THE SYNTHESIS AND BIOLOGICAL-ACTIVITY OF 1-ARYL-4-SUBSTITUTED PYRAZOLOYL THIOSEMICARBAZIDES AND RELATED HETEROCYCLIC-COMPOUNDS

A series of new acylthiosemicarbazide derivatives (III) were synthesiz ed by addition reaction of 1-phenyl-3-methyl-5-chloro-4-pyrazoloyl iso thiocyanate (I) with aroyl hydrazines (II), which were cyclized under an acidic condition to obtain 2-substituted pyrazoloyl amino-5-aryI-1, 3,4-thiadiazoles (IV), The preliminary biological tests indicate that some compounds of III and IV show a good herbicidal activity.