Process for producing lactam

摘要

It is an object of the present invention to provide an efficient method of continuously producing a lactam in high-temperature high-pressure water, and the present invention relates to a method of producing a lactam characterized by efficiently synthesizing the lactam while suppressing oxime hydrolysis by introducing an oxime as a reaction substrate and an acid into a reaction zone through which high-temperature high-pressure water is flowing, or introducing an oxime into flowing high-temperature high-pressure water containing an acid, thus raising the temperature of the reaction substrate to put the reaction substrate into a prescribed high-temperature high-pressure state within a short time and subjecting the reaction substrate to reaction; through the method, the lactam can be efficiently and continuously synthesized at a high rate from the oxime using an acid catalyst in water at a high temperature of at least 250° C. and a high pressure of at least 15 MPa.