反应详情

The procedure used was as described in Example 5. However, there were used 9.2 g of 2-amino-5-piperidino-1,3,4-thiadiazole, 8.5 g of diethyl acetylenedicarboxylate and 200 ml of ethanol. Thus 9.8 g (63.7% of the theoretical yield) of ethyl 2-piperidino-7H-1,3,4-thiadiazolo-[3,2-a]-pyrimidin-7-one-5-carboxylate, melting at 125° to 127° C., were obtained.