Process for the preparation of 3,4-methylenedioxypropiophenone

Abstract

The invention relates to a process for the preparation of 1-(1,3-benzodioxol-5-yl)-1-propanone comprising the step of reacting 3,4-methylendioxybenzene with propionic anhydride in the presence of a bulk or supported catalyst, being said catalyst selected from the group of a sulphonated cross-linked divinylbenzene resin, a sulphonated cross-linked divinylbenzene resin partially exchanged with iron, zinc or gallium, a perfluorinated sulphonic resin, and a perfluorinated sulphonic resin partially exchanged with iron, zinc or gallium, wherein said catalyst has an average particle size from 1 μm to 300 μm, preferably from 1 μm to 180 μm, more preferably from 1 μm to 100 μm as measured with DLS (Dynamic light scattering) or a granulometer. The process is advantageously carried out at stoichiometric ratio between the reagents and with a continuous process.

Dependencies are inferred from the claim text.