Patent ID: 7141698
Filing Date: 2006-11-28
Classification: C07C

Abstract:
1. A continuous process for preparing pseudoionones of the general formulae I or I′ and isomers thereof where R R R by reacting an aldehyde of the formula (II) with an excess of a ketone of the general formula (III) where R mixing the homogeneous solution of aldehyde, ketone and aqueous alkali metal hydroxide at a temperature of from 10 to 120° C., then removing the water and alkali metal hydroxide which have not dissolved in the reaction mixture, subsequently passing the homogeneous reaction mixture, avoiding backmixing, at a temperature which is from 10 to 120° C. above the boiling point of the lowest-boiling component and a vapor pressure p of from 10 cooling the reaction mixture under decompression, removing the ketone from the reaction mixture with steam in countercurrent and drying the crude product and freeing it of excess aldehyde and secondary components using a rectification column.