Synthesis And Herbicidal Activities Of1-PYRAZOL-5’-YLCATBONYL-4-Arylsemicarbazide

Recently pyrazolyl and hydrazinecarboxyamide derivatives are widely studied in the pesticide fields in order to find out new pesticide lead compounds for their good biological activities. In this research pyrazolyl derivatives were used as main group to synthesis hydrazide pyrazole derivatives. Then38new pyrazolyl hydrazinecarboxyamide derivatives are synthesized from the hydrazide pyrazole derivatives and substituted phenyl isocyanate. Their structures were confirmed by1H NMR, FTIR, MS and elemental analysis. The herbicidal activities of these compounds were evaluated. The main contents are listed as follows:1.1-Methy1-3-ethy1-5-pyrazole hydrazide and1-methyl-3-ethyl-4-nitro-5-pyrazole hydrazide were obtained with diethyl oxalate,2-butanone and hydrazine hydrate as starting material by Claisen condensation reaction, knorr cyclization, condensation and other reactions. 2. Substituted phenyl isocyanates are synthesized from substituted aniline and BTC. Compared with the method of using chloroformyl chloride, BTC is safe and mild reaction conditions.3.38new pyrazolyl hydrazinecarboxyamide derivatives were synthesized from the two pyrazole hydrazide intermediates and substituted phenyl isocyanate. Their structures were confirmed by IR, MS,’HMR and elemental analysis.4. The results of herbicidal activity tests indicated that,1-(4-bromo-pyrazoloyl)-4-substituted phenylsemicarbazide might be lead compound, and their structure-activity relationship was studied.