5-chloro-2-pentanone preparation method

The present invention provides a 5-chloro-2-pentanone preparation method, which comprises that: 2-methyl furan is subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst and hydrogen gas to prepare 2-methyl-4,5-dihydrofuran, and the 2-methyl-4,5-dihydrofuran and hydrochloric acid are subjected to a ring opening chlorination reaction to obtain the 5-chloro-2-pentanone. According to the present invention, 2-methyl furan is adopted as the raw material, the reaction steps are simple and easy to operate, no wastewater is generated during the production process, and environmental protection requirements are met; the hydrogenation catalyst, the distillate and the hydrochloric acid can be recycled so as to substantially reduce the production cost, and the prepared product has characteristics of high yield and high purity; and compared with the conventional process, the preparation method of the present invention has characteristics of complete elimination of influence of hydrochloric acid on