FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patent Rules, 2003
Complete Specification
__ (See section 10 and rule 13)
GREEN CONVERSION OF AROMATIC AMINO COMPOUNDS INTO CORRESPONDING AROMATIC HYDROXY COMPOUNDS WITH INHERENT INFINITE RECYCLE OF PROCESS MOTHER LIQUOR Newreka Chemicals Private Limited, Rang Ashish, 2 Dreamland CHS, Opp Diamond Garden, Chembur, Mumbai 400 071, Maharashtra State, An Indian company registered under the Companies Act, 1956.
Mr. Padia, Bhadresh K, Rang Ashish, 2 Dreamland CHS, Opp Diamond Garden, Chembur, Mumbai 400 071, Maharashtra State, India An Indian National.
Mr. Mehta, Nitesh H, 4 Shri Sanman, Juhu Varsova Link Road, Andheri (W), Mumbai 400 053, Maharashtra State, India An Indian National.
The following specification particularly describes the invention and the manner in
which it is to be performed:


GREEN CONVERSION OF AROMATIC AMINO COMPOUNDS INTO CORRESPONDING AROMATIC HYDROXY COMPOUNDS WITH INHERENT INFINITE RECYCLE OF PROCESS MOTHER LIQUOR
Field of Invention:
This invention relates to a general process for conversion of aromatic amino compounds into the corresponding aromatic hydroxy compounds with a large number of recycles of reaction medium as well as all other liquid streams.
Background of Invention:
Conversion of aromatic amino compounds into corresponding aromatic hydroxyl compounds find applications in the field of various groups of chemical including pharmaceuticals, dyes, agrochemicals, specialty chemicals, fine chemicals.
One of the important hydroxy compounds is 2-Hydroxy-4-methylpyridine [13466-41-6]; a building block for an important and currently used 'ANTI-AIDS' drug 'Nevirapine' [129618-40-2]. Some of the other compounds are 3-Hydroxy-6-methylpyridine [1121-78-4], 2-Hydroxy-6-methylpyridine [3279-76-3], 3-(4-Hydroxyphenyl) propionitrile [17362-17-3], m-Hydroxyacetophenone [121-71-1], 3-Fluorophenol [372-20-3], 2-4,4-trichloro-2-amino diphenyl ether (TADE) [56966-52-0] intermediate for Antibacterial Triclosan [3380-34-5] used in manufacturing soaps and detergents.
There are several drawbacks of existing methods used for conversion of aromatic amino compounds into corresponding aromatic hydroxyl compounds. These methods generate liquid waste which is difficult to recycle. In most of the existing methods organic solvents extraction is used for product isolation may be in order to get maximum yield in hand. Use of organic solvents poses safety related

problems. Secondly Caustic Soda Lye for salting purpose and Cupric Sulphate are also used in product isolation and to prevent accumulation of impurities in product yields - rise in salt content in product and complex impurities formed by cupric sulphate and impurities generated in the reaction. This leads to low purity product and low yields in hands. Generation of highly acidic effluent needs a large facility for effluent treatment and disposal wastes. These factors impose location related constraints making it mandatory for these processes to be carried out only in designated areas. In general existing processes are non-green that harms the environment to a large extent, which has become the major global concern in today's scenario.
Hence there is a need for providing a process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds with inherent large number of recycles of reaction medium as well as all other liquid streams thereby avoiding above mentioned disadvantages and drawbacks and providing an environmentally sustainable and economical recycling process.
Objects and Advantages of Invention:
The inventors have developed a novel process for conversion of aromatic amino compounds into the corresponding aromatic hydroxy compounds with a large number of recycles of reaction medium along with all other liquid streams with no use of organic solvents for product isolation.
In order to overcome the various serious drawbacks of the existing methods, either general alkali or customized Proprietary Catalytic Formulation NDHF, developed by Newreka Chemicals Pvt. Ltd. can be used which enables us to recycle reaction medium as well as all other liquid waste stream completely in the reaction and in the purification sequence. NDHF is a multifunctional formulation comprising of hydroxides of calcium or alkali metals like sodium, potassium, customized grade

of activated carbon, filter aid and decolorizing agent containing silicon compounds, alumina, zirconia etc. with a range of pore sizes in appropriate composition. Use of NDHF in the process of the present invention prevents localized temperature shock; minimizes high PH shock due to Caustic soda lye which causes side reactions and generates impurities. NDHF prevent PH shock in recycle of reaction medium and all other liquid streams.
An object of the process of the present invention is to provide an environmentally friendly (green) process that overcomes the problem of generation of large quantities of liquid wastes resulting from the conventional processes.
Another object of the present invention is to provide a process, wherein side reactions leading to side products formation are minimized which results in purer product formation.
A further object of the present invention is to provide a process wherein side products formation is minimized, thereby reducing the possibility of build-up of side products in reaction medium as well as all other liquid streams to a large extent and consequently making it possible to have a large number of reaction medium as well as all other liquid streams recycles.
A still further object of the present invention is to provide a process wherein the product is isolated and purified so that the solid spent formed is not contaminated with organic compounds.
Yet another object of the present invention is to provide a process that does not require any elaborate effluent treatment facility or a substantial solid waste disposal facility and does not have major location constraints.

Yet another object of the present invention is to provide a process whereby the end product, which is the aromatic hydroxyl compound, have fewer impurities than produced by conventional processes.
In this invention the acidic waste stream generated after isolation of the product is treated with NDHF developed in-house or any other customized Proprietary Catalytic Formulation or any other neutralizing agent. This treatment completely converts the acidic waste stream into a useful stream, which is recycled totally in the reaction sequence as well as in the purification sequence.
Summary of the invention:
The present invention describes a green process for the conversion of aromatic amines into corresponding aromatic hydroxyl compounds that produces greener aromatic hydroxyl compounds in good yields in hand with a large number of recycles of reaction medium as well as all the liquid streams generated with capacity of scale-up to any level and has wide scope since it can be applied to many molecules. This method creates a closed fresh reaction medium loop. The major portion of the waste stream generated is recycled completely in the reaction sequence as well as in the purification sequence minimizing liquid waste in our process.
The purification crude aromatic hydroxyl compound so formed in reaction sequence can be done in the (methanol) solvent or water or a combination thereof used in the reaction.
Brief Description of Figures:
Figure 1 shows green reaction sequence of the present invention with a large number of recycles of reaction medium as well as all other liquid streams,

Figure 2 shows green purification sequence of the present invention with a large number of recycles of reaction medium as well as all other liquid streams, Figure 3 shows the complete green sequence of the present invention with a large number of recycles of reaction medium as well as all other liquid streams. Figure 4 shows generation and fate of all reaction medium as well as all other liquid streams in both the reaction as well as purification sequences of the present invention.
Detailed description of the invention:
The process of the present invention comprises combination of two sequences. The process is performed in closed loop cycles. The first sequence is the green reaction sequence of the present invention and the second sequence is the green purification sequence of the present invention. The green reaction sequence with a large number of recycles of reaction medium as well as all other liquid streams is as shown in Figure 1. The purification sequence with a large number of recycles of reaction medium as well as all other liquid streams is as shown in Figure 2. The process of the present invention, which comprises first and second sequences is as shown in Figure 3. Generation and fate of reaction medium as well as all other liquid streams from all the steps in both the sequences of the present invention is as shown in Figure 4.
The terminology used in this invention is explained as follows,
• Reaction medium (RM) Reaction medium is the solvent or fresh reaction medium or a combination thereof used in the reaction and generated after performing a particular step. Reaction medium has been used as the RM at various stages of the process of the invention in its cycles following the first cycle.
• Fresh reaction medium (FRM) is fresh reaction medium or fresh solvent or a combination thereof used in the reaction,

• Solvent is any suitable solution that is fresh reaction medium miscible, fresh reaction medium immiscible, aromatic, and aliphatic or mixture thereof.
• Fresh Reaction Medium factor (FRMF) is the ratio of the weight of fresh reaction medium (FRM) with the dry weight of Ar-NH2 when used in the green reaction sequence, or with the dry weight of Ar-OH in case of the purification sequence
• Dilution medium factor (DMF) is the ratio of weight of the dilution medium (DM) with the dry weight of Ar-NH2 when used in the green reaction sequence, or with the dry weight of crude Ar-OH in case of the purification sequence
• Reaction medium factor (RMF) is the ratio of the weight of the reaction medium (RM) with the dry weight of Ar-NH2 when used in the green reaction sequence, or with the dry weight of crude Ar-OH in case of the purification sequence
• Washing medium factor (WMF) is the ratio of the weight of the washing medium (WM) with the dry weight of Ar-NH2 when used in the green reaction sequence, or with the dry weight of crude Ar-OH in case of the purification sequence
• Dissolution medium factor (DSMF) ) is the ratio of the weight of the dissolution medium with the dry weight of Ar-NH2 when used in the green reaction sequence, or with the dry weight of crude Ar-OH in case of the purification sequence
• Steady state of reaction medium is the composition of the reaction medium after initial recycles. This composition remains almost unchanged during subsequent recycles.
• Bleed is bleeding of part of reaction medium to take out material causing changes in the steady state composition of mother liquor.
• Cooling curve (CC) is profile of temperature verses time.

