Abstract:

Ethyl 3-(4-methoxy phenyl)-1H-pyrazole-5-carboxylate was synthesized by means of one-pot reaction method; and two kinds of pyrazole carboxylic acid were obtained through methylation at position 1, chlorination at position 4 and hydrolysis. Six 5-substituted-2-amino-1,3,4-thiadiazoles were obtained from substituted carboxylic acids and thiosemicarbazide using phosphorus acylchloride as the dehydrating agent. Pyrazole and 1,3,4-thiadiazole were connected together by amido bond and 12 new compounds were synthesized. The yield of the title compounds was up to 50%. All the new compounds were confirmed by means of elemental analysis, IR and 1H NMR spectroscopies. Their auxin activities are not high, and a few of them are antiblastic to wheat gemma.

Key words: pyrazole, thiadiazole, synthesis