Oxidation of organic sulphide(s) to corresponding sulphone(s) - using hydrogen peroxide, a carboxylic acid and a mineral or sulphonic acid catalyst

摘要

An organic sulphide is oxidised to the corresponding sulphone with a mixture of H2O2 and a carboxylic acid in the presence, as a catalyst, of a mineral acid or an organic sulphonic acid. The process gives higher yields of sulphone (e.g. 66-90%) than are obtd. in the known process performed in the absence of acid catalyst (e.g. 34%) with less formation of sulphoxide by-product (generally is approx. 0.1% if a sufficient quantity of acid catalyst is used as opposed to e.g. 15% in the absence of a catalyst). The sulphone products have a wide vareity of uses e.g. as insecticides, miticides and nematocides. In a typical example, 2-methyl-2-methylthio-propionaldehyde O-(methylcarbomoyl)-oxime is oxidised to the corresp. sulphone using H2O2 and formic acid in CH2Cl2 contg. concd. H2SO4.