33 g of α-chloro-α-(4-methoxybenzoyl)-2-chloro-5-dodecyloxycarbonylacetanilide and 16 g of 1-(4-carboxyphenyl)-5-mercaptotetrazole were dispersed in 200 ml of chloroform to which was added dropwise 10 ml of triethylamine at room temperature over a period of about 30 minutes. After stirring for 3 hours the chloroform solution was washed with water and concentrated under reduced pressure. The residue was recrystallized from methanol to obtain 41.2 g of α-(4-methoxybenzoyl)-α-[1-(4-carboxyphenyl)-5-tetrazolylthio]-2-chloro-5-dodecyloxycarbonylacetanilide. Yield: 93%. Melting Point: 172° to 174° C.
