1.2.
The period over which the neutralising agent is added is in the range of 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours. The temperature at which the neutralising agent is added is in the range of 0 °C to 200 C. The pH at which the neutralising agent is added is in the range of 1 to 12, preferably 4 to 11.
The neutralisation process wherein the neutralisation agent is allowed to react with R-NO2 or R-NO at a neutralisation process temperature and pH is continued for a neutralisation process time. The neutralisation process temperature is maintained in the range of 0 °C to 200 °C, and the neutralisation process pH is maintained between 1 to 12, preferably 4 to 11. The neutralisation process time is in the range of 0 hours to 10 hours, preferably in the range of 30 minutes to 5 hours.
In the preferred embodiment of the process of the invention the neutralising agent is in the form a formulation that comprises R-Cat or any combination thereof. The quantity of the neutralising agent, QNAT is determined by its weight ratio, denoted as (Weight Ratio)NA, that is the ratio of the weight of the neutralising agent required in a single cycle, WNA, to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle. That is,
(Weight Ratio)NA = WNA/ WN Equation 4
The QNAT is such that its weight is equal to WNA which is determined from Equation 3.

(Weigh Ratio)NA is preferably in the range of 0 to 2.5, more preferably between 0.05 to 0.25.
In the preferred embodiment of the invention, FRM is used as the reaction medium in the first cycle of this sequence, and for the subsequent cycles subject to the process of this invention, FRM is replaced by stream D,
In another embodiment of the present invention, any other neutralisation agents, proprietary or generic, are used. Neutralizing agent in the form of hydroxides of alkali metals like sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, carbonates or bicarbonates of alkali metals like sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, lithium carbonate, other such salts or any combination thereof is optionally used as a neutralising agent.
The inventors have surprisingly found that the action of G-Cat and R-Cat in the steps 1.1 to 1.3 collectively favours very high degree of chemo-selectivity and regio-selectivity for R-NO2 or R-NO to R-NH2 green reduction reaction.
The reaction mixture at all stages of this step is optionally stirred with agitators rotating at a rate between 0 to 500 RPM. The step can be successfully carried out even without stirring.
Step 1.4 - Separation: G-Cat, or R-Cat, or a combination thereof is added to the reaction mixture. The mixture thus formed is termed as the separation mixture. The quantity of the G-Cat and or R-Cat, or that of a combination thereof is in the range of 0% (w/w) to 5% (w/w) of R-NO2 or R-NO, preferable range being 0.5% (w/w) to 2.5% (w/w). It is charged at a predetermined Separation temperature and at predetermined Separation pH.

In the preferred embodiment of the present invention, the separation temperature is in the range of 0 to 200, and the separation pH is in the range of 1 to 12, preferably 4 to 11.
The pH and temperature conditions are maintained at this level of pH and temperature for predetermined time that is in the range of 0 hours to 24 hours, preferably in the range of 30 minutes to 5 hours.
Optionally a reaction medium is added to the separation mixture after or along with the addition of the agent R-Cat. It is added at a predetermined temperature which is in the range of 0 °C to 200 °C and pH that is in the range of 1 to 12, preferably 4 to 11.
For the subsequent cycles subject to the process of this invention, FRM is replaced by stream D.
In all of the above steps, that are steps 1.1 to 1.4, optionally sulfuric acid is used as the preferred suitable acid.
In another embodiment of the present invention, FRM is used as the reaction medium in the first cycle of the sequence. The quantity of the FRM or the reaction medium used in Step 1.4 QRM1.4 is variable in the range of 0% (w/w) to 40% (w/w) of QRMT used in this cycle.
The reaction mixture at all stages of this step is optionally stirred with agitators rotating at a rate between 0 to 500 RPM. The step can be successfully carried out even without stirring.
A single cycle of the green reaction sequence is complete at the end of step 1.4.

In another embodiment of the present invention, the separation temperature is preferably between 0°C to 100°C.
Sequence 2.0 - Green separation sequence:
As shown in Figure 2, this sequence comprises five steps, namely, a settling and decantation step, followed by filtration and decantation and two steps of stirring/settling/decantation, distillation and steam distillation. Each of these steps is described in detail.
Step 2.1 - Settling and Decantation: As shown in Figure 2, a reaction medium, referred to as the first settling RM, is optionally charged to the mixture obtained at the end of Step 1,4 in the reaction vessel in a suitable quantity and at suitable temperature and pH, the temperature being in the range of 0 to 200 and the pH being in the range of 1 to 12, preferably 4 to 11. The mixture thus formed is allowed to settle at a first settling pH, by maintaining it at a first settling temperature for a first settling time.
In the preferred embodiment of the invention the first settling pH is in the range of 1 to 12, preferably 4 to 11; the first settling temperature is in the range of 0°C and 200°C, preferably between 0°C to 100°C; and the first settling time is for 1 minute to 10 hours, preferably 30 minutes to 3 hours.
Liquid layer that forms as a result of the settling process is decanted at a first decanting temperature, first decanting pH and first decanting time and charged as Stream A to Step 2.5 of same cycle or any of the following cycles.
In the preferred embodiment of the invention, the first decanting temperature is in the range between 0 to 200, more preferably between 0 to 100, first decanting pH between 1 to 12, preferably between 4 to 11.

In the preferred embodiment of the invention FRM is used as the reaction medium in the first cycle, and for the subsequent cycles subject to the process of this invention, FRM is replaced by stream D.
The quantity of the FRM or the reaction medium used in Step 2.1, denoted as QRM2.1 is variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle.
Step 2.2 -Settling, Decantation and Filtration: The settled mass at the end of step 2.1 of the first cycle is referred to as a second settling RM, at a predetermined first filtrating temperature and a predetermined first filtrating pH at a predetermined first filtration time. The mixture is filtered. Filtrate is allowed to settle at a predetermined second settling pH, a predetermined second settling temperature for a predetermined second settling time.
Once the layers are separated, the organic layer is separated and collected (referred to as Stream B) is decanted at a predetermined second decantation temperature, a predetermined second decantation pH and at a predetermined second decantation time and charged to Step 2.5 of the same cycle or any of the following cycles.
In the preferred embodiment of the invention, FRM is used in the first cycle as the second settling RM, and for the subsequent cycles subject to the process of this invention, FRM is replaced by stream D; the values of the first stirring temperature, the first stirring continuation temperature, and the second decantation temperature are in the range of 0°C and 200°C, preferably between 0 °C to 100 C; the values of the first stirring pH, the first stirring continuation pH, and the second decantation pH are in the range of 1 to 12, preferably between 4 to 11; the values of the first stirring time, the first stirring continuation time, and the second

decantation time are in the range of 5 minutes to 5 hours; preferably 30 minutes to 3 hours.
The quantity of the FRM or the reaction medium used in Step 2.2, denoted as QRM2.2 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle.
In the preferred embodiment of the invention, the settled mass after decantation of stream B, is separated by known method of filtration.
The aqueous layer is separated and collected (referred to as Stream C) is filtrated at a predetermined filtration temperature, a predetermined filtration pH and at a predetermined filtration time and charged to mother liquor storage tank.
Step 2.3 - Stirring, Settling, and Decantation:
The settled mass at the end of step 2.2 of the first cycle is charged with a predetermined quantity of the solvent miscible or immiscible either high boiling or low boiling , referred to as a third settling RM, at a predetermined second stirring temperature and a predetermined second stirring pH at a predetermined second stirring time. The mixture is stirred. Stirring is continued by maintaining the mixture at a predetermined second stirring continuation temperature, a predetermined second stirring continuation pH for a predetermined second stirring continuation time. Stirring is stopped and mass is allowed to settle at a predetermined third settling pH, a predetermined third settling temperature for a predetermined third settling time.
Once the layers are separated, the organic layer collected at the top (referred to as Stream E) is decanted at a predetermined third decantation temperature, a predetermined third decantation pH and at a predetermined third decantation time and charged to a washings storage tank.

