PROCESS FOR THE PREPARATION OF 2-(TRIHALOMETHYL) BENZAMIDE

Abstract

The present invention relates to a process for preparation of 2-(trihalomethyl) benzamide.

Claims

1. A process for the preparation of 2-(trihalomethyl) benzamide of Formula I, ##STR00010## wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, said process comprising: a) reacting a compound of Formula II with a compound of Formula III in the presence of iso-propanol to obtain a reaction mixture; and ##STR00011## wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, b) isolating the compound of Formula I from the reaction mixture.

2. The process as claimed in claim 1, wherein the reaction is carried out at a temperature in the range of about 75 C. to about 25 C.

3. The process as claimed in claim 1, wherein the reaction is carried out at a time period in the range of about 10 minutes to about 6 hours.

4. The process as claimed in claim 1, wherein the compound of Formula I is isolated by a process selected from the group consisting of filtration, precipitation, decantation, crystallization, evaporation, layer separation and distillation or a combination thereof.

5. The process as claimed in claim 1, wherein the reaction mixture is stirred to facilitate the reaction.

6. A process for the preparation of 2-(trihalomethyl) benzamide of Formula I, ##STR00012## wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, said process comprising: (i) reacting a compound of Formula II with a compound of Formula III in the presence of cold water to obtain a reaction mixture; and ##STR00013## wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, ii) isolating the compound of Formula I from the reaction mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention provides a process for preparation of 2-(trihalomethyl) benzamide of Formula I,

##STR00006## [0023] wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, [0024] said process comprising; [0025] a) reacting a compound of Formula II with a compound of Formula III in the presence of iso-propanol to obtain a reaction mixture; and

##STR00007## [0026] wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/un-substituted C.sub.1-C.sub.7 alkyl group, [0027] b) isolating the compound of Formula I from the reaction mixture.

[0028] The present invention also provides a process for the preparation of 2-(trihalomethyl) benzamide of Formula I,

##STR00008## [0029] wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, [0030] said process comprising; [0031] (i) reacting a compound of Formula II with a compound of Formula III in the presence of cold water to obtain a reaction mixture; and

##STR00009## [0032] wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; and R is hydrogen or substituted/unsubstituted C.sub.1-C.sub.7 alkyl group, [0033] (ii) isolating the compound of Formula I from the reaction mixture.

[0034] The compound of Formula II is prepared by any method known in the art, for example, as provided in Indian Patent Application no. 3476/DEL/2011. The reaction of compound of Formula II with compound of Formula III in iso-propanol or cold water takes place at a temperature in the range of about 75 C. to about 25 C., for a time period in the range of about 10 minutes to about 6 hours. The compound of Formula III may be in liquid form or in gaseous form. The reaction mixture may be stirred to facilitate the reaction. The compound of Formula I is isolated by filtration, precipitation, decantation, crystallization, evaporation, layer separation and distillation or a combination thereof.

[0035] The compound of Formula I, obtained by the present invention, has a purity greater than about 98%, for example, greater than about 99% by HPLC.

[0036] The compound of Formula I, obtained by the present invention, is used for preparation of various agrochemical and medicinal products.

[0037] While the present invention has been described in terms of its specific embodiments, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.

Example

Preparation of 2-(Trifluoromethyl) Benzamide

[0038] a) 2-Trifluoromethyl benzoyl chloride (50 g) and iso-propanol (400 g) were taken in a reaction vessel and ammonia gas was purged into it. The reaction was allowed to stir for 3.5 hours at a temperature in the range of 10 C. to 0 C. to facilitate the reaction. The ammonium chloride was precipitated out and the reaction mixture was filtered to obtain a filtrate. The filtrate was concentrated to obtain the compound of Formula I.

[0039] Yield: 90%

[0040] Purity (% by HPLC): 99% [0041] a) 2-Trifluoromethyl benzoyl chloride (20 g), cold water (20 g) and ammonium hydroxide (aqueous ammonia) (19.6 g) were taken in a reaction vessel and the temperature was maintained at 10 C. The reaction was allowed to stir for 3.5 hours to facilitate the reaction. The reaction mixture was then filtered and washed with water. The filtrate was concentrated to obtain the compound of Formula I.

[0042] Yield: 90.6%

[0043] Purity (% by HPLC): >99%