DESC:FIELD
The present disclosure relates to a process for the preparation of Oxyfluorfen.
DEFINITION
As used in the present disclosure, the following term is generally intended to have the meaning as set forth below, except to the extent that the context in which it is used indicates otherwise.
Oxyfluorfen – refers to a chemical compound which is a derivative of diphenyl ether and is used as an herbicide.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Oxyfluorfen acts as an herbicide that is used against a wide range of weeds. The herbicide is used against both pre-emergence and post-emergence treatment of weeds and controls a wide variety of seasonal/annual broadleaf weeds and weed grasses in soybeans, corn, cotton, grapes, nuts, spearmint, and many other tropical plantations and ornamental crops.
Conventionally the processes for the preparation of Oxyfluorfen suffer from the shortcoming of low yields, time consuming, and therefore, energy intensive. Further, the purity of the Oxyfluorfen obtained is poor.
Therefore, there is felt a need to provide a process for the preparation of Oxyfluorfen that mitigates the drawbacks mentioned hereinabove.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide an economical process for the preparation of Oxyfluorfen.
Still another object of the present disclosure is to provide a process that gives a high yield of Oxyfluorfen
Yet another object of the present disclosure is to provide a process that provides a high purity Oxyfluorfen.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a process for the preparation of Oxyfluorfen. The process comprises dissolving at least one weak base in at least one first fluid medium to obtain a solution. A first portion of 2-Chloro-4-trifluoromethyl phenol is added to the solution under stirring at a temperature in the range of 25 °C to 35 °C to obtain a mixture. To the mixture 2-ethoxy-4-fluoro nitrobenzene is added and reacted at a first predetermined temperature for a first predetermined time period to obtain a reaction mass. At least two portions of 2-chloro-4-trifluoromethyl phenol are added to the reaction mass at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising Oxyfluorfen and Oxyfluorfen analogue. The so obtained product mixture is purified by using at least one second fluid medium to obtain pure Oxyfluorfen.

DETAILED DESCRIPTION
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
Oxyfluorfen acts as an herbicide which is used against a wide range of weeds. The herbicide is used against both pre-emergence and post-emergence treatment of weeds and controls a wide variety of seasonal/annual broadleaf weeds and weed grasses in soybeans, corn, cotton, grapes, nuts, spearmint, and many other tropical plantations and ornamental crops.
Conventionally, the processes for the preparation of Oxyfluorfen suffer from the shortcoming of low yields, time consuming, and therefore, energy intensive. Further, the purity of the Oxyfluorfen obtained is poor.
The present disclosure solves the problem by providing an economical, an energy saving, and rapid process which provides a comparatively high yield and high purity of Oxyfluorfen.
The present disclosure provides a process for preparing Oxyfluorfen. The process comprises reacting 2-Ethoxy-4-fluoro nitrobenzene and 2-Chloro-4-trifluoromethyl phenol at a predetermined molar ratio to obtain Oxyfluorfen.
Particularly, the present disclosure relates to a process for the preparation of Oxyfluorfen represented by formula (I):

(I)
The process for the preparation of Oxyfluorfen is described in detail as:
In a first step, at least one weak base is dissolved in at least one first fluid medium to obtain a solution.
In accordance with the present disclosure, the weak base is selected from the group consisting of potassium carbonate, sodium carbonate, and calcium carbonate. In an exemplary embodiment, the weak base is potassium carbonate.
In accordance with the present disclosure, the first fluid medium is selected from the group consisting of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and N-Methyl pyrrolidone (NMP). In an exemplary embodiment, the fluid medium is DMSO.
A first portion of 2-Chloro-4-trifluoromethyl phenol is added to the solution under stirring at a temperature in the range of 25 °C to 35 °C to obtain a mixture.
2-chloro-4-trifluoromethyl phenol contains 2-Chloro-5-trifluoromethyl phenol as an impurity. 2-Chloro-5-trifluoro methyl phenol is a contaminant which is co-produced during the process of preparation of 2-Chloro-4-trifluoromethyl phenol. The contaminant co-produced is not removed during the process of preparation of Oxyfluorfen and produces a low percentage of Oxyfluorfen analogue impurity which is removed during purification.
In accordance with the present disclosure, a weight ratio of the 2-chloro-4-trifluoromethyl phenol to the 2-chloro-5-trifluoromethyl phenol is in the range of 80:20 to 85:15.
In accordance with an embodiment of the present disclosure, the first portion of 2-chloro-4-trifluoromethyl phenol is in an amount in the range of 70 wt% to 85 wt% with respect to the total weight of 2-chloro-4-trifluoromethyl phenol. In an exemplary embodiment of the present disclosure, the first portion of 2-chloro-4-trifluoromethyl phenol is 83.3% with respect to the total weight of 2-chloro-4-trifluoromethyl phenol.
A schematic representation of the process of preparation of Oxyfluorfen is disclosed as given:

A predetermined amount of 2-ethoxy-4-fluoro nitrobenzene is added to the mixture followed by reacting 2-ethoxy-4-fluoro nitrobenzene with the mixture at a first predetermined temperature for a first predetermined time period to obtain a reaction mass.
In accordance with the present disclosure, the first predetermined temperature is in the range of 90 °C to 120 °C. In an exemplary embodiment, the first predetermined temperature is 100°C.
In accordance with the present disclosure, the first predetermined time period is in the range of 3 hours to 9 hours. In an exemplary embodiment, the first predetermined time period is 9 hours.
In accordance with an embodiment of the present disclosure, a molar ratio of 2-ethoxy 4-fluoro nitrobenzene to 2-chloro-4-trifluoromethyl phenol is in the range of 1:1.1 to 1:1.5. In an exemplary embodiment, the molar ratio is 1:1.2.
At least two portions of 2-chloro-4-trifluoromethyl phenol are added to the reaction mass at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising Oxyfluorfen and Oxyfluorfen analogue.
In accordance with the present disclosure, the second predetermined temperature is in the range of 90°C to 120°C. In an exemplary embodiment, the second predetermined temperature is 100°C.
In accordance with the present disclosure, the second predetermined time period is in the range of 3 hours to 15 hours. In an exemplary embodiment, the second predetermined time period is 8 hours.
In accordance with an embodiment of the present disclosure, at least two portions of 2-chloro-4-trifluoromethyl phenol are further added in an amount in the range of 5 wt% to 30 wt% independently for each portion with respect to the total weight of 2-chloro-4-trifluoromethyl phenol.
In one embodiment, 2-chloro-4-trifluoromethyl phenol is added portion-wise in a pre-determined manner. The addition of 2-chloro-4-trifluoromethyl phenol in portions helps to get the complete conversion. More amount of 2-chloro-4-trifluoromethyl is required if added in a single lot, because of degradation of 2-chloro-4-trifluoromethyl.
The so obtained product mixture comprising Oxyfluorfen and Oxyfluorfen analogue is purified using a second fluid medium to obtain pure Oxyfluorfen.
In accordance with the present disclosure, the second fluid medium is selected from hexane and toluene.
In accordance with the embodiment of the present disclosure, the second fluid medium is a mixture of hexane and toluene in the range of 70:30 to 80:20.
In the exemplary embodiment, the yield and the purity of so obtained Oxyfluorfen is 76% and 97.5% respectively.
In accordance with the present disclosure, 2-ethoxy-4-fluoro nitrobenzene and 2-chloro 4-trifluoro methyl phenol are prepared separately.
Process of preparation of 2-ethoxy-4-fluoro nitrobenzene
A process for the preparation of 2-ethoxy- 4-fluoro nitrobenzene comprises the following steps:
i) fluorination of 2,4 dichloro nitrobenzene to obtain a fluorinated product such as 2,4 difluoro nitrobenzene,2-fluoro-4-chloro nitrobenzene, and 2-chloro-4-fluoro nitrobenzene;
ii) hydrolysis of fluorinated products obtained in i) to obtain 4-fluoro-2-hydroxy nitrobenzene and 2-fluoro-4-hydroxy nitrobenzene (as impurity); and
iii) alkylating 4-fluoro-2-hydroxy nitrobenzene to obtain 2-ethoxy-4-fluoro nitrobenzene

A schematic disclosure of the process of preparation of 2-ethoxy-4-fluoronitrobenzene is disclosed as given:
Step i)

Step ii)

Step iii)

