GB719919A - Improvements in the production of aliphatic oxygen compounds - Google Patents

Abstract

Aliphatic oxygen compounds are obtained by the action of carbon monoxide on saturated aliphatic alcohols containing up to 4 carbon atoms, or their ethers with saturated alcohols, at elevated temperatures and under super-atmospheric pressure in the presence of a complex compound of a cobalt halide of general formula Q2CoX4 in which Q is an organic quaternary ammonium or phosphonium radical and in which X stands for a chlorine, bromine or iodine ion, at least two of which are bromine or iodine ions. Suitable catalysts are, for example, [(C2H5)3(C4H9)N]2CoBr4, [(C2H5)2(C4H9)2N]2 CoI4, [(C3H7)4N]2CoBr2I2 [(CH3)3(C6H4)N]2CoBr4, [(C5H5N)(C4H9)]2CoBr4, [(C5H5N)(C6H5CH2)]2CoI4 and the corresponding phosphonium compounds. In particular, the triaryl alkyl phosphonium cobalt bromides, in which the alkyl group contains from 1 to 6 carbon atoms and the aryl group is phenyl or a homologue thereof, are suitable. The catalysts may be formed in situ, for example, by adding to the starting material a cobalt halide and an organic quaternary ammonium or phosphonium halide. Preferably the reaction is carried out between 70 DEG and 250 DEG C. and at pressures above 50 atmosphere. The carbon monoxide may be pure or mixed with other gases such as nitrogen, methane, carbon dioxide and hydrogen. The reaction may be carried out continuously or otherwise. Preferably a concentration of 0.01 and 1 per cent of cobalt based on starting materials is used. In the examples: (a) methanol is treated with a mixture of carbon monoxide and hydrogen in the presence of di-(butyl-pyridinium) cobalt tetrabromide [(C5H5N(C4H2)]2.CoBr4 to give methyl acetate and acetaldehyde dimethylacetal; (b) methanol is treated with a mixture of carbon monoxide and hydrogen in the presence of dibutyl dipyridinium cobalt tetrabromide, triethyl butyl ammonium cobalt tetrabromide and pyridine to give a mixture of methyl acetate, acetic acid, acetaldehyde dimethyl acetal and a small amount of acetaldehyde; (c) methanol is treated with a mixture of carbon monoxide and hydrogen in the presence of triethyl butyl ammonium cobalt tetrabromide to give methyl acetate, acetic acid and acetaldehyde dimethyl acetal; if pure carbon monoxide is used a mixture of methyl acetate and acetic acid is obtained; (d) methanol is heated with a mixture of carbon monoxide and hydrogen in the presence of triphenyl butyl phosphonium cobalt tetrabromide to give a mixture of acetic acid, methyl acetate and acetaldehyde dimethyl acetal; (e) n-butanol is treated with a mixture of carbon monoxide and hydrogen in the presence of trimethyl butyl ammonium cobalt tetrabromide to give n-butyl valerate and n-valeric acid; (f) butane diol-1,4 is treated with a mixture of carbon monoxide and hydrogen in the presence of triethyl butyl ammonium monoxide and hydrogen in the presence of triethyl butylammonium cobalt tetrabromide to give d -valerolactone, n-valeric acid and adipic acid; similar results are obtained if a mixture of anhydrous cobalt bromide and triphenyl butylphosphonium bromide [(C6H5)3(C4H9)P]Br is used as catalyst; (g) methanol is treated with a mixture of carbon monoxide and hydrogen in the presence of a mixture of cobalt bromide and triphenyl ethyl phosphonium iodide to give acetic acid with some methyl acetate; (h) butane-diol 1.4 is treated with a mixture of carbon monoxide and hydrogen in the presence of triphenyl ethyl phosphonium cobalt diodide dibromide to give a mixture of adipic acid and n-valeric acid; and (j) a solution of dimethyl ether in N-methyl pyrrolidone is treated with a mixture of carbon monoxide and hydrogen in the presence of [(C2N5)4N]2CoBr2I2 to give acetic anhydride; (k) methanol is treated with a mixture of carbon monoxide and hydrogen in the presence of triethyl methyl ammonium cobalt dibromide dichloride to give a mixture of acetic acid and methyl acetate; a similar result is obtained if a mixture of triethyl methyl ammonium chloride and anhydrous cobalt iodide is used as catalyst.