The process of the present invention uses a proprietary formulation NDHF 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 valance 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).
NDHF 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).
NDHF 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 diazotization followed by hydrolysis of AR-NH2 into corresponding AR-OH with inherent infinite recycle of all liquid streams generated in the same.
The chemical process of the present invention basically comprises inherent infinite number of recycles of processing the mother liquor and all liquid 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 purification 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.
Detailed description of the invention:
The generation and fate of various liquid streams as shown in Figure 4 is described as follows for a batch process method. The process of the present invention is also applicable with the continuous or semicontinuous recycling processes.
In the very first batch fresh reaction medium is reaction medium in start-up (Step 1.1), for dilution (Step 1.3), in purification (Step 2.1) and for washings (Steps 1.4 & 1.6). In subsequent batches fresh reaction medium is replaced by the liquid streams generated in the first batch.
This means that fresh reaction medium is used only in the first batch, this fresh reaction medium subsequently gets recycled in further batches in reaction and purification sequences.
Stream 1A is generated after isolation of the crude Ar-OH. Stream 1A is divided into two parts, stream IB & stream 1C. Stream IB is stored in a start-up mother liquor storage tank from which it is recycled into the start-up (Step 1.1). Stream 1C is treated with NDHF (Step 1.5). stream ID, which is taken from the storage tank containing stream IB, is used for washing of NDHF spent (Step 1.6).

Washings generated in Step 1.4 are stored in a washings storage tank. Stream IF generated after filtration of NDHF spent (Step 1.6) is stored in a hot mother liquor storage tank from which it is recycled into the dilution step (Step 1.3). Stream \G generated after washing of NDHF spent (Step 1.6) is used for neutralization (Step 1.7) along with stream IE generated in washing of crude Ar-OH (Step 1.4). Stream 1H generated after filtration of recovered crude Ar-OH (Step 1.8) goes to salt pan for evaporation. Stream 1H is the bleed of the recycle loop. Volume of stream ID, IE and 1G are very small as compared to other streams which are recycled back.
Stream 2A is generated after isolation of pure Ar-OH is divided into two streams; stream 2B is stored in the storage tank from which it is recycled into dissolution (Step 2.1) and 2C is used for washing of crude Ar-OH (Step 1.4).
Some quantity of fresh reaction medium is used as make-up fresh reaction medium in various steps to compensate for the bleed.
Details of the steps involved in the process are described below, with reference to figures 1, 2, 3 and 4.
Green reaction sequence of the present invention:
Step 1.1 - Start-up: As shown in figure 1, at the start of the process, in the first batch, fresh reaction medium (replaced by stream ID taken from the start-up mother liquor storage tank in subsequent batches) is charged in suitable quantities as per predetermined fresh reaction medium factor into a jacketed reactor with agitator and other known attachments known to a person skilled in the art. The weight factor of fresh reaction medium is in the range of l(w/w) to 25(w/w), the preferable range being l(w/w) to 15(w/w); more preferable range being l(w/w) to 10(w/w) with respect to the total quantity of Ar-NH2 (i.e. batch size).

Optionally, a suitable acid, or a salt of metal with inorganic or organic acids is added in suitable quantity and suitable form while maintaining predetermined temperature of the reaction medium in the reaction vessel.
In the preferred embodiment of the invention, Sulfuric acid is added, maintaining temperature in a range of 0°C to 35°C, preferable range being 0°C to 20°C; more preferable range being 0°C to 10°C, with agitation continued for a predetermined time in the range of 0 minutes to 5 hours, preferably in the range of 0.5 hours to 3 hours and more preferably between 0.5 hours to 2.5 hours. The pH of the solution is maintained throughout this step at a predetermined level. The pH range of the solution is in the range of 1 to 9, preferably in the range of 2 to 7, more preferable range being 2 to 4.
Step 1.2 - Reaction: The quantity (X) of Ar-NH2 compound to be diazotized is added to the reaction vessel either in its full amount or in any number of lots followed by addition of a of solution of NaN02. The quantity (Y) of NaN02 to be used to make a NaN02 solution is calculated as 10-20% excess with respect to theoretical quantity (X!) of the NaN02 required to complete the reaction, and is expressed as per follows -
Quantity of NaN02:

11

The solution of NaN02 is made by dissolving 'Y' quantity of NaN02 in 0.5(w/w) to 2(w/w) quantity of fresh reaction medium with respect to quantity of NaN02. This solution in suitable quantities is charged to the reaction mass either in its full amount or in any number of lots.
The Ar-NH2 compound and NaN02 solution is added over a period of 0 to 25 hours, at a suitable interval of time that depends on the molecule to be diazotized in the temperature range of 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C with agitation continued for period in the range of 1 hours to 25 hours, preferable range being 1 hour to 20 hours; more preferable range being 1 hour to 12 hours, and maintained in the pH range of 1 to 9, preferably in the range of 2 to 7, more preferable range being 2 to 4.
Stirring is continued at the predetermined temperature and predetermined pH till reaction is complete as shown by absence of Ar-NH2 The distinct advantage of these conditions is that the crude Ar-OH generated in this step contains less number of impurities, in very low quantities avoiding building-up of impurities in reaction medium as well as all other liquid streams making a large number of recycles possible.
Step 1.3 - Isolation by dilution: After completion of the reaction in Step 1.2, in the first batch, a quantity of fresh reaction medium (replaced by stream IF, taken from the hot mother liquor storage tank in subsequent batches) calculated using a fresh reaction medium factor in the range of 0(w/w) to 30(w/w), preferable range being l(w/w) to 20(w/w) and more preferable range being l(w/w) to 10(w/w) is charged into total mass obtained from Step 1.2 in the reactor and total mass is maintained at predetermined temperature in the range of 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C and for a agitation time in the rage of 0 hours to 10 hours, preferable range being 30

minutes to 5 hours, more preferable 30 minutes to 2 hours. Thediluted mass is used for isolation of crude Ar-NH2 by Alteration.
In another embodiment of the present invention, the isolation of crude, any other method of product isolation, such as liquid-liquid isolation may be used.
Total mass in the rector is then cooled to predetermined temperature in the preferable range being 0°C to 35°C, PH range being 1 to 9, preferably in the range of 2 to 7, more preferable range being 2 to 4 and maintained for 0 hours to 8 hours, preferable range being 30 minutes to 4 hours following a predetermined temperature curve.
Step 1.4 - Filtration & Washing: Total mass from Step 1.3 is filtered by known methods by maintaining the temperature of the filtered mass in the range of 0°C to 100°C, preferable range being 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C. Filtered mass is washed with a washing medium, in the temperature range of 0°C to 100°C, preferable range being 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C. In the first batch, washing medium is fresh reaction medium (replaced by stream 2C in subsequent batches) calculated by a reaction medium factor in the range from 0(w/w) to 5(w/w), preferable range being 0.1(w/w) to 2.0(w/w) till the washings show pH in the range from 1 to 9, preferable range being 2 to 7, more preferable range being 2 to 4.
This washing stream (IE) is stored. The solids obtained contain crude Ar-OH. The benefit of this washing operation is that it removes acid contamination of the crude Ar-OH.
Step 1.5 - NDHF Treatment: To the filtrate from the Step 1.4, NDHFa Diazotization-Hydrolysis, a treatment agent, is charged. The quantity of the

