GB581627A - Improvements in or relating to the production of vinyl and ethylidene esters - Google Patents

Abstract

Vinyl and ethylidene esters are produced by reacting acetylene with a saturated aliphatic monocarboxylic acid in the presence of a small amount of a compound of the formula <FORM:0581627/IV/1> where X is nitrogen, phosphorus or arsenic, R is an aromatic radical, and R1 and R11 are the same or different alkyl radicals. Compounds specified are dimethyl, diethyl, dipropyl, and methyl ethyl anilines, dimethyl naphthylamine, dimethyl phenyl and diethyl phenyl phosphine and arsine, methyl ethyl phenyl arsine, p-chlordimethyl aniline, p-dimethyl aminoacetophenone, o-dimethyl-aminobenzoic acid, diethyl-o-toluidine, diethyl-a -naphthylamine, p-bromphenyl dimethyl arsine, dimethyl sulphanilic acid, and tetramethyl diaminodiphenyl methane. The proposed concentration is about .001-.01 gram mol/1. of absorber liquor. About .005-.1 gram mol/1. of methane trisulphonic may also be present. Acetylene may be passed in excess into the acid containing a mercury catalyst such as mercuric sulphate or acetate at 80-100 DEG C., the vaporized ester being recovered by condensation. Carboxylic acids specified are acetic, propionic, and butyric. The acetylene may be recycled. Increased yields, and ratios of vinyl esters in the products are obtained. In examples: (1) glacial acetic acid containing acetic anhydride, mercury sulphate, dimethyl aniline (.004 gram mol/1.), and methane trisulphonic acid trihydrate (.007 gram mol/1.) is heated to about 85 DEG C. while flushing with acetylene, and then held at 90-95 DEG C. while passing acetylene; (2) mercuric acetate is the catalyst and is added as a solution in acetic acid at intervals during the absorption of the acetylene; (3) and (4) reaction is effected as in (1) or (2) using .002 gram mol/1. dimethyl aniline; (5) the dimethyl aniline is dissolved in the catalyst solution of (2) and added at intervals.