Convenient Method for the Preparations of Carboxylic Thiolester and Acid Anhydride

Abstract

Abstract The reactions of mercuric carboxylates with bivalent sulfur compounds, such as aralkyl sulfides and mercaptoles, were investigated. When mercuric acetate and aralkyl sulfides were refluxed in benzene, mercury mercaptides and aralkyl acetates were obtained. It was made clear that the reactivity of the sulfides depends on the stability of carbonium ions given by elimination of the mercapto group. Next, it was found that acetic anhydride, benzophenone and mercury phenylmercaptide were obtained in high yields by the equimolar reaction of benzophenone diphenylmercaptole with mercuric acetate. Further, the reaction was extended to the preparative method of carboxylic acid anhydrides from free acids by treating the carboxylic acids with diphenylmercury and the mercaptole. On the other hand, S-phenyl thioacetate, benzophenone and mercury mercaptide were produced in good yields when benzophenone diphenylmercaptole (2 mol) was treated with mercuric acetate (1 mol). Further, it was established that thiolesters were exclusively produced in good yields along with benzophenone and the mercury mercaptide by the reaction of benzophenone diphenylmercaptole or bis (p-chlorophenyl) mercaptole (2 mol) with free carboxylic acids (2 mol) and diphenylmercury (1 mol).