In the preferred embodiment of the invention, FRM is used in the first cycle as the third settling RM, and for the subsequent cycles subject to the process of this invention, FRM is replaced by stream G; the values of the second stirring temperature, the second stirring continuation temperature, and the third decantation temperature are in the range of 0 °C and 200 °C, preferably between 0 °C to 100 °C; the values of the second stirring pH, the second stirring continuation pH, and the third decantation pH are in the range of 1 to 12, preferably between 4 to 11; the values of the second stirring time, the second stirring continuation time, and the third decantation time are in the range of 5 minutes to 5 hours; preferably 30 minutes to 3 hours.
The quantity of the FRM or the reaction medium used in Step 2.3, denoted as QRM2.3 IS variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle.
As a novel feature of the present invention, Step 2.3, which is similar to step 2.2, is carried out to ensure maximum removal of R-NH2 by the reaction medium from the inorganic by-product.
Step 2.4 - Separation: In all cycles of the separation sequence, reaction medium is charged into the reaction vessel to at the end of step 2.3. The separation mixture thus obtained is then filtered to separate the inorganic by-product by known methods of separation i.e filtration. Filtration is continued at a predetermined filtration temperature for a predetermined filtration time. Filtration is stopped and liquid stream obtained at the end of Step 2.4 is charged as Stream F to washing storage tank.
In the preferred embodiment, the separation temperature is in the range between 0°C and 200°C, preferably between 0 °C to 100 °C, the pH is between 1 to 12,

preferably between 4 to 9, and the separation time is between5 minutes to 5 hours; preferably 30 minutes to 3 hours.
The quantity of the FRM used in Step 2.4 QRM2.4 is variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle.
Step 2.5 -Steam Distillation of R-NH2 : Combined liquid streams (Stream A from Step 2.1 and Stream B from Step 2.2) obtained during this sequence are charged into another reaction vessel with other attachments known to a person skilled in the art.
In the preferred embodiment, R-NH2 is separated from the reaction medium by predetermined steam distillation temperature and predetermined pH in the range of 5.0 to 12.0, preferable 7.0 to 11 optionally by solvent saturation or by distillation or by salting or by any other physical layer separation method known in the art in the predetermined time in the range of 5 minutes to 10 hrs, preferably 30 minutes to 5 hours.
A key advantageous feature of the present invention is that a part of the stored liquid, said part being defined as the stream D, in suitable quantity is recycled into various steps (Step 1.1 to 1.4 and 2.2) of the following cycles of the process of the invention.
The quantity of the FRM used in Step 2.6, denoted as QRM2.6 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle.
A typical cycle of the process of the present invention, that is a cycle consisting a green reaction sequence and a green separation sequence, ends here. A key feature of the present invention is that all steps of a typical cycle are carried out at atmospheric pressure.

As a key advantageous feature of the present invention, the reaction medium used both the green reaction sequence and the green separation sequence, in the cycles after the first cycle is taken from the mother liquor and various streams generated during the process of this invention. In other words, the FRM used in the various stages (Steps 1.1 to 1.4 and 2.1 to 2.3) of the first cycle is replaced by a suitable reaction medium in all subsequent cycles.
In steps 2.4 and 2.6 FRM is used in all cycles to make up the losses of previous cycles in the process of this invention.
The inventors of the present invention have found that the purity of R-NH2 after drying in any cycle varies in the range of 75% to 100%, preferably 80% to 99.9%.
The mother liquor and washings comprising water or solvent or combination thereof obtained during various steps described above are stored for processing in further cycles, number of recycles being generally in the range of 5 to 100 and above.
The inventors have surprisingly found that the reduction of R-NO2 or R-NO to R-NH2 carried out with the process described above generates inorganic by-product in any cycle in the ratio of weight in the range of 0.25 to 25 to the weight of R-NO2 or R-NO to be reduced of the above sequence is crystalline and non-sticky in nature. Color of these by-product ranges from brown to jet-black particularly jet-black. The pH of the inorganic by-product is in the range of 4.0 to 8.0. The moisture content of the inorganic byproduct is in the range of 5% to 50%, particular range being ) 0% to 30%.
The inventors have found that the process of the present invention is applicable to the R-NO2 or R-NO compounds having one or more nitro groups including

aromatic R-NO2 or R-NO compounds like nitrobenzene, nitronaphthalenes, nitroanthracenes, nitrophenanthrenes, heterocyclic nitro compounds with one or more hetero atoms either same or different, aliphatic nitro compounds and all such other nitro compounds.
Experimental procedures:
Example 1: Ortho Nitro Anisole to Ortho Anisidine.
Fresh cycle: In a round bottom flask equipped with stirrer, condenser, thermometer, addition port arranged in suitable heating/cooling system was charged 400 ml water, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30 minute at 95°C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 80.39gm of amine with purity of 99.8%

First Recycle (R1): In the same set up as described above, 730 ml reaction medium generated in fresh cycle, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30 minute at 95°C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 90.30gm of amine with purity of 99.50%
Second Recycle (R2): : In the same set up as described above, 737 ml reaction medium generated in first cycle, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C, Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30

minute at 95°C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 88.54gm of amine with purity of 99.70%
Third Recycle (R3): In the same set up as described above, 740 ml reaction medium generated in second cycle, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30 minute at 95°C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 91.92gm of amine with purity of 99.60%

Fourth Recycle (R4): In the same set up as described above, 733 ml reaction medium generated in third cycle, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30 minute at 95°C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 95.45gm of amine with purity of 99.50%
Fifth Recycle (R5): In the same set up as described above, 735 ml reaction medium generated in fourth cycle, heated to 80°C. 101.2 g G-CAT was charged in start up with continuous stirring at 80°C & stir for 15 mins. 20 g of nitro compound, 80 ml water and 6.76 g of G-CAT was added in 10 mins. The reaction mass was then raised to 98°C. The reaction mass was maintained for 5-10 min at 98°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed for first lot. Reaction is continued till all nitro compound was consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, maintain the batch for30 min. and checked pH. 6.9 gm of R-CAT was charged slowly in 30

minute at 950C. Reaction mass was maintained for 1 hr at 95°C after addition was over and checked pH. After neutralization, the reaction mass was left to settle and then organic layer was decanted at 95°C. Then aqueous layer was filtered in hot condition and organic layer was separated from filtrate. The entire amine layer was combined together. 400 ml methanol was charged to the aqueous layer and stir the reaction mass and after 15 mins separated the organic layer. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 91.90gm of amine with purity of 99.70%
Example 2: 5-Chloro-2-Methoxy Nitrobenzene to 5-Chloro-2-Methoxy Aniline.
Fresh cycle: In a round bottom flask equipped with stirrer, condenser, thermometer, addition port arranged in suitable heating/cooling system, 240 ml water, 2 ml H2S04 was charged and adjusted pH to 4.0. Then it was heated to 100°C. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for lhr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic

layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 14 gm of amine.
First Recycle (Rl): In the same set up as described above, 330 ml reaction medium generated in fresh cycle, 2 ml H2S04 was charged and adjusted pH to 4,0. Then it was heated to 100°C. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for lhr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 15.2 gm of amine.
Second Recycle (R2): In the same set up as described above, 337 ml reaction medium generated in first cycle, 2 ml H2S04 was charged and adjusted pH to 4.0. Then it was heated to 100°C. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then

heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for lhr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 16.5 gm of amine.
Third Recycle (R3): In the same set up as described above, 340 ml reaction medium generated in second cycle, 2 ml H2SO4 was charged and adjusted pH to 4.0. Then it was heated to 100°C. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for lhr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer

was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 17 gm of amine.
Fourth Recycle (R4): In the same set up as described above, 343 ml reaction medium generated in third cycle, 2 ml H2SO4 was charged and adjusted pH to 4.0. Then it was heated to 100°C. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for lhr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 18.2 gm of amine.

