PROCESS FOR PREPARING DERIVATIVES OF THE 7BETA-AMINO-3-CEFEM-3-OL-4-CARBOXYLIC ACID

摘要

This invention is directed to a process for the preparation of a 2-alkoxycarbonylamino-5(6)-phenylsulfonyloxy-benzimidazole of the formula (1) (1) wherein R1 represents alkyl of 1 to 4 carbon atoms, R2 and R3, independently of one another, each represents hydrogen, hydroxy, alkoxy of 1 to 4 carbon atoms, halogen, trifluoromethyl, alkyl of 1 to 4 carbon atoms, alkoxycarbonyl of 1 to 4 carbon atoms in the alkoxy radical, or cyano by the reaction of a 2-alkoxycarbonyl-amino-5(6)hydroxybenzimidazole with a benzene-sulfonic acid halide in the presence of a base. The products are valuable chemotherapeutic agents suitable for combatting diseases caused by parasites in humans and animals such as helminths and liver flukes.