treatment agent is calculated by a factor of 0% (w/w) to 1 %( w/w), preferable range being 0.05 to 0.5 %(w/w) the reaction medium to be treated. The temperature of the mixture is maintained in the range from 0°C to 100°C, preferably 40°C to 80°C, more preferably 60°C to 70°C. The time of charging the treatment agent is in the range of 0 hours to 5 hours, preferable range being 30 minutes to 2 hours maintaining the PH of the mixture in the range from 1 to 9, preferable range being 2 to 7 and more preferable range being 4 to 6. Total mass charged with the treatment agent is maintained at a temperature in the range of 0°C to 100°C, preferably 40°C to 80°C, more preferably 60°C to 70°C for 0 hours to 5 hours, preferable range being 30 minutes to 2 houfs
The benefit of this operation is that it helps in removing certain quantity of salt generated in the reaction, and a certain quantity of acid along with the certain quantity of imparities. This bleed is Vitai for the large number of letyttes of reaction medium as well as all other liquid streams.
Step 1.6 - Filtration & Washing: Total mass form Step 1.5 is filtered by known methods in the temperature temperature range of 0°C to 100°C, preferable range being 40°C to 80°C, more preferable range being 60°C to 70°C, and washed with stream ID, taken from start-up mother liquor storage tank in suitable quantity. The quantity of stream ID to be used for washing is determined by a washing factor that is in the range of 0 (w/w) to 5 (w/w), preferable range being in the range of 0.5 (w/w) to 2 (w/w) with respect to Ar-NH2 input. The washing is carried out at a temperature in the range of 0°C to 100°C, preferable range being 40°C to 80°C, more preferable range being 60°C to 70°C and at a pH in the range from 1 to 9, preferable range being 2 to 7 and more preferable range being 4 to 6.
The filtrate (stream IF) is stored and used in the dilution step (Step 1.3) in the subsequent batches. Washings from the present (stream 1G) are charged to neutralisation step (Step 1.7). The advantages of the washing of the cake are that it

removes most of Ar-OH trapped in cake giving better recovery of Ar-OH, and that this operation renders the spent NDHF more environment friendly.
Step 1.7 - Neutralisation: The washing stream (stream 1G) from Step 1.6 and the washing stream (stream IE) from the Step 1.4, collected from the washings storage tank, are charged together or separately in any sequence in suitable quantities in this step. NDHF is charged in a quantity calculated using a weight factor in the range of 0% (w/w) to 2% (w/w) with respect to the input weigh of Ar-NH2, in the temperature range of 0°C to 100°C, preferable range being 40° to 70°C, till the pH of the mixture is in the range of 1 to 9 , preferable range being 5 to 8, more preferable range being 5.5 to 7.5.
Total mass is maintained at a temperature in the range of 0°C to 100°C, preferable range being 40° to 70°C for 0 hours ti 2 hours; preferable range being 30 minutes to 1 hour. The advantage of this operation is that it precipitates practically all of the Ar-OH from these streams leading to practically complete recovery of Ar-OH which in turn leads to greener process.
Step 1.8 - Filtration: Total mass from the above step (Step 1.7) is filtered by known methods by maintaining the temperature of the filtrate in the range from 0°C to 100°C, preferable range being 40°C to 70°C. The spent cake is then washed with a washing medium with a washing medium factor in the range of 0 (w/w) to 5 (w/w), preferable range being in the range of 0.5 (w/w) to 2 (w/w) till pH range of 1 to 9, preferable range being 5 to 8, more preferable range being 5.5 to 7.5 is obtained. In the preferred embodiment, the washing medium is the FRM. The solid obtained contains recovered crude Ar-OH. The benefit of this operation is that it gives better recovery of Ar-OH and renders the filtrate environmentally friendly.

Step 1.9 - Evaporation: The filtrate stream (stream 1H) generated in the Step 1.8 is evaporated by natural means or by predetermined methodology in the natural temperature range of 20°C to 50°C. The advantage is that this operation converts stream 1H into pure fresh reaction medium vapour and salt which is environment friendly since it contains very low level of organics.
It has been observed that the pH of the spent is in the range of 3 to 9, typically the pH range being 6.5 to 7.5. The moisture content is in the range of 5% to 50%, typical range being 15% to 25%. The benefit is that this spent does not contain any substantial quantity of Ar-OH and other organics rendering it greener and does not require substantial disposal facility.
Green purification sequence of the present invention:
Step 2.1 - Dissolution: As shown in figure 2, at the start of the process, in the first batch, fresh reaction medium or fresh solvent or a combination thereof is used in the reaction (replaced by stream 2B in subsequent batches).
In the preferred embodiment of the present invention the combination of fresh reaction medium and solvent in the weight ratio of 75:25 respectively, is charged. The quantity of the combined solution of FRM and solvent is obtained using a weight factor in the range of 0(w/w) to 100(w/w), preferable range being 10(w/w) to 75(w/w), more preferable range being 10(w/w) to 50(w/w) with respect to crude Ar-OH to be purified. This quantity is charged into a jacketed reactor with agitator and other known attachments.
A quantity of crude Ar-OH obtained using a weight factor in the range of 4% (w/w) to 8% (w/w) with respect to total reaction medium depending on solubility of Ar-OH in the medium, is charged with dispersion and then dissolution. For example, for a reaction vessel with an operating volume of 450 litres, 30kg to

45kg of dry Ar-OH is added in a batch. Dry Ar-OH crystals are dispersed in a dispersion medium (FRM is used a dispersion medium), the weight of which is approximately twice the weight of the dry crystals. Dispersion is done at a temperature in the range of 0°C to 100°C, preferable range being 25°C to 75°C, with the mixture being agitated throughout the dispersion stage, the time of dispersion being in the range from 0 hours to 10 hours, preferable range being 30 minutes to 2 hours.
The dispersion stage is followed by dissolution, the dissolution temperature being in the range of 0°C to 75°C, preferable range being 25°C to 75°C. Dissolution time in the range of 0 hours to 5 hours, preferable range being 30 minutes to 2 hours.
After ensuring complete dissolution of Ar-OH in reaction medium, NDHF in the range of 0% (w/w) to 25% (w/w), preferable range being 0.5%(w/w) to 5%(w/w) is charged to adjust the pH of the mixture to bring it in the range from 1 to 9, preferably in the range 5.5 to 7.5, holding the temperature of the at the temperature in the range of 0°C to 100°C, more preferable range being 25°C to 75°C.
Activated carbon is charged in the range of 0 %(w/w) to 8%(w/w), preferable range being 0.5%(w/w) to 5% (w/w).
All the reactants in suitable quantities are charged in predetermined sequence by maintaining a predetermined pH, during predetermined time. Total mass is maintained at a temperature preferably in the range of 0°C to 100°C, more preferable range being 25°C to 75°C, for a duration in the range from 0 hours to 5 hours, preferable range being 30 minutes to 2 hours, under agitation.

The benefit of this step that it helps in removing impurities and any residual acidity from Ar-OH and reaction medium as well as other liquid streams which gives purer product and makes a large number of recycles of reaction medium as well as all other liquid streams possible002E
Step 2.2 -Filtration: Total mass in the above step (Step 2.1) is filtered by known methods in the preferable temperature range of 0°C to 100°C, more preferable range being 25°C to 95°C, without agitation, in the range of time from 0 hours to 10 hours, preferable range being 30 minutes to 5 hours maintaining the PH in the range of lto 9, preferably in the range 5.5 to 7.5 method.
The benefit of this operation is that it removes practically all Ar-OH adsorbed on the spent solids rendering the spent solids greener.
Step 2.3 - Crystallisation: Total filtrate obtained in Step 2.2 is charged into a jacketed reactor equipped with an agitator and other known attachments. Seed crystals of pure Ar-OH are added by maintaining the temperature of the filtrate in the range of 0°C to 100°C, preferable range being 60°C to 80°C, more preferable range being 55°C to 65°C. The quantity of the seed crystals added is calculated such that it is in the range from 0 %w/w to 10%w/w with respect to the input crude Ar-OH, preferable range being 0.5%w/w to 8%w/w, more preferable range being !%w/w to 5%w/w.
Seeding of pure Ar-OH is carried out in time range of 0 hours to 2 hours, preferable range being 15 minutes to lhour and maintained the PH in the range of 5to 8, preferably in the range 5.5 to 7.5.
Temperature is reduced to a level in a range of 0"C to 50°C, preferably 5°C to 25°C with maintaining the temperature for the time range of 0 hours to 24 hours, preferable range of 2 hours to 8 hours.