Fifth Recycle (R5): In the same set up as described above, 345 ml reaction medium generated in fourth cycle, 2 ml H2SO4 was charged and adjusted pH to 4.0. Then it was heated to 100X. 50 g G-CAT was charged in start up with continuous stirring at 100°C and stir for 15 mins. 30 g of nitro compound on as is basis and 5 g of G-CAT was charged in 10 mins. The reaction mass was then heated to 98°C and was maintained for 5-10 min at 100°C. Remaining G-CAT and Nitro compound was charged in four equal lots in similar manner as followed the process of first lot. Reaction was continued till all nitro compounds get consumed in the reaction. Completion of reaction was checked by TLC for disappearance of nitro compound. After reduction was over, the reaction mass was maintained 30 min. and checked pH. 4 gm of R-CAT was slowly charged in 30 minute at 95°C and maintained for Ihr at 95°C and checked pH. After completion of neutralization process, the reaction mass was left to settle. Organic layer was decanted at 95°C and aqueous layer was filtered in hot condition. Organic layer was separated from filtrate. The entire amine layer was combined together. 600 ml methanol was charged to the aqueous layer and stirred the reaction mass and 15 mins organic layer was separated. The process was repeated for one more extraction. The methanol layer was then combined and distilled to remove methanol. The residual amine was then combined to other amine layer and steam distilled to obtain 18.0 gm of amine.

The following table (Table 04) illustrates the savings in the quantities of fresh water and solvent used and recycled mother liquor & solvent in the reaction of the present invention of- O-Nitro Anisole to Ortho Anisidine

Cycl e Basi
s H20&ML
consumption &
saving Solvent consumption & saving

[1] g Treated mother liquor Fres
h Cycle No. Recycl
e solvent
Qty.
(ml) Dry wt Purit
y

H20 ML From Cycle
No. (ml) No. (ml) g %
0 100 800 0 800 0 0 80.39 99.87
1 100 70 730 0 160 Cycle-0 640 90.30 99.50
2 100 63 737 1 160 Cycle-1 640 88.54 99.70
3 10 60 740 2 160 Cycle-2 640 91.92 99.60
4 100 67 733 3 160 Cycle-3 640 95.45 99.50
5 100 65 735 4 160 Cycie-4 640 91.90 99.70
1) Water required for one experiment = 800 g
2) Water required for six experiments = 4800 g
3) Actual water used in six experiments = 1125 g
4) Total water saved by the use of the invention (%) = 76.56%
5) Solvent required for one experiment = 800 ml
6) Solvent required for six experiments = 4800 ml
7) Actual solvent used in six experiments = 1600 ml
9) Total solvent saved by the use of the invention (%) = 67%

The following table (Table 04) illustrates the savings in the quantities of fresh water & solvent used and mother liquor & solvent recycled in the reaction of the present invention of 5-Chloro-2-Methoxy Nitrobenzene to 5-Chloro-2-Methoxy
Aniline.

Cycle Basis H20 & ML consumption & saving Solvent consumption & saving

(1)
e Treated mother liquor Fresh Cycle No. Recycle solvent
Qty.
(ml) Dry wt

H20 ML From (ml) No. (ml) g
0 30 340 0 1200 0 0 14
1 30 10 330 Cycle-0 240 Cyc!e-0 960 15.2
2 30 03 337 Cycle-1 240 Cycle-1 960 16.5
3 30 0 340 Cycle-2 240 Cycle-2 960 17
4 30 0 343 Cycle-3 240 Cycle-3 960 18.2
5 30 0 345 Cycle-4 240 Cycle-4 960 18
1) Water required for one experiment = 340 g
2) Water required for 6 experiments = 2040 g
3) Actual water consumed in 6 experiments = 353 g
4) Total % Saving of Water = 82.69%
5) Solvent required for one experiment = 1200 ml
6) Solvent required for 6 experiments = 7200 ml
7) Actual solvent consumed in 6 experiments = 2400 ml
8) Total % saving of Solvent = 66.66%

Based on the foregoing discussion it is clear that the present invention comprises the following items:
1. A sustainable chemical process of green reduction of nitro-compounds, R-
NO2, or nitroso compounds, R-NO, into corresponding amino - compounds,
R-NH2, comprising a plurality of cycles, each of said cycles comprising a
green reaction sequence and a green separation sequence, wherein said green
separation sequence follows said green reaction sequence.
2. A process as described in item 1, wherein the number of said plurality of cycles is preferably greater than 3, more preferably greater than 10, even more preferably greater than 25.
3. A process as described in any of items 1 and 2,
Wherein said green reaction sequence of a typical said cycle comprises the following steps:
Step 1.1 - creating start-up conditions for the reduction process, said Step 1,1 further comprising the following stages:
Stage 1.1a. charging a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as start-up RM, to a first reaction vessel with an agitator and other attachments known to a person skilled in the art; thereby forming the start-up reaction mixture, denoted as SRM;
wherein the quantity of the reaction medium used in Step 1.1. denoted as QRM1.1, is variable, said QRM1.1 being in the range of 0% (w/w) to 40% (w/w) of QRMT used in this cycle;
wherein said QRMT is the total quantity of the reaction medium used in this cycle, said QRMT being determined such that the ratio, denoted as (Weight

Ratio)RM, of the weight of said QRMT, WRM, to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle WN; the relationship between (Weight Ratio)RM, WRM, and WN being represented by the equation
(Weight Ratio)RM = WRM/ WN;
and wherein said (Weight Ratio)RM is preferably in the range of 5 to 100, the more preferable range being 10 to 75, and;
stage 1.1b. further optionally charging to said first reaction vessel a first suitable acid, preferably sulfuric acid, in a suitable quantity, and in suitable form, said suitable form being solid, liquid, or any combination thereof, to said SRM such that the pH of said SRM is in the range between 1 to 9, preferably between 3 to 7, more preferably between 4 to 6; wherein said acid is added at a start-up temperature which is in the range between 0 °C to 200 °C;
stage 1.1c. agitating the mixture thus formed for a duration in the range of 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours, while maintaining the pH of the mixture during the agitation stage of stage 1.1c in the range between 1 to 9, preferably between 3 to 7, more preferably between 4 to 6, and while maintaining the temperature of the mixture during the agitation stage of stage 1.1c in the range between 0 °C to 200 °C; and
stage l.ld. adding to said first reaction vessel, upon completion of the agitation stage of stage 1.1c, a reducing agent, RA1.1 in suitable quantity which is denoted as QRAI.I, said QRAI.I being variable in the range of 0% to 100%oQRAT;

wherein said QRAT is the total quantity of the reducing agent used in this cycle; said QRAT being determined such that the ratio, denoted as (Weight Ratio)RA, of the weight of said QRAT, WRA, to the weight of total amount of R-N02 or R-NO to be reduced in that single cycle, WN; wherein the relationship between (Weight Ratio)RA, WRA, and WN is represented by the equation:
(Weight Ratio)RA = WRA/ WN ;
and wherein said (Weight Ratio)RA is preferably in the range of 0.25 to 25, the more preferable range being 0.5 to 2.5;
wherein said reducing agent is added either in its full required quantity, QRAT, or in batches, or continuously, or as any combination of these methods of addition, over a period of 0 minutes to 5 hours, preferably 0.5 hours to 2.5 hours; and wherein the pH of the mixture in said first reaction vessel at the time of addition of said reducing agent is between 1 to 9, preferably between 2 to 7;
Step 1.2 - reducing the nitro or nitroso compound to be reduced, wherein said Step 1.2 further comprises the following stages:
stage 1.2a. adding R-NO2 or R-NO, respectively a nitro or nitroso compound to be reduced, to said reaction vessel in solid or liquid form dissolved in water or water immiscible solvent either high boiling or low boiling or combination thereof or any other known form over a suitable reduction period in the range of 0 to 25 hours;

