SU447039A1 - Method for producing 2,5-dimethyl-4-piperidone - Google Patents

Description

This invention relates to an improved process for the preparation of 2,5-dimethyl-4-pi peridone, an intermediate product for the synthesis of biologically active compounds. A known method for the preparation of 2,5-di methyl-4-piperidone is that diytilvinyl ethynyl carbinol is treated with sulfuric acid, the resulting vinyl propane acetylene is hydrated in aqueous methanol in the presence of mercuric acid sulfuric acid and sulfuric acid, followed by cyclization of the ally proopenyl ketone mixture and corresponding methoxy dosage. ammonia solution. Yield 11%. The proposed method for producing 2,5-dimethyl-4-piperidone is characterized by simplicity and higher yield of the crude product. The method consists in that 1,2,5-trimethyl-4-piperidone is reacted with chlorotic acid ethyl ester in an inert solvent, for example benzene, while heating, for example, at the boiling point of the reaction mixture. The resulting 1-carbethoxy-2,5-dimethyl-4-piperidone is subjected to acidic hydrolysis. The desired product is isolated in a known manner. Exit 40.6 /. Example. Preparation of 2,3-diethyl-4-piperidone (III). To a boiling solution of 35.3 g (0.25 mol) of freshly distilled technical 1,2,5-trimethyl-4-piperidone (I) in 100 ml of absolute benzene with vigorous stirring, 81.4 g (0, 75 mol) chloroic acid ethyl ester. In this case, the observed-g