Epoxidation In The Pharmaceutical, Pesticide Synthesis

Oxirane, as an important intermediate, is widely used in the synthesis of pharmacon and pesticide. Preparation of Oxirane by condensation of carbonyl compound and sulphur ylide is a quick and important synthetic method because the materials are cheap and easy to obtain. Moreover, the reaction has a few by-products. (CH3)3S+CH3SO4- and (CH3)3S+HSO4- were chosen as the epoxy reagent to react with carbonyl compounds in this paper. The ring-opening reaction of oxiranes were also studied.(CH3)3S+CH3SO4- was synthesized from (CH3)2S and (CH3)2SO4.The process conditions were studied. It was the first time to synthesize 2-(6-methoxynaphthyl)-1,2-epoxypropane as intermediates of Naproxen using 6-methoxy-2-acetylnaphthal-ene and (CH3)3S+CH3SO4-. Then, 2-(6-methoxynaphthyl)-1,2-propandiol was obtained by hydrolyzation of the epoxide under acidity condition,the total yield was 88. 7%.(CH3)3S+HSO4- was synthesized from (CH3)2S , CH3OH and H2SO4. The reaction condition was studied. 1-(2,4-dichlorophenyl)-2-imidazoly-ethanol, the key intermediate of miconazole and econazole, was prepared from 2,4-di--chlorobenzaldehyde for the first time. 2,4-dichlorobenzaldehyde can react with (CH3)3S+HSO4-, optionally with (CH3)3S+CH3SO4-, as well as base to produce 2,4-dichlorophenyloxirane. Then the epoxide react with imidazole under alkali condition to obtain 1- (2,4-dichlorophenyl)-2-imidazolylethanol, the total yield was 54.6%.4-(4-chlorophenyl)-2-(t-butyl)-l,2-epoxybutane was prepared by epoxidation of l-(4-chlorophenyl)-4,4-dimethlyl-3-pentanone with (CH3)3S+CH3SO4-.The epoxide react with 1,2,4-triazole in autoclave under alkali condition to obtain tebuconazole.The total yield was 77. 6% and purity of the product was 95.2% which all were higher than previous reports.It was the first time to synthesize hexaconazole through epoxidation of 2,4-dichIorophenylpentanone and condensation of 2-(2,4-dichlorophenyl)-l,2-epoxy-hexane with 1,2,4-triazole in autoclave under alkali condition, the total yield was 80. 3% . The pathway can be applied in industry.