PROCESS FOR PREPARING OF N-METHYL PYRROLIDONE

摘要

The present invention relates to a process for preparation of N-methyl pyrrolidone, and more particularly to a process for preparing high purity, high yield N-methyl pyrrolidone, comprising a first step of dehydrogenating 1,4-butandiol under a hydrogen atmosphere in the presence of a metal oxide solid catalyst to prepare ?-butyrolactone, and a second step of subjecting the ?-butyrolactone obtained in the first step without purification to a dehydration with monomethylamine under a metal oxide solid catalyst. The process for preparation of N-methyl pyrrolidone according to the present invention is a continuous two-step process using a metal oxide catalyst, wherein the second step continuously progresses without purification of the reaction product of the first step, ?-butyrolactone. According to the present invention, little of a reaction intermediate ?-butyrolactone, which is difficult to separate because of a small difference in boiling point (about 2 "C) from the final product, N-methyl pyrrolidone, remains after reaction, and thus separation and purification are easy. Further, its simple process enables mass production and lowers purification equipment cost.