The advantage of this operation is that it generates purer, crystalline Ar-OH in good yield.
Step 2.4 -Filtration & Washings: Total mass from Step 2.3 is then filtered by known methods in the temperature range of 0°C to 50°C, preferably 5°C to 25°C and washed with fresh reaction medium. The quantity of the FRM used for washing is in the range from 0 % w/w to 100 % w/w of input Ar-OH, preferable range being 10%w/w to 60%w/w. The pH of the pure Ar-OH is maintained in the range from 5 to 8, preferably in the range 5.5 to 7.5.
Filtrate and washings together (stream 2A) is then stored, one part from which (stream 2B) in suitable quantity is recycled into dissolution step (Step 2.1) and other part (stream 2C) in suitable quantity is used for washing in Step 1.4 of the next cycles of the process of the invention.
The distinct advantage of this operation is the generation of purified and crystalline Ar-OH containing very small quantity of trapped reaction medium, which results in the environment friendly Ar-OH.
Step 2.5 - Drying: Ar-OH obtained in Step 2.4 is dried by known method at a temperature in the range of 0°C to 100°C, preferable range being 50°C to 70°C for a time in the range of 0 hour to 24 hours, preferable range being 1 hour to 10 hours following a predetermined temperature curve. The benefit of this operation is that it generates Ar-OH containing predetermined moisture content.
Step 2.6 - Pulverising: Dry Ar-OH obtained from Step 2.5 is pulverised by known method.
The benefit of this operation is that it generates Ar-OH with predetermined particle sizes.

Step 2.7 - Packaging: Ar-OH from Step 2.6 is packed in suitable material. The benefit of this operation is that it helps to maintain Ar-OH as per the required specifications till it is used further. Standard Packaging size is in the range of 1kg, 5kg and 25kg as per requirement.
The solid spent generated in this purification sequence of the present invention is crystalline and non-sticky in nature. Color of the spent ranges from gray to jet-black, typically the color is black. The pH of the spent is in the range of 3 to 9, typically the pH range being 6.5 to 7.5. The moisture content is in the range of 5% to 50%, typical range being 15% to 25%. The benefit is that this spent does not contain any substantial quantity of Ar-OH and other organics rendering it greener and does not require substantial disposal facility.
The combined process of the reaction sequence and purification sequence is shown in figure 3. Input from appropriate stages of the reaction sequence is sent into step 2.1 of the purification sequence. The combined sequence is run in a complete loop with no liquid effluent generated as the result of the combined process.
Though this invention refers to primary aromatic amines which melt above room temperature and have fresh reaction medium solubility less than 100%, same can be applied to aromatic amines which are liquids as well as to aromatic amines which are fresh reaction medium soluble.
The process of the present invention works with any equipment suitable for conversion reactions such as those described herein, with a ny filtration techniques, and filter types.

In another embodiment of the present invention, the sodium nitrite (NaN02) is substituted by nitrites of any of the group comprising calcium, magnesium, potassium, or ammonia, or any combination thereof, or the nitrous acid (HN02)
In yet another embodiment of the present invention, any weak alkali is used in place of the NDHF agent.
In a still further embodiment of the present invention, the sulfuric acid, or any other acid or salt that is used in the reaction, may be in any form such as solid or liquid, or any other form.
Following surprising advantages are observed by the inventors as a result of the process of the present invention:
1. It is an environmentally friendly (green) process that overcomes the problem of generation of large quantities of liquid wastes resulting from the conventional processes.
2. Side reactions leading to side products formation is substantially reduced which results in purer and greener product formation.
3. Since side products are formed to a very small extent, the possibility of buildup of side products in reaction medium as well as all other liquid streams during recycles is very low. This fact advantageously makes possible a large number of recycles of reaction medium as well as all other liquid streams in our process.
4. The product isolation and purification disclosed herein makes sure that the solid spent formed in the process of the present invention are not contaminated or contaminated to a very low extent with organic compounds and thus are green in nature. Consequently, the process described herein does not require any elaborate effluent treatment facility or substantial solid waste disposal facility and does not

have any major location constraints unlike existing processes. This is a further advantage over the conventional processes.
5. The method disclosed herein not only is green but the aromatic hydroxy
compounds produced at the end of the process are also greener owing to the fact
that they have fewer impurities.
6. In this invention the acidic waste stream generated after isolation of the product
is treated with NDHF developed in-house or any other customized Proprietary
Catalytic Formulation or any other neutralizing agent. This treatment completely
converts the acidic waste stream into a useful stream, which is recycled in the
reaction itself. Similarly use of NDHF developed in-house or any other
customized Proprietary Catalytic Formulation or any other neutralizing agent in
the purification sequence makes a large number recycles of reaction medium as
well as all other liquid streams possible.
1. In this invention fresh reaction medium followed by subsequent aqueous streams are used as solvent throughout making this process greener.
7. In this invention atmospheric pressure is used throughout making it greener and
safer and hence this process does not require special safety measures.
8. Temperature range used is milder leading to low energy consumption.
9. This invention relates to a process which uses fresh reaction medium as
reaction media, pressure required is atmospheric and temperatures used are milder
making this process green and safe.
10. A large number of recycle of fresh reaction medium used makes this process
more economical since a large number of recycles results in almost theoretical
yield of Ar-OH.

11. This process can be applied to conversion of any primary Ar-NH2 into corresponding Ar-OH.
Examples:
The following set of examples shows the recyclability of the green reaction sequence described in the process of the present invention.
Fresh cycle: In a 2 - liter -4 necks round bottom flask equipped with stirrer, thermometer, and addition port arranged in suitable heating/cooling system was charged 256.0 ml water, and 90.7lgm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta ammo acetophenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c. Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5 gm cupric sulphate in 50.0 ml water & maintained for 3 hours. Charged 400.0ml water for dilution of the reaction mass. Total reaction mass was heated to 70°c & charged 0.5gm decolorizing agent & maintained for 60min. Further it is cooled to 50°c & charged 0.5gm decolorizing agent again. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washed with 50.0 ml of water to get on drying 42.0gm of brown -Meta hydroxyacetophenone with M.P.-95°c. Mother liquor is stored for recycle after treatment.
Fifth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 4th recycle batch was charged, and 70.68gm sulphuric acid at room temperature. Diluted sulphuric acid solution chilled was to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml

sodium nitrite solution (NaNo2) below 5°c. Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged the solution of 2.5gm cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 800.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged 0.5gm decolorizing agent & maintained for 60min. Further it is cooled to 50°c & charged 0.5gm decolorizing agent. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 17.0gm of dark brown -Meta hydroxy acetophenone with M.P.- 90°c. Mother liquor is stored for recycle after treatment.
Fifteenth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 14 recycle batch was charged, and 65.63gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c. Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 800.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.Ogm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 48.0gm of brown -Meta hydroxy acetophenone with M.P.- 92°c. Mother liquor is stored for recycle after treatment.
Twentieth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 19th recycle batch was charged, and 66.55gm sulphuric acid

at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 800.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.0gm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2~l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 45.0gm of brown -Meta hydroxy acetophenone with M.P.- 93°c. Mother liquor is stored for recycle after treatment.
Thirtieth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 29th recycle batch was charged, and 57.36gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c. Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 400.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.Ogm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 44.0gm of brown -Meta hydroxy acetophenone with M.P.- 94°c. Mother liquor is stored for recycle after treatment.

Forty-fifth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 44th recycle batch was charged, and 44.40gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c. Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (lG,0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 400.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.0gm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 47.0gm of brown -meta hydroxy acefopftenone with M.P.-92°c. Mother liquor is stored for recycle after treatment.
Sixtieth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 59th recycle batch was charged, and 66.79gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c. Further tot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 400.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.Ogm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 5 l.Ogm of brown -Meta hydroxy acetophenone with M.P.- 90°c. Mother liquor is stored for recycle after treatment.

