Abstract
Acyl chlorides reacted with ammonium thiocyanate and carbonic dihydrazide under phase‐transfer catalysis to first afford 2,2′‐bis(acylaminothiocarbonyl)‐carbonic dihydrazides, which further cyclized in the presence of glacial acetic acid to efficiently give 1‐(5′‐acylamino‐1′,3′,4′‐thiadiazol‐2′‐yl)‐4‐acyl‐thiosemicarbazides in high yield.
Acknowledgment
The authors thank the Chunhui Project of Ministry of Education of China (Z2004‐1‐62034) for the financial support of this work.