In accordance with the present disclosure, in step i) 2, 4 dichloro nitrobenzene is fluorinated with a fluorinating agent in a fluid medium in the presence of a catalyst to obtain 2, 4 difluoro nitrobenzene.
The fluorinating agent is KF.
2, 4 dichloro nitrobenzene and fluorinating agent are mixed in a pre-determined ratio. The process of fluorination is carried out in the presence of a catalyst which is selected from PEG-400, PEG-200, and PEG-600.
The fluid medium is selected from sulfolane and toluene. In an embodiment, a combination of sulfolane and toluene is used as a fluid medium.
In an exemplary embodiment, sulfolane, toluene, KF, and PEG-400 are mixed and 2,4 dichloro nitrobenzene is added in a molar ratio of 2,4 DCNB to KF 1:2.5 to obtain 2,4 difluoro nitrobenzene. In the exemplary embodiment, the yield and the purity of 2,4 difluoro nitrobenzene is 90% and 99.8% respectively.
In accordance with step ii) of the present disclosure, the so obtained 2,4 difluoro nitrobenzene is hydrolyzed by using a hydrolyzing agent in a pre-determined ratio at a predetermined temperature for a predetermined time period to obtain 4-fluoro-2-hydroxy nitrobenzene. The hydrolyzing agent is KOH.
In an exemplary embodiment, 2,4 difluoro nitrobenzene is mixed with water followed by adding KOH in a molar ratio of 1:2.2 to obtain 4-fluoro-2-hydroxy nitrobenzene. In the exemplary embodiment, the yield and the purity of 4-fluoro-2-hydroxy nitrobenzene is 90% and 99.6% respectively.
In accordance with step iii) of the present disclosure, the so obtained 4-fluoro-2-hydroxy nitrobenzene is mixed with an alkyl halide in a predetermined ratio to obtain 2-ethoxy-4-fluoro nitrobenzene. The alkyl halide is ethyl chloride.
In an exemplary embodiment, 4-fluoro-2-hydroxy nitrobenzene and ethyl chloride are mixed in a molar ratio of 1:1.2 to obtain 2-ethoxy-4-fluoro nitrobenzene. In the exemplary embodiment, the yield and the purity of 2 ethoxy-4-fluoronitrobenzene is 90% and 98.4% respectively.
Preparation of 2-chloro-4-trifluoro methyl phenol:
A schematic representation of the process of preparation of 2-chloro-4-trifluoro methyl phenol is illustrated as:

In accordance with the present disclosure, 3,4 dichloro benzotrifluoride is hydrolyzed by using a hydrolyzing agent to obtain 2-chloro-4-trifluoro methyl phenol. 2-chloro 5-trifluomethyl phenol is also obtained as a contaminant/impurity. The hydrolyzing agent is KOH. 3,4 dichloro benzotrifluoride and the hydrolyzing agent are mixed in a pre-determined ratio.
In an exemplary embodiment, 3,4 dichloro benzotrifluoride and KOH are mixed in a molar ratio of 1:3 to obtain 2-chloro-4- trifluoromethyl phenol and 2-chloro-5-trifluoromethyl phenol as an impurity. The yield of 2-chloro-4-trifluoromethyl phenol and 2-chloro-5-trifluoromethyl phenol is 66% and 8% respectively. The unreacted 3,4 dichloro benzotrifluoride is recovered.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Experiment 1: Preparation of 2,4 difluoro nitrobenzene (DFNB)
1250 ml of sulfolane, 625 ml toluene, 360 gm of KF, and 10 gm of PEG-400 were charged in a reactor to obtain a mixture and the mixture was heated to 130°C. Water and toluene were removed during the heating. 480 gm of 2,4-Dichloro nitrobenzene (2,4 DCNB) was added into the reactor and the reactor was further heated to 200°C for 18 hrs to obtain a reaction mass. The reaction was monitored by GLC and worked up to obtain 2,4-Difluoro nitrobenzene (358 gm; GLC purity = 99.8% Total Yield = 95%)

Recovery of KCl and KF from Inorganic material obtained from the conversion of 2,4-Difluoro nitrobenzene from 2,4-Dichloro nitrobenzene using KF.
Initial analysis of solids showed that KCl was 75% and KF was 25% of the total amount of the inorganic material.
100 ml of water was taken in a reactor and heated to 75°C. Added 100 gm of the inorganic material obtained from the conversion of 2,4, difluoro nitrobenzene from 2,4 dichloronitrobenzene, into it and the reactor temperature was further raised to 100°C to obtain a mass. The mass was stirred for one hour. 10 ml water was distilled out from the mass to remove any organic from the solids. The mass was subsequently cooled to 20°C, stirred, filtered, and vacuum dried. The weight of the residue was found to be 54 gms. The filtrate was concentrated.
Total KF recovered = 91%
Total KCl recovered = 98%

