Research On Synthesis Of Pyrimisulfuron-Methyl

This thesis carries on the reseach of synthesis of herbicide of primisulfuron-methyl.This thesis points out the advantages and shortages comparing with a single-step and a multi-step process, affirms the single-step process which can prepare the intermidiate 2-amino-4,6-bis(difluoromethoxy)pyrimidine by difluoromethylation of 2-amino-4,6-dihydroxypyrimidine, and describes the reaction mechanism. It also explores the optimum reaction conditions in industrial process, and raises the yield.The author finds out a non-isocyanate process which can conveniently prepare the sulfonylurea derivatives in a simple manner. As a result the author argues that there is a novel single-step method capable of preparing the sulfonylurea derivatives in a high purity and in a high yield. The method can secure against of using phosgene, reduce pollution, simplify process, lessen investement, save energy, protect environment. It is a green chemical method for preparation of sulfdfiylurea derivatives.During the experiments, the structures of compounds which have been synthesized were confirmed by IR, 1HNMR and 13CNMR. The compounds' content was measured by HPLC.