Seventy Fifth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 74th recycle batch was charged, and 62.23gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5°c- Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10,0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 400.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.0gm decolorizing agent & rise temperature up to 95°c & maintained for 60min. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 50.0gm of brown -Meta hydroxy acetophenone with M.P.- 91°c. Mother liquor is stored for recycle after treatment.
Seventy eighth cycle: In the same set up as described above, 256.0 ml, of reaction medium generated in 77th recycle batch was charged, and 52.74gm sulphuric acid at room temperature. Diluted sulphuric acid solution was chilled to 0°c with ice cooling & then charged first lot of lO.Ogm MAA (Meta amino aceto phenone) & 12.0ml sodium nitrite solution (NaNo2) below 5V Further lot of MAA (Meta amino aceto phenone) & sodium nitrite solution (10.0ml*4) charged in four equal lots in similar manner as followed for first lot. Then charged solution of 2.5gm Cupric sulphate in 50.0ml water & maintained the reaction mass for 3-hrs. Charged 400.0ml NPC treated reaction medium for dilution of reaction mass. Total reaction mass was heated to 70°c & charged l.Ogm decolorizing agent & rise temperature up to 95°c & maintained for 60mifl. Further it is cooled to room temperature & maintained 2-l/2hrs for crystallization. Total reaction mass was filtered & washing 50.0ml of purification mother liquor to get on drying 34.0gm

of brown -Meta hydroxy acetophenone with M.P.- 90°c. Mother liquor is stored for recycle after treatment.
The following examples illustrate the utility of the purification/isolation sequence of Meta Hydroxyacetophenone using the process described in the present invention.
First Cycle: In a 2 - liter -4 necks round bottom flask equipped with stirrer, condenser, thermometer, and addition port arranged in suitable heating/cooling system was charged 450.0ml purification reaction medium heated to 95°C & charged 25.0gm crude MHA with continuous stirring at 95°C. 0.7gm NPC (Newreka pH Catalyst) was charged during 5 min to adjust pH of the reaction mass to 7.0. 0.5 gm activated carbon was charged at 95°C & maintain for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 2.0 gm off white meta hydroxy acetophenone was charged as seeding and aqueous layer in the crystallizer was cooled to room temperature, maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying 8.0gm of pale yellow -meta hydroxy acetophenone with melting point -95°C. Reaction medium was stored for recycle.
Fifth Cycle: In the same set up as described above charged 270.0ml purification reaction medium generated in 4th cycle, heated to 95°C & charged 15.0 gm crude MHA with continuous stirring at 95°C. 0.4 gm NPC (Newreka pH Catalyst) was charged during 5 min to adjust pH of the reaction mass to 7.0. 0.3 gm activated carbon was charged at 95°C & maintain for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 1.2gm off white meta hydroxy acetophenone was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C, maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying 9.0gm of yellow-meta hydroxy acetophenone with melting point -95°C. Reaction medium was stored for recycle.

Twelfth Cycle: In the same set up as described above charged 450.0ml purification reaction medium generated in IIth cycle, heated to 95°C & charged 25.0gm crude MHA with continuous stirring at 95°C. 0.7gm NPC (Newreka pH Catalyst) was charged during 5 min to adjust pH of the reaction mass to 7.0. 1.0 gm activated carbon was charged at 95°C & maintain for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 2.0gm off white meta hydroxy acetophenone was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C, maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying l0.0gm of yellow-meta hydroxy acetophenone with melting point -96°c. Reaction medium was stored for recycle.
Twentieth Cycfe: fn the same set up as described above charged 450.0ml purification reaction medium generated in 19th cycle, heated to 95°C & charged 25.0gm crude MHA with continuous stirring at 95°C. 1.2 gm NPC (Newreka pH Catalyst) was charged during 5 min to adjust pH of the reaction mass to 7.0. 1.0 gm activated carbon was charged at 95°C & maintain for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 2.0gm off white meta hydroxy acetophenone was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C, maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying lO.Ogm of pale yellow-meta hydroxy acetophenone with melting point -96°c. Reaction medium was stored for recycle.
Thirty Sixth Cycle: In the same set up as described above charged 600.0 ml purification reaction medium generated in 35th cycle, heated to 95°C & charged I5.0gm crude MHA with continuous stirring at 95°C 0.15 gm decolorizing agent was charged during 5 min in the reaction mass &, maintain for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 1.2 gm off white

meta hydroxy acetophenonee was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C and maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying 10.0 gm of pale yellow-meta hydroxy acetophenonee with melting point -96°c. Reaction medium was stored for recycle.
Forty Fifth Cycle: In the same set up as described above charged 600.0ml purification reaction medium generated in 44th cycle, heated to 95°C & charged 15.0gm crude MHA with continuous stirring at 95°C and 0.15gm decolorizing agent was charged during 5 min in the reaction mass, maintained for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 1.2gm off white meta hydroxy acetophenonee was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C and maintained for two hour with continuous hydrose water solution.Crystalline material was filtered to get on drying 12.0gm of yellow-meta hydroxy acetophenonee with melting point -96°C. Reaction medium was stored for recycle.
Sixty Ninth Cycle: In the same set up as described above charged 600.0ml purification reaction medium generated in 68th cycle, heated to 95°C & charged 15.0gm crude MHA with continuous stirring at 95°C. 0.15gm decolorizing agent was charged during 5 min in the reaction mass & maintained for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 1.2gm off white meta hydroxy acetophenone was charged as seeding and aqueous layer in the crystallizer was cooled to 10°C and maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying 9.0gm of yellow -meta hydroxy acetophenone with melting point -96°C. Reaction medium was stored for recycle.
Seventy Eighth Cycle: In the same set up as described above, 600.0ml charged purification reaction medium generated in 77th cycle, heated to 95°C & charged

15.0gm crude MHA with continuous stirring at 95°C. 0.15gm decolorizing agent was charged during 5 min in the reaction mass & maintained for 30 min. Then aqueous layer was filtered to crystallizer and cooled to 60°C. 1.2gm off white meta hydroxy acetophenone was charged as seeding. Aqueous layer in the crystallizer was cooled to 10°C and maintained for two hour with continuous hydrose water solution. Crystalline material was filtered to get on drying ll.0gm of yellow -meta hydroxy acetophenone with melting point -96°C. Reaction medium was stored for recycle.
In view of the detailed foregoing description of the present invention, it will be apparent to a person skilled in the art that the present invention basically comprises the following items:
1. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, comprising a plurality of cycles, each of said cycles comprising a green reaction sequence and a green isolation sequence, wherein said green isolation sequence follows said green reaction sequence.
2. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as described in item 1, wherein the number of said plurality of cycles is preferably greater than 10, more preferably greater than 25, even more preferably greater than 100.
3. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds 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, denoted as start-up RM, to a jacketed 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 weight of the RM used being in the range of 1 to 25 times the dry weight of the Ar-NH2 used in the batch, more preferably in the range from 1 to 15 times, even more preferably in the range from 1 to 10 times;
stage 1.1b: optionally adding an acid or a salt in a suitable form and quantity, wherein said acid is preferably sulfuric acid, and wherein said salt is made from a metal with inorganic or organic acid, and wherein the temperature of the mixture in the reaction medium is maintained in the range from of 0°C to 35°C, preferable range being 0°C to 20°C; more preferable range being 0°C to 10°C;
wherein the mixture in the vessel is agitated for a duration in the range from 0 minutes to 5 hours, preferably in the range from 0.5 hours to 3 hours and more preferably from 0.5 hours to 2.5 hours, and
wherein the pH of the mixture in the vessel is maintained in the range from 1 to 9, preferably in the range from 2 to 7, more preferable in the range from 2 to 4;
Step 1.2:

Stage 1.2a: adding a suitable quantity, X, of Ar-NH2 compound to the reaction vessel;
Stage 1.2b: adding a quantity, Y, of solution of NaN02; wherein the quantity, Y, of NaN02 to be used to make a NaN02 solution is calculated in terms of the theoretical quantity, X', of the NaN02 required to complete the reaction, as per the following equation:
X' = (Total quantity of Ar-NH2) *Mc>l. Wt of NaN02(Theoretical)
(Mol. WtofAr-NH2)
and wherein Y is calculated as per the following equation:
Y = CX';
wherein C is in the range between 1.1 to 1.2;
and wherein the solution of NaN02 is made by dissolving said Y quantity of NaN02 in a quantity of FRM which is in the range from 0.5 to 2 times Y,
and wherein the NaN02 solution is charged to the reaction mass of Step 1.2 either in its full quantity or in any number of lots,
and wherein the Ar-NH2 compound and NaN02 solution are added to the reaction mixture over a period in the range from 0 to 25 hours, at a suitable interval of time depending on the molecule to be diazotized,

and wherein the temperature of the reaction mixture is maintained in the range from 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C,
and wherein the reaction mixture is agitated for a period in the range of 1 hours to 25 hours, preferable range being 1 hour to 20 hours; more preferable range being 1 hour to 12 hours; wherein the agitation is continued till all Ar-NH2 is depleted;
and wherein the pH of the reaction mixture is maintained in the range from 1 to 9, preferably in the range of 2 to 7, more preferable range being 2 to 4;
Step 1.3:
diluting the reaction mixture obtained at the end of Step 1.2 by adding to it a suitable dilution medium, the weight of said dilution medium being 0 to 30 times the dry weight of the Ar-NH2 used in the batch;
wherein the total mass in the reaction vessel is maintained at a dilution temperature in the range of 0°C to 35°C, preferably in the range from 0° to 20°C; more preferably in the range from 0°C to 10°C, wherein
the diluted reaction mixture is agitated for a duration in the range from 0 hours to 10 hours, preferably in the range from 30 minutes to 5 hours, more preferably in the range from 30 minutes to 2 hours;
whereafter the diluted reaction mixture is cooled using a predetermined cooling curve to post-dilution temperature in the range from 0°C to 35°C, and

