Ammonia → 7-Amino-3-(2-ethoxycarbonylmethylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A 8.0 ml portion of acetonitrile was added to 1.36 g of 7-ACA and 1.54 g of 2-ethoxycarbonylmethylthio-5-mercapto-1,3,4-thiadiazole, and the mixture was cooled to -40° to -30° C., followed by adding thereto dropwise 5.40 g of DCPA under stirring. The external bath was removed and the reaction mixture was stirred for 8 minutes, then warmed at 40° C. and stirred for 20 minutes to allow the reaction to proceed. The reaction solution was poured into 10 ml of ice-water, which was adjusted to pH 4.4 with 25% aqueous ammonia. The precipitated powder was recovered by filtration, washed with water and dried, thereby affording 2.08 g (92.7% of yield) of 7-amino-3-[(2-ethoxycarbonylmethylthio-1,3,4-thiadiazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid in the form of mud yellow powder.

Provenance & Evidence