stage 1.2b. charging a suitable reaction medium, denoted as reduction RM, in suitable quantity to said first reaction vessel;
stage 1.2c. further optionally adding to said first reaction vessel a second suitable acid, preferably sulfuric acid, to bring the pH value of the mixture thus formed, referred to as reduction mixture, with in the range between 1 to 9, preferably between 2 to 7, more preferably between 4 to 6, while maintaining the temperature of the mixture formed by addition the acid to said reduction mixture between 0 °C to 200 °C; and
stage 1.2d. adding a reducing agent, RA1.2, to said first reaction vessel, wherein said RA1.2 is added either simultaneously with the R-NO2 or R-NO compound to be reduced in stage 1.2a, or after the addition of acid of stage 1,2c, thereby forming a reduction agent mixture; wherein said RA1.2 is added at a reduction time such that the pH of said reduction agent mixture is in a range between 1 to 9, preferably between 2 to 7, more preferably between 4 to 6, and such that the temperature of said reduction mixture is in the range between 0 °C to 200 °C;
wherein the quantity of RA1.2, denoted as QR1.2, is such that said QR1.2 is the difference between QRT and QR1.1;
Step 1.3 - neutralizing the reaction mixture obtained at the end of Step 1.2, wherein said neutralization is carried out in the following stages:
stage 1.3a. optionally adding a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as neutralization RM, in a suitable quantity to said reaction vessel, wherein quantity of the reaction medium used in Step 1.3, denoted as QRM1.3, is variable in the range of 0% (w/w) to 40% (w/w) of QRMT;

stage 1.3b. adding to the reaction mixture obtained at the end of step 1.3a in said first reaction vessel a neutralizing agent, NA1.3, wherein the quantity of said neutralizing agent used, QNAT, is the total quantity of the neutralizing agent to be used in this cycle; said QNAT being determined such that the ratio, denoted as (Weight Ratio)NA, of the weight of said QNAT, WNA, to the weight of total amount of R-N02 or R-NO to be reduced in that single cycle, WN; wherein the relationship between (Weight Ratio)NA, WNA, and WN is represented by the equation:
(Weight Ratio)NA = WNA/WN;
and wherein said (Weight Ratio)NA is preferably in the range of 0 to 2.5, the more preferable range being 0.05 to 0.25; and
wherein said neutralizing agent is added over a period in the range between 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours, at a temperature in the range between 0 °C to 200 °C, and at a pH in the range between 1 to 9, preferably 2 to 8;
wherein R-Cat or G-Cat is used as the preferred neutralizing agent; and
stage 1.3c. allowing the neutralization of the mixture obtained at the end of stage 1.3b containing R-NO2 or R-NO compound to take place at a temperature between 0 °C to 200 °C, at a pH between 1 to 9, preferably 2 to 8, said neutralization being carried out over a period between 0 hours to 10 hours, preferably in the range of 30 minutes to 5 hours;
wherein the contents of said first reaction vessel during any or all stages of 1.3 a to 1.3 c are optionally stirred for any duration of the individual stages using said agitator rotating at a rate between 0 to 500 R?M;

Step 1.4 - Isolating the appropriate part of the contents of the said first reaction vessel obtained at the end of Step 1.3, wherein the isolation process comprises the following stages:
stage 1.4a. charging to the reaction mixture obtained at the end of stage 1.3c, R-Cat or G-Cat, wherein the quantity of said R-Cat or G-Cat being such that its weight ratio with R-N02 or R-NO is in the range of a 0.05 w/w to 5 w/w, preferable range being 0,5 w/w to 2.5 w/w, thereby forming an isolation reaction mixture, at a time such that the pH of said isolation reaction mixture is in the range of 1 to 12, preferably 4 to 11;
stage 1.4b. optionally adding a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as separation RM, after completion of or any time during stage 1.4a, at a temperature between 0 °C and 200 °C, and at pH level between the range ofl to 12 preferably 4 to 11; and
stage 1.4c. maintaining the separation mixture obtained at the end of stage 1.4b at a temperature between 0 °C and 200 °C, preferably between 0°C to 100°C, for a period in the range of 0 hours to 24 hours, preferably in the range of 30 minutes to 5 hours;
whereby a single cycle of said green reaction sequence is completed, and where after a cycle of green separation sequence is carried out, said green separation sequence comprising the following steps:
Step 2.1 - applying settling and decantation to the contents of said reaction vessel obtained at the end of said step 1.4, wherein said settling and decantation comprises following stages:

stage 2.1a. optionally charging a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as first settling RM, to the reaction mixture obtained at the end of step 1.4, maintaining the temperature of the mixture in the range between 0°C and 200 °C, and the pH of the mixture in the range between 1 to 12, preferably between 4 to 11; wherein the quantity of said first settling RM used, denoted as QRM2.1, is variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle.
stage 2.1b. allowing the reaction mixture obtained at the end of stage 2.1b to settle down for a first settling time while maintaining the temperature of the mixture in the range between 0 °C and 200 °C, and the pH of the mixture in the range between 1 to 12, preferably between 4 to 11; wherein said first settling time is in the range between I minute to 10 hours, preferably between 30 minutes to 3 hours;
stage 2.1c. decanting the organic liquid layer formed at the end of stage 2.1c at a first decanting temperature in the range between 0 °C and 200 °C, a first decanting pH in the range between 1 to 12, preferably between 4 to 11 and first decanting time in the range between 1 minute to 10 hours, preferably between 30 minutes to 3 hours, and charging the decanted liquid said Stream A to Step 2.5 of same cycle or any of the following cycles;
Step 2.2 - Stirring, settling, decanting and filtration the contents obtained at the end of Step 2.1, the filtrating, settling and decanting comprising the following stages:
stage 2.2a. filtration temperature and a predetermined first stirring pH at a predetermined first stirring time;

stage 2.2b. filtrating the mixture of stage 2.2a by maintaining the mixture at a predetermined first filtrating temperature, a predetermined first filtration pH for a predetermined first filtration time;
stage 2.2c. allowing the mixture of stage 2.2 b to settle at a predetermined second settling pH, a predetermined second settling temperature for a predetermined second settling time; and
stage 2.2d. decanting the organic liquid layer collected at the end of stage 2.2c, the liquid layer denoted as Stream B, at a predetermined second decantation temperature, a predetermined second decantation pH and at a predetermined second decantation time; said Stream B being charged to Step 2.5 of the same cycle or any of the following cycles;
wherein the values each of said first stirring temperature, said first stirring continuation temperature, and said second decantation temperature are in the range of 0°C and 200°C, preferably between 0 °C to 100 °C; the values of each of said first stirring pH, said first stirring continuation pH, and said second decantation pH are in the range of 1 to 12, preferably between 4 to 11; the values of each of said first stirring time, said first stirring continuation time, and said second decantation time are in the range of 5 minutes to 5 hours; preferably 30 minutes to 3 hours; and
wherein the quantity of the reaction medium used in Step 2.2, denoted as QRM2.2 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle.
Wherein the settled mass after decantation of stream B, is separated by known filtration methods;

