Design, synthesis, and herbicidal activity of novel pyrimidine derivatives containing 1,2,4-triazole

A facile approach for the synthesis of pyrimidine derivatives containing 1,2,4-triazole moiety via the reaction of substituted 2-phenoxypropane hydrazide with ethyl-N-(5-cyano-2-alkylthio-5-cyano-6-methylthiopyrimidin-4-yl) formimidate in refluxing 2-methoxyethanol is reported. The structures of the title compounds were identified by 1H NMR, 13C NMR, and HRMS. The configuration of compound 5a was confirmed by X-ray crystallography analysis. The preliminary herbicidal test indicated that some of the target compounds exhibited good inhibition activities against Brassica napus (rape) and Echinochloa crusgalli (barnyard grass).