such that the pH of the diluted reaction mixture is in the range from 1 to 9, preferably in the range of 2 to 7, more preferably in the range from 2 to 4,
and wherein the cooling period is in the range from for 0 hours to 8 hours, preferably in the range from 30 minutes to 4 hours;
Step 1.4:
Stage 1.4a - filtering the total mass from Step 1.3 using any method known to a person skilled in the art, wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, preferably in the range from 0°C to 35°C, more preferably in the range from 0° to 20°C; even more preferably in the range from 0°C to 10°C; storing the filtered liquid as Stream IE into a washings storage tank)
Stage 1.4b - washing the filtered mass, with a quantity of first washing medium, the weight whereof is in the range from 0 to 5 times the dry weight of the Ar-NH2 being used in the batch, preferably in the range from 0.1 to 2.0 times, at a first washing temperature that is in the range from 0°C to 100°C, preferably in the range from 0°C to 35°C, more preferably in the range from 0° to 20°C; even more preferably in the range from 0°C to 10°C, the washing being carried out till the washings (referred to as Stream 1 A) show a pH in the range from 1 to 9, preferably in the range from 2 to 7, more preferably in the range from 2 to 4;
storing a part of Stream 1A as start-up mother liquor (referred to as Stream IB) into a start-up mother liquor storage tank; sending the remaining part of Stream A as Stream 1C to Step 1.5;

Step 1.5:
charging to Stream 1C a first neutralising agent, NDHF, that is a proprietary diazotization-hydrolysis agent, the weight of said NDHF agent being 0 to 0.01 times the dry weight of the Ar-NH2, preferably in the range from 0.0005 to 0.005 times;
wherein the temperature of the treated mixture charged with said NDHF agent is maintained in the range from 0°C to 100°C, preferably 40°C to 80°C, more preferably 60°C to 70°C,
further wherein the duration of charging said NDHF-agent the treatment agent is in the range from 0 hours to 5 hours, preferably in the range from 30 minutes to 2 rrotrrs, by mafrrtafnrng the pH of tfie treated fiftrate in trie range from 1 to 9, preferable range being 2 to 7 and more preferable range being 4 to 6;
whereafter the total treated filtrate is maintained at a temperature in the range from 0°C to 100oC, preferably 40°C to 80°C, more preferably 60°C to 70°C for a duration in the range from 0 hours to 5 hours, preferable range being 30 minutes to 2 hours;
Step 1.6:
Stage 1.6a - filtering the total mass obtained a.t the end of Step 1.5 by any methods known to a person skilled in the art; wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, preferably in the range from 40°C to 80°C, more preferably in the range from 60° to 70°C;

Stage 1.6b - washing the filtered mass of stage 1.6b with a second washing medium, taken as stream ID from the start-up mother liquor storage tank, the weight of said second washing medium being in the range from 0.5 to 2 times the dry weight of Ar-NH2 used in the batch, and the temperature of said second washing medium being maintained within a temperature range from 0°C to 100°C, preferably in the range from 40°C to 80°C, more preferably in the range from 60° to 70°C;
wherein washing is carried out at a washing temperature that is in the range of 0°C to. 100°C, preferable range being 40°C to 80°C, more preferable range being 60°C to 70°C and at a pH in the range from 1 to 9, preferable range being 2 to 7 and more preferable range being 4 to 6.
Stage 1 .6c - storing the filtrate (stream IF) obtained from stage 1.6a into a hot mother liquor storage tank;
Step 1.7:
Stage 1.7a - charging the washings obtained from stage 1.6c and the washings
storage tank 1.4b together or separately taken in suitable quantities
Stage 1.7b- adding a second neutralising agent, that is NDFH, the quantity of
which is in the range of 0 to 0.02 times the dry weight of Ar-NH2 used in the
batch,
wherein in the temperature of the neutralisation mixture obtained at the end of stage 1.7b is maintained in the range of 0°C to 100°C, preferable range being 40° to 70°C,
and wherein the pH of the neutralisation mixture is in the range of 1 to 9 , preferable range being 5 to 8, more preferable range being 5.5 to 7.5;

and wherein the total mass obtained at the end of stage 1.7b is maintained at a temperature in the range of 0°C to 100°C, preferable range being 40° to 70°C for 0 hours to 2 hours; preferable range being 30 minutes to 1 hour;
Step 1.8:
Stage 1.8 a - filtering the total mass obtained at the end of Step 1.7 by known methods wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C preferable range being 40°C to 70°C.
Stage 1.8b - washing the filtrate obtained at the end of stage 1.8a with a washing medium, the quantity of which is in the range of 0 to 5 times the dry weight of Ar-NH2 used in the batch, preferable range being in the range of 0.5 to 2 times,
wherein the washing is carried out till the pH of the washings obtained is in the range of 1 to 9, preferable range being 5 to 8S more preferable range being 5.5 to 7.5;
Step 1.9:
evaporating the filtrate generated at the end of step 1.8 by natural means or by any method known to a person skilled in the art;
whereby a single cycle of said green reaction sequence is completed, and whereafter a cycle of green isolation sequence is carried out, said green isolation sequence comprising the following steps:
Step 2.1:
Stage 2.1a-

charging into a second jacketed reactor with agitator and other known attachments a dissolution reaction medium comprising fresh reaction medium and a solvent in the weight ratio of 75:25 respectively, wherein the.weight of said dissolution reaction medium is in the range from 0 to 100 times the weight of crude Ar-OH that is to be processed in the batch, preferably in the range from 10 to 75 times, more preferably in the range from 10 to 50 times,
Stage 2.1b - dispersing a quantity of crude Ar-OH crystals obtained using a dispersion medium, the weight of said dispersion medium being in the range from approximately twice the dry weight of crude Ar-NH2 to be dispersed, wherein the dispersion is carried out at a temperature in the range of 0°C to 100°C, preferable range being 25°C to 75°C, with the mixture being agitated throughout the dispersion stage,
wherein the time of agitation being in the range from 0 hours to 10 hours, preferable range being 30 minutes to 2 hours so that the Ar-OH crystals are broken down to a size that can dissolve in the dissolution reaction medium;
Stage 2.1c-
charging said second jacketed reactor with the dispersed Ar-OH obtained at the end of stage 2.1b, by maintaining the dissolution temperature in the range of 0°C to 75°C, preferable range being 25°C to 75°C, and wherein the dissolution time is in the range of 0 hours to 5 hours, preferable range being 30 minutes to 2 hours; and wherein the mixture is agitated throughout the dissolution stage 2.1c,
Stage 2.ld-
adding a third neutralizing agent, NDHF, wherein the weight of said third neutralizing agent is in the range from 0 to 0.25 times the dry weight of crude Ar-NH2 to be processed in the batch, preferably in the range from 0.005 to

0.05 times, so that the pH of the mixture is adjusted to bring it in the range from 1 to 9, preferably in the range 5.5 to 7.5,
wherein the temperature in the neutralization stage is maintained in the range of 0°C to 100°C, more preferable range being 25°C to 75°C, and wherein the mixture is agitated throughout the neutralization stage 2. Id;
Stage 2.le-
charging activated carbon, weight of said activated carbon being in the range from 0 to 0.08 times the dry weight of the crude Ar-OH being processed in the batch, preferably in the range from 0.005 to 0.05% (w/w), and wherein the mixture is agitated throughout the purification stage 2.1e;
Step 2.2:
filtering the total mass obtained at the end of Step 2.1 by methods known to a person skilled in the art, wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, more preferable range being 25°C to 75°C,
and wherein the Alteration is carried out without agitation, in the range of time from 0 hours to 10 hours, preferable range being 30 minutes to 5 hours maintaining the PH in the range of Ito 9, preferably in the range 5.5 to 7.5j
Step 2.3:
Stage 2.3a-
charging into a third jacketed reactor equipped with an agitator the total
filtrate obtained in Step 2.2;

