Submitted by: Submitted by Tulin
Views: 32
Words: 4039
Pages: 17
Category: Science and Technology
Date Submitted: 03/05/2015 01:31 PM
Continuous process for the preparation of pivaloyl chloride and of aroyl chloride
US 6605743 B1
ABSTRACT
The invention relates to a continuous process for the preparation of pivaloyl chloride and of aroyl chloride, in particular of benzoyl chloride, which consists in reacting pivalic acid with a trichloromethylated aromatic compound in the presence of a catalyst at a temperature of between 60° C. and 180° C. under reduced pressure. The products formed are continuously removed from the reaction region, the hydrogen chloride formed being treated in a washing region in which a trichloromethylated compound moves countercurrentwise.
IMAGES(6)
CLAIMS(18)
What is claimed is:
1. A continuous process for the preparation of pivaloyl chloride and of aroyl chloride (2) by reaction of pivalic-acid with a trichloromethylated aromatic compound (1) according to the reaction:
in which R represents a halogen atom, a linear or branched alkyl radical having a carbon number of 1 to 4, a linear or branched perfluoroalkyl radical having a carbon number of 1 to 4 or a —COCl radical, m=0, 1 or 2 and n=1, 2 or 3 and in which the —CCl3 groups are situated on non-adjacent carbon atoms when n>1, in the presence of at least one Friedel-Crafts catalyst, said process comprising
simultaneously and continuously introducing pivalic acid, at least one trichloromethylated aromatic compound (1) and at least one Friedel-Crafts catalyst into a reactor and reacting with stirring and under reduced pressure at a temperature of 60° C. to 180° C.,
continuously separating unconverted reactants from products formed in gas flow exiting at the top of the reaction region,
partially condensing the products formed into a liquid mixture comprising pivaloyl chloride and aroyl chloride (2),
treating, in a washing region in which a trichloromethylated aromatic compound (1) moves countercurrentwise, remaining uncondensed gaseous mixture comprising hydrogen chloride, and...