the aqueous layer is separated and collected (referred to as Stream C) is filtrated at a predetermined filtration temperature, a predetermined filtration pH and at a predetermined filtration time and charged to mother liquor storage tank.
Step 2.3 - stirring, settling, and decanting the contents at the end of Step 2.2 in the following stages:
stage 2.3a. charging to said reaction vessel a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as third settling RM, at a predetermined second stirring temperature and a predetermined second stirring pH at a predetermined second stirring time;
stage 2.3b. stirring and continuing to stir the mixture of stage 2.3 a by maintaining the mixture at a predetermined second stirring continuation temperature, a predetermined second stirring continuation pH for a predetermined second stirring continuation time;
stage 2.3c. stopping the stirring action and allowing the mixture of stage 2.3 b to settle at a predetermined third settling pH, a predetermined third settling temperature for a predetermined third settling time; and
stage 2.3d. decanting the liquid layer collected at the end of stage 2.3 c near the top of said reaction vessel, the liquid layer denoted as Stream C, at a predetermined third decantation temperature, a predetermined third decantation pH and at a predetermined third decantation time; said Stream C being charged to a washings storage tank;

wherein the values each of said second stirring temperature, said second stirring maintenance temperature, said third settling temperature, and said third decantation temperature are in the range of 0°C and 200°C, preferably between 0 °C to 100 °C; the values of each of said second stirring pH, said second stirring maintenance pH, said third settling pH, and said third decantation pH are in the range of 1 to 12, preferably between 4 to 11; the values of each of said second stirring time, said second stirring maintenance time, said third settling time, and said third decantation time are in the range of 5 minutes to 5 hours; preferably 30 minutes to 3 hours; and
wherein the quantity of the reaction medium used in Step 2.3, denoted as QRM2.3 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle.
Step 2.4 - Separation of the inorganic by-product and reaction medium from the mass which is miscible or immiscible either high boiling or low boiling at the end of step 2.3 by known filtration methods, said separating and washing comprises the following stages:
stage 2.4a. charging to said first reaction vessel a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as first separation and washing RM; wherein the quantity of said first separation and washing RM, denoted as QRM2.4, is variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle.
stage 2.4b. filtrating the mixture obtained at the end of stage 2.4a at a predetermined filtration temperature in the range of 0°C and 200°C, a predetermined filtration pH in the range of 1 to 12, preferably between 4

to 11, and a predetermined separation time in the range of 5 minutes to 5 hours; preferably 30 minutes to 3 hours;
stage 2.4c. stopping the filtration and separating residual inorganic byproduct obtained at the end of stage 2.4 b by any of commonly known methods;.
Step 2.5 - separating amino compounds by a method comprising the following stages:
stage 2.5a. charging said Stream A. of Step 2.1, said Stream B of Step 2.2, either individually or in any combination, to a second reaction vessel equipped with an agitator and other attachments known to person skilled in the art;
stage 2.5b. distillating the mixture obtained at the end of stage 2.5 a at a second separation temperature that is in the range between 0 °C and 200 °C, preferably in the range between 0 °C and 100°C, a second distillation pH that is in the range between 1 to 12, preferably between 4 to 9, and for a second distillation time that is in the range between 5 minutes to 5 hours; preferably 30 minutes to 3 hours; and
stage 2.5c. stopping the distillation action and separating the amino compounds formed during the earlier steps is steam distilled at the period over which the temperature reduction is carried out is in the range between 5 minutes to 10 hours, more preferably between 30 minutes to 3 hours; and wherein the third separation temperature is in the range between 0 °C to 200 °C, more preferably between 0 °C to 100 °C;

4. A process as described in item 3, wherein in the first cycle of said green reaction sequence, a fresh reaction medium (FRM) is used as the reaction medium in any or all of Steps 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, and 2.6, that is said FRM is used as any or all, or any combination thereof, of said start-up RM, said reduction RM, said neutralization RM, said separation RM, said first settling RM, said second settling RM, said third settling RM, said first separation and washing RM, and washing RM.
5. A process as described in any of items 3 and 4, wherein for any cycle following the first cycle a fresh portion of the liquid stored in said washings storage tank is used as the reaction medium in any of Steps 1.1, 1.2, 1.3, 1.4, 2.1, and 2.2, that is the fresh portion of the liquid stored in said washings storage tank is used as any or all, or any combination thereof, of said start-up RM, said reduction RM, said neutralization RM, said purification RM, said first settling RM, said second settling RM.
6. A process as described in any of items 3 to 5, wherein the temperature in any or all of the stages 1.1 b, 1.1 c, 1.2 c, 1.2 d, 1.3 b, 1.3 c, 1.4 b, 1.4 c, or a combination thereof, is in the range of 50 °C to 100 °C.
7. A process as described in any of items 3 to 6, wherein said first suitable acid and said second suitable acid are sulphuric acid.
8. A process as described in any of items 3 to 7, wherein the reducing agents of steps 1.1 and 1.2, namely said RA1.1 and RA1.2 are G-Cat or any other reduction agent.
9. A process as described in any of items 3 to 8, wherein the neutralisation agent of Step 1.3 is R-Cat or G-Cat or any combination thereof, or any other proprietary neutralisation agent used on its own or in any combination with a combination of R-Cat or and G-Cat.

10. A process as described in any of items 3 to 9, wherein the nitro compound to
be reduced is added to the step 1.2 in its entire quantity or in batches of any
size at any interval.
11. A process as described in any of items 3 to 10, wherein the individual stages
of step 1.2 are carried out in any sequence.
12. A process as described in any of items 3 to 11, wherein a salt of iron with
inorganic or organic acids, preferably selected from a group of salts
comprising ferrous sulphate, ferrous chloride, ferrous ammonium sulphate,
ferrous oxalate, ferrous citrate, or any combination thereof, or a salt selected
from a group comprising ammonium chloride, ammonium sulphate, other
such salts, or any combination thereof, is used in place of said first suitable
acid of step 1.1b.
13. A process as described in any of items 3 to 12, wherein said neutralising agent
of stage 1.3b is selected from a group comprising hydroxides, carbonates, or bicarbonates of alkali metals, either individually or in any combination thereof; said hydroxides preferably being sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide; said carbonates preferably being sodium carbonate, potassium carbonate, calcium carbonate, or lithium carbonate; said bicarbonates preferably being sodium bicarbonate, potassium bicarbonate, lithium bicarbonate.

We Claim:
1. A sustainable chemical process of reduction of nitro-compounds, R-NO2, or nitroso compounds, R-NO, into corresponding amino-compounds, R-NH2, said process comprising a reaction sequence followed by a isolation sequence, characterised in that the product isolation is carried out by steam distillation and wherein said reaction sequence and said isolation sequence are carried out in a steady state closed loop circuit capable of inherently and intrinsically recycling at source level all mother liquor generated, with plurality of cycles, as shown in figure 5, wherein fresh water or any other solvent is added only to make up for systemic losses such as by evaporation, said mother liquor being any of the reaction medium, extraction medium, or wash medium, or any combination thereof, used in said process.
2. A process as claimed in claim 1, wherein said reaction sequence of a typical said cycle comprises the steps 1.1 to 1.4 as below:
step 1.1- creating start-up conditions for the reduction process by charging a start-up reaction medium to a first reaction vessel to which a reducing agent is added, characterized in that for all cycles following the first cycle said start-up reaction medium used for forming the start-up reaction mixture is drawn from a mother liquor storage tank in which liquid streams generated in said isolation sequence of said process are stored;
step 1.2 - charging the nitro or nitroso compound to be reduced in the reaction vessel, and reducing it by charging a reduction reaction medium, and a further quantity of the reducing agent, in suitable quantities to said first reaction vessel, characterized in that for all cycles following said first cycle said reduction reaction medium is drawn from said mother liquor storage tank;

step 1.3 - neutralizing the reaction mixture obtained at the end of step 1.2, by adding a neutralizing reaction medium to which a first neutralizing agent is added, characterized in that for all cycles following the first cycle the neutralization reaction medium used for neutralizing is drawn from said mother liquor storage tank;
step 1.4 - isolating the appropriate part of the contents of the said first reaction vessel obtained at the end of step 1.3 by adding a suitable isolation reaction medium and a second neutralisation agent, characterised in that for all cycles following the first cycle said purification reaction medium used for the purification process is drawn from said mother liquor storage tank;
whereby a single cycle of said reaction sequence is completed, and whereafter a cycle of isolation sequence is carried out, said isolation sequence comprising the steps 2.1 to 2.5 as below:
step 2.1 - optionally charging a first settling reaction medium to the contents of said reaction vessel obtained at the end of said step 1.4 and settling the reaction mixture followed by decantation, characterised in that the decanted liquid, denoted as Stream A, is used as a reaction medium in step 2.5 of said isolation sequence and that for all cycles following said first cycle said first settling reaction medium charged to said reaction vessel for aiding the settling process is drawn from said mother liquor storage tank;
step 2.2 - charging a second settling reaction medium to the contents obtained at the end of step 2.1, followed by filtration, stirring, and decanting, characterised in that the decanted liquid, denoted as Stream B, is used as a reaction medium in step 2.5 of said isolation sequence and that for all cycles following said first cycle said second settling reaction medium added to the

reaction vessel to aid further settling is drawn from said mother liquor storage tank;
stirring and filtrating the mass at the end of step 2.2 characterized in that the filtrated aqueous liquid, denoted as Stream C, is collected in a mother liquor storage tank to recycle in that for all cycles following the first cycle
step 2.3 - charging a third settling reaction medium to the contents at the end of step 2.2 followed by stirring, settling, and decanting, characterized in that the liquid layer collected at the end of settling of step 2.3, denoted as Stream E, is collected in a washings storage tank from where some of it is charged, as Stream H, to said mother liquor storage tank of step 2.2 in order to replenish said mother liquor storage tank, and in that for all cycles following the first cycle the third settling medium is drawn from said washings storage tank;
step 2.4 - charging the separation reaction medium to the contents at the end of step 2.3 followed by stirring and separating the content by known filtration methods, characterized in that the liquid layer collected at the end of filtration of step 2.4, denoted as Stream F,
step 2,5 - charging the stream A of step 2.1, stream B of step 2.2 , followed by distillation and separation of the amino compound.
3. A process as claimed in any of claims 1 and 2, wherein said number of cycles is between 2 and 25.
4. A process as claimed in any of claims 1 and 2, wherein said number of cycles is between 25 and 100.
5. A process as claimed in any of claims 2-4, wherein

said step 1.1 further comprising the following stages:
stage 1.1a: said start-up reaction medium, denoted as start - up RM, is
charged to said first reaction vessel thereby forming the start-up reaction
mixture,
stage 1.1b: further optionally charging to said first reaction vessel a first
suitable acid, preferably sulfuric acid, or a salt of iron with inorganic or
organic acids, to said start-up reaction medium
stage 1.1c: agitating the mixture thus formed
stage l.ld: adding to said first reaction vessel, upon completion of the
agitation stage of stage 1.1c, a reducing agent, RA1.1;
said step 1.2 further comprises the following stages:
stage 1.2a: adding R-NO2 (nitro) or R-NO (nitroso), to said reaction vessel;
stage 1.2b: charging said reduction reaction mixture, denoted as reduction RM in suitable quantity to said first reaction vessel;
stage 1.2c: further optionally adding to said first reaction vessel a second suitable acid, preferably sulfuric acid, and
stage 1.2d: adding a reducing agent, RA1.2, to said first reaction vessel,
wherein said step 1.3 is carried out in the following stages:
stage 1.3a: optionally adding said neutralization reaction medium, comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, to said reaction vessel,

stage 1.3b: adding to the reaction mixture obtained at the end of step 1.3a in said first reaction vessel said first neutralizing agent in the form of R-Cat or G-Cat, or a combination thereof, denoted as NAi.3, and
stage 1.3c: allowing the neutralization of the mixture obtained at the end of stage 1.3b containing R-NO2 or R-NO compound to take place;
wherein said step 1.4 comprises the following stages:
stage 1.4a: charging to the reaction mixture obtained at the end of stage 1.3c, said second neutralisation agent in the form of R-Cat or G-Cat, stage 1.4b: optionally adding said suitable reaction medium, comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted separation RM, after completion of or any time during stage 1.4a,
stage 1.4c maintaining the separation mixture obtained at the end of stage 1.4b so that separation takes place
wherein said step 2.1 comprises following stages:
stage 2.1a: optionally charging said suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as first settling RM, to the reaction mixture obtained at the end of step 1.4,
stage 2.1b: allowing the reaction mixture obtained at the end of stage 2.1 b to settle down for a first settling time and
stage 2.1c: decanting the liquid layer formed at the end of stage 2.1c at a first decanting temperature and charging the decanted liquid Stream A to step 2.5 of same cycle or any of the following cycles;

wherein said step 2.2 comprises the following stages:
stage 2.2a: settled mass at the end of stage 2.1c, denoted as second settling RM;
stage 2.2b: filtrating the mixture of stage 2.2a
stage 2.2c: allowing the mixture of stage 2.2b to settle; and
stage 2.2d: decanting the liquid layer collected at the end of stage 2.2c, the liquid layer denoted as Stream B; said Stream B being charged to step 2.5 of the same cycle or any of the following cycles;
the content at the end of stage 2.2d is filtered and the aqueous liquid layer collected denoted as Stream C; said Stream C being charged to mother liquor storage tank;
wherein said step 2.3 comprises the following stages:
stage 2.3a: charging to said reaction vessel a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as third settling reaction mixture,
stage 2.3b: stirring and continuing to stir the mixture of stage 2.3a;
stage 2.3c: stopping the stirring action and allowing the mixture of stage 2.3b to settle and
stage 2.3d: decanting the liquid layer collected at the end of stage 2.3c near the top of said reaction vessel, the liquid layer denoted as Stream E; said Stream E being charged to a washings storage tank;

wherein said step 2.4 comprises the following stages:
stage 2.4a: charging to said first reaction vessel with a suitable reaction medium comprising water or water immiscible solvent either high boiling or low boiling or combination thereof, denoted as first separation and washing RM;
stage 2.4b: stirring and continuing to stir the mixture of stage 2,4a;
stage 2.4c: stopping the stirring action and separate the residual liquid obtained at the end stage of 2.4b by any of commonly known filtration methods, is denoted as stream F, and the said Stream F being charged to a washings storage tank; and
said step 2.5 comprises the following stages:
stage 2.5a: charging said Stream A of step 2.1 and said Stream B of step 2.2, either individually or in any combination, to said second reaction vessel;
stage 2.5b: distillation of the mixture obtained at the end of stage 2.5a
stage 2.5c: stopping the distillation action and separating the amino compounds formed during the earlier steps is steam distilled.
6. A process as claimed in claim 5 further wherein
in stage 1.1a the quantity of the reaction medium used is denoted as QRM1.1 and is variable the range of 0% (w/w) to 40% (w/w) of QRMT used in this cycle;

wherein said QRMT is the total quantity of the reaction medium used in this cycle, said QRMT being determined such that the ratio, denoted as (Weight Ratio)RM, of the weight of said QRMT, WRM, to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle WN; the relationship between (Weight Ratio)RM, WRM, and WN being represented by the equation
(Weight Ratio)RM = WRM/ WN;
and wherein said (Weight Ration)RM is preferably in the range of 5 to 100, the more preferable range being 10 to 75, and;
in stage 1.1b the amount of acid charged is such that the pH of said start up reaction mixture is in the range between 1 to 9, and the temperature of the start-up mixture is in the range between 0 °C to 200 °C;
in stage 1.1c the mixture thus formed is agitated for a duration in the range of 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours, while maintaining the pH of the mixture during the agitation stage of stage 1.1c in the range between 1 to 9, preferably between 3 to 7, more preferably between 4 to 6, while maintaining the temperature of the mixture during the agitation stage of stage 1.1c in the range between 0 °C to 200 °C; and
in stage l.ld adding to said first reaction vessel, upon completion of the agitation stage of stage 1.1c, said reducing agent in a quantity denoted as QRA1.1, said QRA1.1 being variable in the range of 0% to 100% of QRAT;

wherein said QRAT is the total quantity of the reducing agent used in this cycle; said QRAT being determined such that the ratio, denoted as (Weight Ratio)RA, of the weight of said QRAT, WRA, to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle, WN; wherein the relationship between (Weight Ratio)RA, WRA, and WN is represented by the equation:
(Weight Ratio)RA = WRA/ WN ;
and wherein said (Weight Ratio)RA is preferably in the range of 0.25 to 25, the more preferable range being 0.5 to 2.5;
wherein said reducing agent is added either in its full required quantity, QRA1.1, or in batches, or continuously, or as any combination of these methods of addition, over a period of 0 minutes to 5 hours, preferably 0.5 hours to 2.5 hours; and wherein the pH of the mixture in said first reaction vessel at the time of addition of said reducing agent is between 1 to 9, preferably between 2 to 7 ;
in stage 1.2a reduction period is in the range of 0 to 25 hours;
in stage 1.2c the acid added is in a quantity to bring the pH value of the mixture thus formed within the range between 1 to 9, while maintaining the temperature of the mixture formed by addition the acid to said reduction mixture between 0 °C to 200 °C; and
in stage l.2d said QRA1 .2 is added either simultaneously with the R-NO2 or R-NO compound to be reduced in stage 1.2a, or after the addition of acid of stage 1.2c, thereby forming a reduction agent mixture; wherein said RA1.2 is added at a reduction time such that the pH of said reduction agent

mixture is in a range between 1 to 9, and such that the temperature of said reduction mixture is in the range between 0 °C to 200 °C;
wherein the quantity of QRA1.2, denoted as QR1.2, is such that said QR1.2 is the difference between QRT and QR1.1;
in stage 1.3a the quantity of the reaction medium used in step 1.3, denoted as QRM1.3, is variable in the range of 0% (w/w) to 40% (w/w) of QRMT;
in stage 1.3b the quantity of said neutralizing agent used, NA1.3, wherein the quantity if said neutralizing agent used, QNAT, is the total quantity of the neutralizing agent to be used in this cycle; said QNAT being determined such that the ratio, denoted as (Weight Ratio)NA, of the weight of said QNAT, WNA, to the weight of total amount of R-NO2 or R-NO to be reduced in that single cycle, WN; wherein the relationship between (Weight Ratio)NA, WNA, and WN is represented by the equation:
(Weight Ratio)NA = WNA/WN;
and wherein said (Weight Ratio)NA is preferably in the range of 0 to 2.5, the more preferable range being 0.05 to 0.25; and
wherein said neutralizing agent is added over a period in the range between 0 minutes to 5 hours, more preferably between 0.5 hours to 2.5 hours, at a temperature in the range between 0 °C to 200 °C, and at a pH in the range between 1 to 9, preferably 2 to 8;
wherein R-Cat or G-Cat is used as the preferred neutralizing agent;

in stage 1.3c the neutralization takes place at a temperature between 0 °C to 200 °C, at a pH between 1 to 9, preferably 2 to 8, carried out over a period between 0 hours to 10 hours,;
wherein the contents of said first reaction vessel during any or all stages of 1.3a to 1,3c are optionally stirred for any duration of the individual stages using said agitator rotating at a rate between 0 to 500 RPM;
in stage 1.4a the quantity of R-Cat or G-Cat being such that its weight ratio with R-NO2 or R-NO is in the range of a 0.05 wAv to 5 w/w, added at a time such that the pH of said isolation reaction mixture is in the range of 1 to 12,
in stage 1.4b the separation reaction mixture is added at a temperature between 0 0C and 200 °C, and at pH level between the range of 1 to 12; and
in stage 1.4c the separation mixture obtained at the end of stage 1.4b is maintained at a temperature between 0 °C and 200 °C, for a period in the range of 0 hours to 24 hours,;
in stage 2.1a the first settling reaction mixture is charged while maintaining the temperature of the mixture in the range between 0 °C and 200 °C, and the pH of the mixture in the range between 1 to 12, preferably between 4 to 11, and wherein the quantity of said first settling reaction mixture used, denoted as QRM2.1, IS variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle;

in stage 2. lb the temperature of the mixture in the range between 0 °C and 200 °C, and the pH of the mixture in the range between 1 to 12, and said first settling time is in the range between 1 minute to 10 hours;,
in stage 2.1c the first decanting temperature is in the range between 0 °C and 200 °C, a first decanting pH in the range between 1 to 9, and first decanting time in the range between 1 minute to 10 hours;
in stage 2.2a the second settling reaction mixture is added at a predetermined first stirring temperature and a predetermined first stirring pH at a predetermined first stirring time;
in stage 2.2b stirring and continuing to stir the mixture of stage 2.2a by maintaining the mixture at a predetermined first stirring continuation temperature, a predetermined first stirring continuation pH for a predetermined first stirring continuation time;
in stage 2.2c stopping the stirring action and allowing the mixture of stage 2.2 b to settle at a predetermined second settling pH, a predetermined second settling temperature for a predetermined second settling time; and
in stage 2.2d decanting the liquid layer collected at the end of stage 2.2c, the liquid layer denoted as Stream B, at a predetermined second decantation temperature, a predetermined second decantation pH and at a predetermined second decantation time; said Stream B being charged to step 2.5 of the same cycle or any of the following cycles;
wherein the values each of said first stirring temperature, said first stirring continuation temperature, and said second decantation temperature are in the range of 0°C and 200°C; the values of each of said first stirring pH, said first stirring continuation pH, and said second decantation pH are in

the range of I to 12; the values of each of said first stirring time, said first stirring continuation time, and said second decantation time are in the range of 5 minutes to 5 hours; and
wherein the quantity of the reaction medium used in step 2.2, denoted as QRM2.2 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle;
in stage 2.3a the third settling reaction mixture is added at a predetermined second stirring temperature and a predetermined second stirring pH at a predetermined second stirring time;
in stage 2.3b stirring and continuing to stir the mixture of stage 2.3 a by maintaining the mixture at a predetermined second stirring continuation temperature, a predetermined second stirring continuation pH for a predetermined second stirring continuation time;
stage 2.3c stopping the stirring action and allowing the mixture of stage 2.3 b to settle at a predetermined third settling pH, a predetermined third settling temperature for a predetermined third settling time; and
stage 2.3d decanting the liquid layer collected at the end of stage 2.3 c near the top of said reaction vessel, the liquid layer denoted as Stream E, at a predetermined third decantation temperature, a predetermined third decantation pH and at a predetermined third decantation time; said Stream E being charged to a washings storage tank;
wherein the values each of said second stirring temperature, said second stirring maintenance temperature, said third settling temperature, and said third decantation temperature are in the range of 0°C and 200°C; the values of each of said second stirring pH, said second stirring maintenance

pH, said third settling pH, and said third decantation pH are in the range of 1 to 12; the values of each of said second stirring time, said second stirring maintenance time, said third settling time, and said third decantation time are in the range of 5 minutes to 5 hours; and
wherein the quantity of the reaction medium used in step 2.3, denoted as QRM2.3 is variable in the range of 0% (w/w) to 60% (w/w) of QRMT used in this cycle;
in stage 2.4a the quantity of said first separation and washing reaction mixture, denoted as QRM2.4, is variable in the range of 0% (w/w) to 60% (w/w) of the QRMT used in this cycle.
in stage 2.4b stirring and continuing to stir the mixture of stage 2.4a at a predetermined stirring temperature in the range of 0°C and 200°C, a predetermined separation pH in the range of 1 to 12, and a predetermined separation time in the range of 5 minutes to 5 hours;
in stage 2.4c stopping the stirring action and separate the residual liquid obtained at the end stage of 2.4b by any of commonly known filtration methods, is denoted as stream F, and the said Stream F being charged to a washings storage tank
in stage 2.5b distillation of the mixture obtained at the end of stage 2.5a at a second separation temperature that is in the range between 0 °C and 200 °C, preferably in the range between 0 °C and 100 °C, a second distillation pH that is in the range between 1 to 12, preferably between 4 to 9, and for

a second separation time that is in the range between 5 minutes to 5 hours; and
in stage 2.5c slopping the distillation action and separating the amino compounds formed during the earlier steps is steam distilled at the period over which the temperature reduction is carries out is in the range between 5 minutes to 10 hours, more preferably between 30 minutes to 3 hours; and wherein the third separation temperature is in the range between 20°C to -20 °C.
7. A process as claimed in claim 6 wherein;
in stage 1.1b the pH of the start up reaction mixture is preferably between 4 to 6;
in stage 1.1c the agitation is preferably carried out between 0.5 hours to 2.5 hours, while maintaining the pH of the mixture during the agitation stage of stage 1.1c is preferably between 4 to 6;
in stage said said reducing agent is added over a period preferably between 0.5 hours to 2.5 hours; and wherein the pH of the mixture at the time of addition of said reducing agent is preferably between 2 to 7;
in stage 1.2c the reduction mixture has a pH preferably between 4 to 6; and
in stage 1.2d the reducing agent is added at a reduction time such that the pH of said reduction agent mixture is in a range preferably between 4 to 6;
in stage 1.3a optionally adding a suitable reaction medium, denoted as neutralization RM, in a suitable quantity to said reaction vessel, wherein

quantity of the reaction medium used in step 1.3, denoted as QRM1.3, is variable in the range of 0% (w/w) to 40% (w/w) of QRMT;
in stage 1.3b said neutralizing agent is added over a period preferably between 0.5 hours to 2.5 hours, at a pH preferably between 2 to 8;
in stage 1.3c the neutralization takes place at a pH preferably between 2 to 8, said neutralization being carried out over a period preferably in the range of 30 minutes to 5 hours;
in stage 1.4a the activated carbon is charged in weight ratio with R-N02 or R-NO is in the preferable range of 0.5 w/w to 2.5 w/w, at a time such that the pH of said purification reaction mixture is in the range preferably between 4 to 11;
in stage 1.4b the separation reaction medium is added at pH level preferably between 4 to 11; and
in stage 1.4c the purification mixture is maintained at a temperature preferably between 0°C to 100°C, for a period preferably in the range of 30 minutes to 5 hours;
in stage 2.1b the reaction mixture obtained at the end of stage 2.1b is allowed to settle down at the pH preferably between 4 to 11 wherein said first settling time is preferably between 30 minutes to 3 hours;
in stage 2.1c said first decanting pH is preferably between 4 to 11 and first decanting time preferably between 30 minutes to 3 hours;
in stage 2.2b the values each of said first stirring temperature, said first stirring continuation temperature, and said second decantation temperature

respectively are preferably between 0 °C to 100 °C; the values of each of said first stirring pH, said first stirring continuation pH, and said second decantation pH are in the range preferably between 4 to 11; the values of each of said first stirring time, said first stirring continuation time, and said second decantation time are preferably between 30 minutes to 3 hours; and
in stage 2.3d the values each of said second stirring temperature, said second stirring maintenance temperature, said third settling temperature, and said third decantation temperature are preferably between 0 °C to 100 °C; the values of each of said second stirring pH, said second stirring maintenance pH, said third settling pH, and said third decantation pH are in the range preferably between 4 to 11; the values of each of said second stirring time, said second stirring maintenance time, said third settling time, and said third decantation time are in the range of preferably 30 minutes to 3 hours; and
in stage 2.4b the separation pH is in the range preferably between 4 to 11, and a predetermined separation time in the range preferably 30 minutes to 3 hours;
in stage 2.5b stirring the mixture obtained at the end of stage 2.5 a at a steam distillation pH that is in the range preferably between 4 to 9, and for a steam distillation time that is in the range between preferably 30 minutes to 3 hours; and
in stage 2.5c the period over which the temperature steam distillation is carried out is in the range preferably between 30 minutes to 3 hours; and wherein the steam distillation temperature is in the range preferably between 0 °C to 100 °C.

8. A process as claimed in any of claims 2 to 5, wherein said first suitable acid and said second suitable acid are sulphuric acid.
9. A process as claimed in any of claims 2 to 6, wherein the reducing agents of steps 1.1 and 1.2, namely said RA1.1 and QRA1.2, are G-Cat, R - Cat or any other suitable reduction agent.
10. A sustainable chemical process of nitro-compounds, R-NO2, or nitroso compounds, R-NO, into corresponding amino - compounds, R-NH2, as claimed in any of claims 2 to 9, wherein the neutralisation agent of step 1.3 is any proprietary neutralisation agent.
11. A process as claimed in any of claims 2 to 10, wherein the nitro compound to be reduced is added to the step 1.2 in its entire quantity or in batches of any size at any interval.
12. A process as claimed in any of claims 2 to 12, wherein said salt of iron with inorganic or organic acids, preferably selected from a group of salts comprising ferrous sulphate, ferrous chloride, ferrous ammonium sulphate, ferrous oxalate, ferrous citrate, or any combination thereof, or a salt selected from a group comprising ammonium chloride, ammonium sulphate, other such salts, or any combination thereof, is used in place of said first suitable acid of step 1.1b.
13. A process as claimed in any of claims 2 to 12, wherein said reducing agent of stage 1,3b is selected from a group comprising hydroxides, carbonates, or bicarbonates of alkali metals, either individually or in any combination thereof; said hydroxides preferably being sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide; said carbonates preferably being sodium carbonate, potassium carbonate, calcium carbonate, or lithium carbonate; said bicarbonates preferably being sodium bicarbonate, potassium

bicarbonate, lithium bicarbonate; and wherein said reducing agent of step 1 .1d comprises multifunctional, chemical reduction formulation selected from a group comprising fine iron powder, electrolyte salt of various metals such as sodium, magnesium, calcium, iron, nickel, cobalt, tin, zinc, titanium, copper, manganese, and any other metals with multiple valancies, customized grade of activated carbon, and specialty additives like polyelectrolyte's, anti foaming agents, dispersing agents, anti oxidants, emulsifying agents, mass transfer enhancing agents, anti caking agents, UV stabilizers, solubilising agents, preferably fine iron powder.
14. A process as claimed in any of claims 2 to 12, wherein the neutralising agents
are selected from a group comprising agent in the form of hydroxides of alkali metals like sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, carbonates or bicarbonates of alkali metals like sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, lithium carbonate, other such salts or any combination thereof.
15. A process as claimed in any of claims 1-2 and 5-14 wherein said number of
cycles is greater than 100.