Stage 2.3b-
adding to said third jacketed reactor seed crystals of pure Ar-OH, white
maintaining the temperature of the filtrate in the range of 0°C to 100°C,
preferable range being 60°C to 80°C, more preferable range being 55°C to
65°C;
wherein the weight of said seed crystals added is in the range from 0 to 0.1 times the weight of the crude Ar-OH to be processed in the batch, preferably in the range from 0.005 to 0.08 times, more preferably in the range from 0.01 to 0.05 times;
Step 2.4:
Stage 2 Aa -
filtering by methods known to person skilled in the art, the total mass
obtained at the end of Step 2.3,
wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 50°C, preferably 5°C to 25°C;
Stage 2.4b -
washing the filtered mass obtained at the end of stage 2.4a with a third washing medium, said third washing medium preferably being fresh reaction medium, more preferably fresh water, wherein the weight of said third washing medium is in the range from 0 to 1 times the dry weight crude Ar-OH, preferably in the range from 0.1 to 0.6 times;
wherein the pH of the washings obtained at the end of stage 2.4b is maintained in the range from 5 to 8, preferably in the range 5-5 to 7.5;

Stage 2.4c -
storing together the washings from stage 2.4b into a mother liquor storage
tank;
Step 2.5: drying the pure Ar-OH obtained at the end of Step 2.4 by methods known to a person skilled in the art; wherein the temperature used for the drying purpose is in the range of 0°C to 100°C, preferable range being 50°C to 70°C, and wherein the drying process is carried out over a period in the range from 0 hour to 24 hours, preferable range being 1 hour to 10 hours;
Step 2.6:
pulverising the pure dry Ar-OH obtained at the end of Step 2.5 is pulverised by known method;
Step 2.7: packaging the Ar-OH obtained at the end of Step 2.6.
4. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 3, wherein said chemical process is carried out in a match mode or in a continuous or semicontinuous form, or any combination thereof.
5. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in any of the claims 1 to 4 wherein any methods known to a person skilled in the art is used to separate the crude Ar-OH in place of said steps 1.3 and 1.4.
6. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed

in any of the claims 1 to 5, wherein any methods known to a person skilled in the art is used to separate pure Ar-OH in place of steps said 2.3 and 2.4.
7. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 6, wherein any weak alkali is used in place of NDHF in said steps 1.5, 1.7, and 2.1.
8. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 7, wherein nitrites of any of the group comprising calcium, sodium, potassium, and ammonia, or any combination thereof, or the nitrous acid is used, in place of sodium nitrite.
9. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims i to 8, wherein the reaction vessels may be of any type suitable for the green conversion chemical processes, and wherein the agitators are of any suitable type, and wherein filters are of any suitable type known to a person skilled in the art.
While the above description contains many specificities, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. Many other variations are possible. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

We claim:
1. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, comprising a plurality of cycles, each of said cycles comprising a green reaction sequence and a green isolation sequence, wherein said green isolation sequence follows said green reaction sequence.
2. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claim 1, wherein the number of said plurality of cycles is preferably greater than 10, more preferably greater than 25, even more preferably greater than 100.
3. A process as claimed in any of claims 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. la-charging a suitable reaction medium, denoted as start-up RM, to a jacketed 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 weight of the RM used being in the range of 1 to 25 times the dry weight of the Ar-NH2 used in the batch, more preferably in the range from 1 to 15 times, even more preferably in the range from 1 to 10 times;

stage 1.1b-
optionally adding an acid or a salt in a suitable form and quantity, wherein
said acid is preferably sulfuric acid, and wherein said salt is made from a
metal with inorganic or organic acid, and wherein the temperature of the
mixture in the reaction medium is maintained in the range from of 0°C to
35°C, preferable range being 0°C to 20°C; more preferable range being 0°C to
10°C;
wherein the mixture in the vessel is agitated for a duration in the range from 0 minutes to 5 hours, preferably in the range from 0.5 hours to 3 hours and more preferably from 0.5 hours to 2.5 hours, and
wherein the pH of the mixture in the vessel is maintained in the range from 1 to 9, preferably in the range from 2 to 7, more preferable in the range from 2 to 4;
Step 1.2:
Stage 1 Padding a suitable quantity, X, of Ar-NH2 compound to the reaction vessel;
Stage 1.2b-
adding a quantity, Y, of solution of NaN02;
wherein the quantity, Y, of NaN02 to be used to make a NaN02 solution is
calculated in terms of the theoretical quantity, X', of the NaN02 required to
complete the reaction, as per the following equation:


and wherein Y is calculated as per the following equation:
Y = CX';
wherein C is in the range between 1.1 to 1.2;
and wherein the solution of NaN02 is made by dissolving said Y quantity of NaN02 in a quantity of FRM which is in the range from 0.5 to 2 times Y,
and wherein the NaN02 solution is charged to the reaction mass of Step 1.2 either in its full quantity or in any number of lots,
and wherein the Ar-NH2 compound and NaN02 solution are added to the reaction mixture over a period in the range from 0 to 25 hours, at a suitable interval of time depending on the molecule to be diazotized,
and wherein the temperature of the reaction mixture is maintained in the range from 0°C to 35°C, preferable range being 0° to 20°C; more preferable range being 0°C to 10°C,
and wherein the reaction mixture is agitated for a period in the range of 1 hours to 25 hours, preferable range being 1 hour to 20 hours; more preferable range being 1 hour to 12 hours; wherein the agitation is continued till all Ar-NH2 is depleted;
and wherein the pH of the reaction mixture is maintained in the range from 1 to 9, preferably in the range of 2 to 7, more preferable range being 2 to 4;

Step 1.3: diluting the reaction mixture obtained at the end of Step 1.2 by adding to it a suitable dilution medium, the weight of said dilution medium being 0 to 30 times the dry weight of the Ar-NH2 used in the batch;
wherein the total mass in the reaction vessel is maintained at a dilution temperature in the range of 0°C to 35°C, preferably in the range from 0° to 20°C; more preferably in the range from 0°C to 10°C, wherein
the diluted reaction mixture is agitated for a duration in the range from 0 hours to 10 hours, preferably in the range from 30 minutes to 5 hours, more preferably in the range from 30 minutes to 2 hours;
whereafter the diluted reaction mixture is cooled using a predetermined cooling curve to post-dilution temperature in the range from 0°C to 35°C, and such that the pH of the diluted reaction mixture is in the range from 1 to 9, preferably in the range of 2 to 7, more preferably in the range from 2 to 4,
and wherein the cooling period is in the range from for 0 hours to 8 hours, preferably in the range from 30 minutes to 4 hours;
Step 1.4:
Stage 1.4a -
filtering the total mass from Step 1.3 using any method known to a person skilled in the art, wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, preferably in the range from 0°C to 35°C, more preferably in the range from 0° to 20°C; even more preferably in the range from 0°C to 10°C; storing the filtered liquid as Stream IE into a washings storage tank;

Stage 1.4b -
washing the filtered mass, with a quantity of first washing medium, the weight whereof is in the range from 0 to 5 times the dry weight of the Ar-NH2 being used in the batch, preferably in the range from 0.1 to 2.0 times, at a first washing temperature that is in the range from 0°C to 100°C, preferably in the range from 0°C to 35°C, more preferably in the range from 0° to 20°C; even more preferably in the range from 0°C to 10°C, the washing being carried out till the washings (referred to as Stream 1A) show a pH in the range from 1 to 9, preferably in the range from 2 to 7, more preferably in the range from 2 to 4;
storing a part of Stream 1C as start-up mother liquor (referred to as Stream IB) into a start-up mother liquor storage tank; sending the remaining part of Stream A as Stream 1C to Step 1.5;
Step 1.5:
charging to Stream 1C a first neutralising agent, NDHF, that is a proprietary diazotizati on-hydro lysis agent, the weight of said NDHF agent being 0 to 0.01 times the dry weight of the Ar-NH2, preferably in the range from 0.0005 to 0.005 times;
wherein the temperature of the treated mixture charged with said NDHF agent is maintained in the range from 0°C to 100°C, preferably 40°C to 80°C, more preferably 60°C to 70°C,
further wherein the duration of charging said NDHF-agent the treatment agent is in the range from 0 hours to 5 hours, preferably in the range from 30 minutes to 2 hours, by maintaining the pH of the treated filtrate in the range

