Preparing an alpha, beta unsaturated ketones by condensing aldehydes with ketones via a multiphase reaction in a tubular reactor

摘要

A process for preparing a,b-unsaturated ketones of formula R2-CH=C(R3)-C(=O)-R1 comprises reacting an aldehyde -R2-C(=O)H with a ketone -R3-CH2-C(=O)-R1. The catalyst is present in continuous phase and at lest only one reactant is present in dispersed phase and the loading factor of the tubular rector is not less than 0.8 wherein: R1 and R2 are independently an optionally saturated aliphatic, cycloaliphatic or cycloaliphatic-aliphatic hydrocarbon, which may contain alkyl substituents and/or endo-alkylene groups or can be an aromatic hydrocarbon; R3 is H, or an aliphatic hydrocarbon or together with R1 and the adjacent carbons form an alicyclic ring and in R1 to R3 one or more methylene groups which are not a disposed relative to the carbonyl groups may be substituted with a oxygen or sulphur atom.