Hetero Drugs Limited

Hetero Labs Limited

Nagabelli Murali

Kura Rathnakar Reddy

Bandi Parthasaradhi Reddy

Dasari Muralidhara Reddy

Rapolu Raji Reddy

Nimmanapalli Pullareddy

A process is disclosed for preparing sartan drugs including intermediates thereof, which avoids formation of Nitrosoamine impurities.

Process for the preparation of angiotensin II receptor blockers

There is provided an improved process for preparing cefixime. Thus, for example, 7-amino-3-vinyl-3-cephem-4-carboxylic acid is reacted with 2-mercapto-1,3-benzothiazolyl-(Z)-2-(2-aminothiazol-4-yl)-2-(methoxycarbonyl)-methoxyimino acetate in tetrahydrofuran and water at 4&#xb0; C. in the presence of triethylamine. The reaction mass is extracted with ethyl acetate. 7-[2-(2-Amino-4-thiazolyl)-2-(methoxycarbonylmethoxyimino)acetamido]-3-vinyl-3-cephem-4-carboxylic acid triethylamine salt present in the aqueous layer is hydrolyzed with sodium hydroxide in less than 30 minutes and aqueous hydrochloric acid is added immediately to adjust the pH to 4.8 to 5.2. Then, aqueous hydrochloric acid is added at 35&#xb0; C. to adjust the pH 2.5 and cooled to crystallize cefixime trihydrate in high purity.

Process for the preparation of cefixime

The present invention relates to a process for preparing a key intermediate of cefprozil and use of this intermediate in the preparation of cefprozil thereby avoiding impurity-causing self-acylation. [R-(Z)]-[4-hydroxy-&#x3b1;-[(3-methoxy-1-methyl-3-oxo-1-propenyl)amino]] benzeneacetic acid, mono potassium salt is reacted with ethyl chloroformate to obtain mixed anhydride which is then silylated with N,O-bis(trimethylsilyl)acetamide. The silylated compound obtained is reacted with [7-trimethylsilylamino-3-(Z/E-propen-1-yl)-3-cephem-4-carboxylic acid]trimethylsilyl ester and deprotected with aqueous hydrochloric acid to give cefprozil.

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Hyderabad Telangana, India

Nagabelli Murali