| 1. | Using ethyl cyanoacetate , triethyl orthoformate and methylhydrazine as main raw materials , the herbicide pyrazosulfuron was prepared through the reactions of substitution , amination , cylclization , diazotization and chlorosulfonation 摘要以氰乙酸乙酯、原甲酸三乙酯和甲肼等为主要原料,通过取代、胺化、环化、重氮化和氯磺化等反应制得了除草剂吡嘧磺隆原料药。 |