Experiment 2: Preparation of 4-fluoro-2-hydroxy nitrobenzene
1000 ml of water and 318 gm of 2,4-difluoro nitrobenzene (2,4 DFNB) were charged into a reactor and the reactor was heated to a temperature of 55°C. 493 gm of 50% KOH solution was added slowly in the reactor over a period of 1.5 hrs. under stirring. The stirring was continued further for 4 hrs. to obtain a reaction mass. The reaction was stopped and maintained further for 6 hours.
The reaction was monitored by GLC and worked up to obtain 4-fluoro-2-hydroxy nitrobenzene (purity 99.6% and yield 90%).
Experiment 3: Preparation of 2-ethoxy-4-fluoro nitrobenzene

900 ml DMSO and 303 gm of K2CO3 were charged into a reactor under stirring. 314 gms. of 2-hydroxy- 4-fluoro nitrobenzene was added into the reactor slowly over a period of 30 minutes under stirring. The stirring was continued for a period of 1 hour at 30°C. The mixture so obtained was transferred into SS pressure reactor and 155 gm of ethyl chloride gas was charged into the pressure reactor at 35-40°C. The pressure reactor was heated to 100°C and the temperature was maintained for a period of 2 hrs. The temperature of the pressure reactor was raised to 120°C and maintained further for 4 hrs to obtain a product comprising 2-ethoxy-4-fluoro nitrobenzene. The reaction was monitored by GLC and worked up to obtain 2-ethoxy-4-fluoro nitrobenzene (340 gms; purity 98.4% and yield 90%).
Inorganic Recovery: Inorganic solids (mixture of K2CO3 and KCl) obtained during the Ethoxylation step.
Recovery of K2CO3 and KCl from the mixture obtained from the Ethoxylation step
Wt. of Inorganic Cake taken for treatment = 250 gm.
Analysis : K2CO3 = 2% KHCO3 = 48%, KCl = 50%

250 ml. of water and added 250 gm of inorganic cake were charged into a reactor to obtain a mass. The mass was heated to reflux and stirred at reflux temperature for 1 hr. Distilled out 50 ml. water from the mass and added 50 ml Methanol into mass. The mass was slowly cooled to room temperature and filtered, washed with cold methanol, and dried.
94% of KCl and 89% KHCO3 were recovered.

Experiment 4: Preparation of 2-chloro-4-trifluoromethyl phenol
1500 ml of DMSO was charged into a reactor and 11.37 gm. of Triethyl benzyl ammonium chloride (TEBACl) catalyst was added into it. 395 gm of 85% KOH solids were slowly added into the reactor and the reactor was heated to 70°C. Further, 430 gm of 3, 4 dichloro benzotrifluoride (3,4 DCBTF) was added into the hot reactor over a time period of 2 hrs. at 70-75°C. The temperature of the reactor was further raised to 85°C and stirred for a period of 18 hrs to obtain a reaction mass.
The reaction was monitored by GLC and worked up to obtain 2-chloro-4-trifluoro methyl phenol (Total yield = 66%) and 2-chloro-5-trifluoro methyl phenol (8%).
Experiment 5: Preparation of Oxyfluorfen
600 ml of DMSO and 180 gm of K2CO3 were charged into a reactor to obtain a solution. 200 gm of a mixture of 2-chloro-4-trifluoromethyl phenol and 2-chloro-5-trifluoromethyl phenol obtained from experiment 4 was added into the reactor under stirring for 1 hour at room temperature to obtain a mixture.
185 gm of 2-ethoxy-4-fluoro nitrobenzene obtained from experiment 3 was added to the mixture into the reactor and the temperature of the reactor was raised to 100°C and maintained for a period of 9 hrs to obtain a reaction mass. A first lot of 20 gm of a mixture containing 2-chloro-4-trifluoromethyl phenol was added into the reactor and stirring was continued for a period of 5 hrs.
Further, the second lot of 20 gm of 2-chloro-4-trifluoromethyl phenol was added to the reactor under stirring maintaining for a further period of 4 hours to obtain a product mixture comprising Oxyfluorfen and Oxyfluorfen analogue.
The so obtained product mixture comprising Oxyfluorfen and Oxyfluorfen analogue was purified using a solvent mixture of hexane and toluene (75:25) in a proportion of 2.5 ml/gm to obtain pure Oxyfluorfen. The purity of Oxyfluorfen is 97.5% and the yield was 76%.
Inorganic Recovery from mixture of K2CO3, KHCO3, KF obtained during Oxyfluorfen step.
Wt. of Inorganic Cake taken for treatment = 250 gm.
Analysis : K2CO3 = 40% KHCO3 = 20%, KF = 40% KCl = Neg
250 ml of 80:20 (v/v) mixture of methanol and water was taken into the reactor and added 250 gm of inorganic cake into it. The mixture was heated to reflux temperature and so obtained mass was further refluxed for 1 hr to obtain a reaction mass. The reaction mass was cooled to RT and filtered, washed with cold methanol, dried & finally heated to 200°C, and kept till no CO2 gas evolution.
KF Recovery = 98% K2CO3 Recovery = 78%

TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization and a process for the preparation of Oxyfluorfen, which
- involves an economical and energy saving process;
- allows preparing Oxyfluorfen with comparatively higher purity;
- provides a high yield of Oxyfluorfen; and
- allows recycling of reagents that reduce the cost, and hence environment friendly.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising, will be understood to imply the inclusion of a stated element, integer or step,” or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

,CLAIMS:WE CLAIM:
1. A process for the preparation of Oxyfluorfen represented by formula (I):

(I)
said process comprising the following steps:
a) dissolving at least one weak base in at least one first fluid medium to obtain a solution;
b) adding a first portion of 2-chloro-4-trifluoromethyl phenol to said solution under stirring at a temperature in the range of 25 °C to 35 °C to obtain a mixture;
c) adding 2-ethoxy-4-fluoro nitrobenzene to said mixture and reacting at a first predetermined temperature for a first predetermined time period to obtain a reaction mass;
d) adding at least two portions of 2-chloro-4-trifluoromethyl phenol in said reaction mass at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising Oxyfluorfen and Oxyfluorfen analogue; and
e) purifying said product mixture comprising Oxyfluorfen and Oxyfluorfen analogue by using at least one second fluid medium to obtain pure Oxyfluorfen.
2. The process as claimed in claim 1, wherein said 2-chloro-4-trifluoromethyl phenol contains 2-chloro-5-trifluoromethyl phenol as an impurity.
3. The process as claimed in claim 2, wherein a weight ratio of said 2-chloro-4-trifluoromethyl phenol to said 2-chloro-5-trifluoromethyl phenol is in the range of 80:20 to 85:15.
4. The process as claimed in claim 1, wherein said first portion of 2-chloro-4-trifluoromethyl phenol is in an amount in the range of 70 wt% to 85 wt% with respect to the total weight of 2-chloro-4-trifluoromethyl phenol.
5. The process as claimed in claim 1, wherein a weight ratio of said at least two portions of 2-chloro-4-trifluoromethyl phenol is further added in an amount in the range 5 wt% to 30 wt% independently for each portion with respect to total weight of 2-chloro-4-trifluoromethyl phenol.
6. The process as claimed in claim 1, wherein said first fluid medium is selected from the group consisting of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and N-Methyl pyrrolidone (NMP).
7. The process as claimed in claim 1, wherein said weak base is selected from the group consisting of potassium carbonate, sodium carbonate, and calcium carbonate.
8. The process as claimed in claim 1, wherein said first predetermined temperature is in the range of 90 °C to 120 °C.
9. The process as claimed in claim 1, wherein said first predetermined time period is in the range of 3 hours to 9 hours.
10. The process as claimed in claim 1, wherein said second predetermined temperature is in the range of 90°C to 120°C.
11. The process as claimed in claim 1, wherein said second predetermined time period is in the range of 3 hours to 15 hours.
12. The process as claimed in claim 1, wherein a molar ratio of said 2-ethoxy 4-fluoro nitrobenzene to said 2-chloro-4-trifluoromethyl phenol is in the range of 1:1.1 to 1:1.5.
13. The process as claimed in claim 1, wherein said second fluid medium is selected from hexane and toluene.
14. The process as claimed in claim 1, wherein said second fluid medium is a mixture of hexane and toluene in the range of 70:30 to 80:20.
Dated this 07th day of October, 2021

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI