In order to realize combination of multiform active ingredients and supply lead compound for drug screening, eight novel N-substituted benzothiazol-2-yl-amino-N′-substituted pyrazol-4-yl-carbonylthiourea derivatives were prepared by the reaction of substituted benzothiazol-2-ylhydrazines with substituted pyra-zol-4-ylcarbonyl isothiocyanates. The intermediates, 1-phenyl-3-methyl-5-chloro/phenoxyl pyrazol-4-ylcarbonyl chloride and 1-phenyl-3-methyl-5-chloro/phenoxyl pyrazol-4-ylcarbonyl isothiocyanate, were synthesized by using 1-phenyl-3-methyl-5-chloro/phenoxyl pyrazole-4-carboxylic acid as starting material. The synthetic process was carried out both under ultrasound and under heating. After comparison, it was found that the process under ultrasound had many merits with excellent yield, short time, simple operation and less secondary reaction. Their structures were confirmed by IR, ¹H NMR spectra and elemental analysis.

Key words: pyrazole, synthesis, benzothiazole, ultrasound, thiosemicarbazide