Three pyrazole acyl chloride derivatives were synthesized with ethyl 3-phenyl-1H-pyrazole- 5-carboxylate as starting materials. Six kinds of 1,3,4-thiadiazole derivatives were received from substituted carboxylic acids and thiosemicarbazide with phosphorus oxychloride as dehydrating agent. Pyrazole and 1,3,4-thiadiazole were connected together through acylamidation reaction and 18 target compounds were synthesized, which have not been reported in the literatures. All the new compounds were confirmed by means of elemental analysis, IR and NMR spectra. Besides, primary biological activity experiments have been done. It is found from the results that the activities of the target compounds were not high, even some were antiblastic to wheat gemma. But the germination rate of mung bean test results showed that all the tar-get products of the mung bean sprout processes all have a catalytic role.

Key words: pyrazole, 1,3,4-thiadiazole, synthesis, biological activity