Selective Reduction Of Nitro-Compounds To Primary Amines By Ni/Silane And The Double Michael Reaction Of The 3,4-Dihydropyrimidinones

Primary amines are important intermediates of medicines and agricultural chemicals. The best way to obtain primary amines is the reduction of nitro-compounds. Although there are kinds of way to reduce the nitro group, the obvious disadvantages could not be ignored such as the harsh reaction conditions,pollutions and the low chemoselectivity. Over the last decades, silanes have appeared to be new potential reducing agents for the reduction of nitro-compounds because of their significant advantages such as mild conditions, high chemoselectivity and stability of air and moisture.3,4-Dihydropyrimidinones(DHPMs) have good biological and pharmacological activities. They could be used as antihypertensive agents, potent calcium channel blockers and neuropeptide Y antagonists. Because of these, investigation of new functionalzed DHPMs has always been advocated, scientists not only study the application of the DHPMs, but also make them modified and functionalized.According to our previous work, the Michael reactions of DHPMs with methyl acrylate were summarized in this thesis.The specific research contents and results were described as follows:1. we demonstrated an efficient and convenient protocol for the catalytic reduction of many kinds of nitro-compounds using Polymethylhydrosiloxane(PMHS)in the presence of Ni(acac)2 catalysts.2. N1,N3-(2-acetyl-ethyl) fuctionalized 3,4-dihydropyrimidine-2-ones were efficiently synthesized using Michael reactions catalyzed by Cs2CO3 with PEG-400 as the solvent.All the products were characterized by 1H NMR, 13 C NMR and HRMS spectroscopic analysis.