Claims:
1. A one pot process for preparing chloro-hydroxy derivative, the process comprising
treating a substituted amino compound with an acid to form an amine salt followed by addition of diazotizing agent in the presence of a solvent to obtain an effluent phase and an organic phase comprising chloro-hydroxy derivative.

2. The process as claimed in claim 1 further comprising recovering the acid from effluent phase and solvent from organic phase and recycling the acid and solvent to react with the substituted amino compound.

3. The process as claimed in claim 1 further comprising reacting the effluent phase with lime to form calcium chloride.

4. The process as claimed in claim 1 comprising recovering chloro-hydroxy derivative from the organic phase by fractional distillation.

5. The process as claimed in claim 1 comprising treating substituted amino compound with an acid at a temperature in a range of 35° to 80°C.

6. The process as claimed in claim 1 comprising treating the amine salt with a diazotizing agent at a temperature in a range of 30° to 80°C.

7. The process as claimed in claim 1, wherein the ratio of substituted amino compound and acid is 1: 10 to 1: 15

8. The process as claimed in claim 1, wherein the concentration of the acid is in a range of 15% to 30%.

9. The process as claimed in claim 1, wherein the substituted aromatic amino compound is selected from the group comprising of mono or di alkyl substituted aniline, preferably m-toluidine.

10. The process as claimed in claim 1, wherein the acid is selected from hydrochloric acid, hydrobromic acid,hydroiodic acid,preferably hydrochloric acid.
11. The process as claimed in claim 1, wherein the diazotizing agent is selected from nitrogen oxide component, sodium nitrite, nitrosyl sulfuric acid and sulfuric acid , nitrosyl sulfuric acid and acetic acid, nitrosyl chloride, preferably sodium nitrite.

12. The process as claimed in claim 1, wherein the solvent is polar and nonprotic.

13. The process as claimed in claim 12, wherein the solvent is selected from ethyl acetate, acetone , methyl isobutyl ketone , methyl ethyl ketone.

14. A process for preparing a mixture of m-chloro toluene and m-cresol, the process comprising
treating m-toluidine with hydrochloric acid in the presence of methyl isobutyl ketone to form an amine salt followed by addition of sodium nitrite to obtain an effluent phase and an organic phase comprising a mixture of m-chloro toluene and m-cresol.

15. The process as claimed in claim 14, comprising separating the effluent phase and organic phase.

16. The process as claimed in claim 15, wherein the effluent phase is treated with lime to form calcium chloride and recovering and recycling hydrochloric acid and methyl isobutyl ketone to the process step of reacting with m-toluidine.
, Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]

A ONE POT PROCESS FOR PREPARING CHLORO-HYDROXY DERIVATIVE;

DEEPAK NITRITE LIMITED, A COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956 WHOSE ADDRESS IS 9/10, KUNJ SOCIETY, R C DUTT ROAD, ALKAPURI, VADODARA, GUJARAT; 390007 INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF INVENTION
The present invention relates to a one pot process for preparing chloro-hydroxy derivative.

BACKGROUND OF THE INVENTION
Meta-chloro toluene and meta-cresol are important intermediate products for the production of agrochemicals and pharmaceuticals.

Bulletin of the Institute for Chemical Research, Kyoto University, Volume: 20, Pages: 62-3, Journal, 1950 discloses synthesis of meta chloro toluene using diazonium salt-ZnCl2 double salt from meta toluidine refluxed in a suitable solvent .

Journal of the Chemical Society, Pages: 745-6, Journal, 1946 discloses decomposition of diazonium salts by cupric chloride in neutral and acid solution wherein conversion of m-toluidine to meta-chloro toluene is very low(7% in neutral and acid solution)
Russian Journal of Organic Chemistry, Volume: 48, Issue: 8, Pages: 1055-1058discloses synthesis of mono chlorotoluene from meta toluidine using CuCl; CuCl2 in the presence of catalyst.

Organic Process Research & Development, 7(5), 762-768; 2003discloses synthesis of mono chloro toluene from meta toluidine using anhydrous copper (II) chloride in presence of solvent.

Russian Journal of Organic Chemistry (Translation of ZhurnalOrganicheskoiKhimii), Volume: 38, Issue: 1, Pages: 38-46, Journal, 2002 discloseschloroarylation of unsaturated compounds with arenediazonium chlorides in the presence of CuCl2 as catalyst and involves intermediate formation of arenediazoniumtetrachlorocuprates(II) wherein in polar solvents arenediazoniumtetrachlorocuprates(II) are converted into chloroarenes.

Tetrahedron Letters, Volume: 39, Issue: 51, Pages: 9567-9570, Journal, 1998 disclosesCu-catalyzed reactions of arenediazonium chlorides with unsaturated compounds,arenediazoniumtetrachlorocuprates(II) are formed as intermediates wherein in polar solvents these salts undergo chlorinativedediazoniation to give chloroarenes.

The above processes for production of meta-chloro toluene requires the use of cuprous chloride, which is expensive as well as the large-scale disposal of aqueous copper waste significantly increases the production costs and has harmful impact on environment. Furthermore, in many cases the resulting diazonium salts are of low solubility in the aqueous medium. Hence, the handling of residual diazonium salt solid in the diazotation vessel after the diazotation step is a challenging task.

