CONTINUOUS PRODUCTION OF 3,5,5TRIMETHYLCYCLOHEXA-3-EN-1- ONE(β-ISOPHORONE)

摘要

PURPOSE: Provided is a method for producing β-isophorone by trimerizing acetone in an alkali medium to give α-isophorone and isomerizing α-isophorone by a homogeneous catalyst. CONSTITUTION: (a) α-Isophorone and a solution of alkali hydroxide are continuously introduced into a reaction zone, (b) the reaction mixture is refluxed at 150 deg.C or less under pressure P1 equal to or lower than atmospheric pressure, (c) (1) β-isophorone in a vapor phase is continuously and simultaneously removed from the reaction mixture by distillation under pressure P2 equal to or lower than P1 at 150 deg.C or less and (2) a heavy product is continuously and simultaneously extracted from the reaction mixture so that the content of the heavy product in the reaction mixture is 7 wt.% or less to carry out the removals of (1) and (2) and (e) the condensate of the distillation is continuously sent to the reaction zone.