from I to 9, preferable range being 2 to 7 and more preferable range being 4 to 6;
whereafter the total treated filtrate is maintained at a temperature in the range from 0°C to 100°C, preferably 40°C to 80°C, more preferably 60°C to 70°C for a duration in the range from 0 hours to 5 hours, preferable range being 30 . minutes to 2 hours;
Step 1.6:
Stage 1.6a-
filtering the total mass obtained at the end of Step 1.5 by any methods known to a person skilled in the art; wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, preferably in the range ftom 40°C to 80°C, moTe preferably in the Tange from 60° to 70°C;
Stage 1.6b -
washing the filtered mass of stage 1.6b with a second washing medium, taken as stream ID from the start-up mother liquor storage tank, the weight of said second washing medium being in the range from 0.5 to 2 times the dry weight of Ar-NH2 used in the batch, and the temperature of said second washing medium being maintained within a temperature range from 0°C to 100°C, preferably in the range from 40°C to 80°C, more preferably in the range from 60° to 70°C;
wherein washing is carried out at a washing temperature that is in the range of 0°C to 100°C, preferable range being 40°C to 80°C, more preferable range being 60°C to 70°C and at a pH in the range from 1 to 9, preferable range being 2 to 7 and more preferable range being 4 to 6;
Stage 1.6c -

storing the filtrate (stream IF) obtained from stage 1.6a into a hot mother liquor storage tank;
Step 1.7:
Stage 1.7a-
charging the washings obtained from stage 1.6c and the washings storage tank
1.4b together or separately taken in suitable quantities}
Stage 1.7b-
adding a second neutralising agent, that is NDFH, the quantity of which is in
the range of 0 to 0.02 times the dry weight of Ar-NH2 used in the batch,
wherein in the temperature of the neutralisation mixture obtained at the end of stage 1.7b is maintained in the range of 0°C to 100°C, preferable range being 40° to 70°C,
and wherein the pH of the neutralisation mixture is in the range of 1 to 9 , preferable range being 5 to 8, more preferable range being 5.5 to 7.5;
and wherein the total mass obtained at the end of stage 1.7b is maintained at a temperature in the range of 0°C to 100°C, preferable range being 40° to 70°C for 0 hours to 2 hours; preferable range being 30 minutes to 1 hour;
Step 1.8:
Stage 1.8a-
filtering the total mass obtained at the end of Step \ .7 by known methods wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, preferable range being 40°C to 70°C;
Stage 1.8b-

washing the filtrate obtained at the end of stage 1.8a with a washing medium, the quantity of which is in the range of 0 to 5 times the dry weight of Ar-NH2 used in the batch, preferable range being in the range of 0.5 to 2 times,
wherein the washing is carried out till the pH of the washings obtained is in the range of 1 to 9, preferable range being 5 to 8, more preferable range being 5.5 to 7.5;
Step 1.9:
evaporating the filtrate generated at the end of step 1.8 by natural means or by any method known to a person skilled in the art;
whereby a single cycle of said green reaction sequence is completed, and whereafter a cycle of green isolation sequence is carried out, said green isolation sequence comprising the following steps:
Step 2.1:
Stage 2.1a-
charging into a second jacketed reactor with agitator and other known attachments a dissolution reaction medium comprising fresh reaction medium and a solvent in the weight ratio of 75:25 respectively, wherein the weight of said dissolution reaction medium is in the range from 0 to 100 times the weight of crude Ar-OH that is to be processed in the batch, preferably in the range from 10 to 75 times, more preferably in the range from 10 to 50 times;
Stage 2.1b-
dispersing a quantity of crude Ar-OH crystals obtained using a dispersion medium, the weight of said dispersion medium being in the range from approximately twice the dry weight of crude Ar-NH2 to be dispersed, wherein the dispersion is carried out at a temperature in the range of 0°C to 100°C,

preferable range being 25°C to 75°C, with the mixture being agitated throughout the dispersion stage,
wherein the time of agitation being in the range from 0 hours to 10 hours, preferable range being 30 minutes to 2 hours so that the Ar-OH crystals are broken down to a size that can dissolve in the dissolution reaction medium;
Stage 2.1c-
charging said second jacketed reactor with the dispersed Ar-OH obtained at the end of stage 2.1b, by maintaining the dissolution temperature in the range of 0°C to 75°C, preferable range being 25°C to 75°C, and wherein the dissolution time is in the range of 0 hours to 5 hours, preferable range being 30 minutes to 2 hours; and wherein the mixture is agitated throughout the dissolution stage 2.1c;
Stage 2.1d-
adding a third neutralizing agent, NDHF, wherein the weight of said third neutralizing agent is in the range from 0 to 0.25 times the dry weight of crude Ar-NH2 to be processed in the batch, preferably in the range from 0.005 to 0.05 times, so that the pH of the mixture is adjusted to bring it in the range from 1 to 9, preferably in the range 5.5 to 7.5;
wherein the temperature in the neutralization stage is maintained in the range of 0°C to 100°C, more preferable range being 25°C to 75°C, and wherein the mixture is agitated throughout the neutralization stage 2.1d,-
Stage 2.le-
charging activated carbon, weight of said activated carbon being in the range
from 0 to 0.08 times the dry weight of the crude Ar-OH being processed in the

batch, preferably in the range from 0.005 to 0.05% (w/w), and wherein the mixture is agitated throughout the purification stage 2.1e;
Step 2.2: filtering the total mass obtained at the end of Step 2.1 by methods known to a person skilled in the art, wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 100°C, more preferable range being 25°C to 75°C,
and wherein the Alteration is carried out without agitation, in the range of time from 0 hours to 10 hours, preferable range being 30 minutes to 5 hours maintaining the PH in the range of lto 9, preferably in the range 5.5 to 7.5j
Step 2.3:
Stage 2.3a-
charging into a third jacketed reactor equipped with an agitator the total
filtrate obtained in Step 2.2;
Stage 2.3b -
adding to said third jacketed reactor seed crystals of pure Ar-OH, while
maintaining the temperature of the filtrate in the range of 0°C to 100°C,
preferable range being 60°C to 80°C, more preferable range being 55°C to
65°C;
wherein the weight of said seed crystals added is in the range from 0 to 0.1 times the weight of the crude Ar-OH to be processed in the batch, preferably in the range from 0.005 to 0.08 times, more preferably in the range from 0.01 to 0.05 times;

Step 2.4:
Stage 2.4a -
filtering by methods known to person skilled in the art, the total mass
obtained at the end of Step 2.3,
wherein the temperature of the slurry being filtered is maintained in the range from 0°C to 50°C, preferably 5°C to 25°C;
Stage 2.4b -
washing the filtered mass obtained at the end of stage 2.4a with a third washing medium, said third washing medium preferably being fresh reaction medium, more preferably fresh water, wherein the weight of said third washing medium is in the range from 0 to 1 times the dry weight crude Ar-OH, preferably in the range from 0.1 to 0.6 times;
wherein the pH of the washings obtained at the end of stage 2.4b is maintained in the range from 5 to 8, preferably in the range 5.5 to 7.5:
Stage 2.4c -
storing together the washings from stage 2.4b into a mother liquor storage
tank;
Step 2.5: drying the pure Ar-OH obtained at the end of Step 2.4 by methods known to a person skilled in the art; wherein the temperature used for the drying purpose is in the range of 0°C to 100°C, preferable range being 50°C to 70°C, and wherein the drying process is carried out over a period in the range from 0 hour to 24 hours, preferable range being 1 hour to 10 hours;

Step 2.6:
pulverising the pure dry Ar-OH obtained at the end of Step 2.5 is pulverised by known method;
Step 2.7: packaging the Ar-OH obtained at the end of Step 2.6.
4. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 3, wherein said chemical process is carried out in a match mode or in a continuous or semicontinuous form, or any combination thereof.
5. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in any of the claims 1 to 4 wherein any methods known to a person skilled in the art is used to separate the crude Ar-OH in place of said steps 1.3 and 1.4.
6. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in any of the claims 1 to 5, wherein any methods known to a person skilled in the art is used to separate pure Ar-OH in place of steps said 2.3 and 2.4.
7. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 6, wherein any weak alkali is used in place of NDHF in said steps 1.5, 1.7, and 2.1,
8. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 7, wherein nitrites of any of the group comprising calcium, sodium, potassium, and ammonia, or any combination thereof, or the nitrous acid is used, in place of sodium nitrite.

9. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 8, wherein the reaction vessels may be of any type suitable for the green conversion chemical processes, and wherein the agitators are of any suitable type, and wherein filters are of any suitable type known to a person skilled in the art.
9. A sustainable chemical process of green conversion of aromatic amino compounds into corresponding aromatic hydroxy compounds, as claimed in claims 1 to 8, wherein the reaction vessels may be of any type suitable for the green conversion chemical processes, and wherein the agitators are of any suitable type, and wherein filters are of any suitable type known to a person skilled in the art.
Dated this 6th Day of July, 2007

To,
The Controller of Patents
The Patent Office, Mumbai Branch
Baudhik Sarnpada Bhavan,
Antop Hill, Mumbai 400 037