A reversed addition scheme that is adding an acidic cuprous chloride solution to the diazonium salt mixture is not well suited for large-scale production because of heat generation and gas formation, which are both difficult to control.

Also, addition of diazonium salt solution in cuprous chloride solution at 0°C-5°Crequires more utility to control temperature. Also, during the passing of solid diazonium salt from one reactor to another reactor, the diazonium salt decomposes quickly causing inconvenience and safety concerns. These traditional routes suffer from the disadvantages of high capital cost, utility cost and safety issues.

Traditionally, the known processes have been found to be very unsatisfactory with respect to metal containing effluent treatment and also the disposal cost is very high.
Therefore, there is a need for a process to prepare chloro-hydroxy derivative in high yields and of good quality.

SUMMARY OF THE INVENTION
An aspect of the present invention relates to a one pot process for preparing chloro-hydroxy derivative. The process comprises of reacting a substituted amino compound with an acid to form an amine salt. This is followed by addition of a diazotizing agent in the presence of a solvent to obtain an effluent phase and an organic phase, which comprises of chloro-hydroxy derivative. The process further comprises of recovering acid from effluent phase and solvent from the organic phase and recycling acid and solvent to react with the substituted amino compound.

DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention relates to a one pot process for preparing chloro-hydroxy derivative. The process comprises of treating substituted amino compound with an acid to form an amine salt. A diazotizing agent is added to the amine salt in the presence of a solvent to obtain an effluent phase and an organic phase, which comprises of chloro-hydroxy derivative. The process further comprises of recovering and recycling acid and solvent from the effluent phase and organic phase to the first step of treating substituted amino compound with acid and solvent.

Acid and solvent are recovered by atmospheric distillation.

The chloro-hydroxy derivative is recovered from the organic phase by fractional distillation.

The effluent phase can be treated with lime to form calcium chloride.

The substituted amino compound is selected from mono or di alkyl substituted aniline. Preferably,m-toluidine is used in the reaction.

Acid used in the reaction is a halogen acid selected from hydrochloric acid, hydrobromic acid, hydroiodic acid. Preferably, hydrochloric acid is used in the reaction.

The diazotizing agent is selected from nitrogen oxide component, sodium nitrite, nitrosyl sulfuric acid, nitrosyl sulfuric acid and sulfuric acid, nitrosyl sulfuric acid and acetic acid, nitrosyl chloride. Preferably, sodium nitrite is selected as the diazotizing agent. The ratio of substituted diamino compound to diazotizing agent used is 1:1 to 1:1.05.

The solvent used in the reaction is polar and nonprotic and is selected from ethyl acetate, acetone, methyl isobutyl ketone and methyl ethyl ketone.

The reaction between substituted amino compound and acid is carried out at a temperature in the range of 35°C to 80°C.

The amine salt is treated with a diazotizing agent at a temperature in the range of 30°C to 80°C.

The ratio of substituted amino compound and acid is 1:10 to 1:15.

The concentration of acid is in the range of 15% to 30%.

In a preferred embodiment of the present invention, a process for preparing a mixture of m-chloro toluene and m-cresol comprises of treating m-toluidine with hydrochloric acid in the presence of methyl isobutyl ketone to form an amine salt, which is further treated with sodium nitrite to obtain an effluent phase and an organic phase comprising a mixture of m-chloro toluene and m-cresol. The effluent and organic phase are further separated.

The effluent phase can be treated with lime to obtain calcium chloride.

Hydrochloric acid is recovered from the effluent phase and methyl isobutyl ketone is recovered from the organic phase. Hydrochloric acid and methyl isobutyl ketoneare recovered by atmospheric distillation and are recycled to the process step and treated with m-toluidine.

The process of the present invention obviates the use of cuprous chloride/sodium chloride, which arehazardous to environment for preparing meta-chloro toluene and m-cresol.

The present invention relates to a one pot process for preparing valuable intermediates meta-chloro toluene and m-cresol.

The present invention comprises recovery of acid and recycling to the process step thereby reducing acid consumption significantly.
The following example illustrates the invention, but is not limiting thereof.

Example 1
To a round bottom flask with a scrubber system, 4822 g of 30% aqueous solution of hydrochloric acid and water (958 gm) was charged. 321g of m-toluidine was added at room temperature slowly into the flask under stirring to obtain aqueous solution of hydrochloric salt of m-toluidine. The methyl isobutyl ketone (1300gm) was added to hydrochloric salt of m-toluidine and heated to60°Cwhile stirring. Sodium nitrite solution (obtained by dissolving 219 g of sodium nitrite in 328 g water) was slowly added within 5 hrs, maintaining the temperature at 60°C.The reaction mass was further stirred for 1hrat 60°C to obtain an organic phase comprising meta chloro toluene and meta cresol and an effluent phase. The organic phase was separated from the effluent phase. The effluent layer was recycled and reacted with lime for synthesis of calcium chloride. Methyl isobutyl ketone and hydrochloric acid were recovered from organic phase and effluent phase respectively and recycled to the step of reaction with m-toluidine. Fractional distillation of organic phase was carried out to separate m-chloro toluene (101gm; 99.5% purity) and m-cresol (121g;99.5% purity). Overall Yield was 80%.