摘要:
A process for the preparation of butanedicarboxylic acid esters, wherein(a) an aqueous cobalt salt solution is treated with excess carbon monoxide and hydrogen in the presence of active charcoal laden with cobalt carbonyl,(b) the resulting aqueous solution of cobalt carbonyl hydride is extracted with butadiene or a butadiene containing hydrocarbon mixture and the aqueous phase is separated off,(c) the butadiene, or butadiene/hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl, is reacted with carbon monoxide and excess C.sub.1 -C.sub.4 -alkanol in the presence of a tertiary nitrogen base,(d) the resulting reaction mixture is freed from the tertiary nitrogen base contained therein, down to a content of from 0.1 to 0.3 mole per mole of pentenoic acid ester, and from excess hydrocarbons, and the pentenoic acid ester remaining in the reaction mixture is reacted with carbon monoxide and excess C.sub.1 -C.sub.4 -alkanol in the presence of the cobalt carbonyl and tertiary nitrogen base contained in the reaction mixture,(e) the reaction mixture is treated with an oxidizing agent in the presence of the aqueous acid solution which has been separated off in stage (b), and the mixture is separated into an organic phase, from which butanedicarboxylic acid esters are isolated by distillation, and an aqueous phase, and(f) the aqueous phase is extracted with water-immiscible solvents, the phases are separated, and the resulting aqueous phase is freed from alkanols and tertiary nitrogen base and is recycled to stage (a).
摘要:
Carboxylates which contain aldehydes, acetals and/or unsaturated compounds and are obtained by reacting an olefinically unsaturated compound with carbon monoxide and an alkanol are purified by a process wherein the said carboxylates are treated with hydrogen at elevated temperatures in the presence of an acidic ion exchanger or zeolite doped with one or more metals of group VIII of the periodic table, and the resulting low and/or high boilers are separated off by distillation.
摘要:
A process for the preparation of C.sub.1 -C.sub.4 -alkyl pent-3-enoates, wherein butadiene, or a hydrocarbon mixture containing butadiene, either of which contains not more than 0.1% by weight of butynes, is reacted with carbon monoxide and an alkanol of 1 to 4 carbon atoms in the presence of a cobalt carbonyl catalyst and a tertiary nitrogen base, having a pK.sub.A of 3-11, at from 100.degree. to 140.degree. C. under a pressure of from 300 to 1,000 bar.
摘要:
.delta.-Formylvalerates are prepared by a process wherein a 3-pentenoate is treated with an isomerization catalyst at elevated temperatures and a 4-pentenoate is distilled off, and the resulting 4-pentenoate is reacted with carbon monoxide and hydrogen at from 80 to 160.degree. C. under from 1 to 30 bar in the presence of a rhodium carbonyl complex which has been modified with tertiary organic phosphines or phosphites.
摘要:
Ethanol is produced continuously via the carbonylation of methanol, by(a) carbonylating methanol, in a reactor R, in the presence of a carbonyl complex of a metal of group VIII of the periodic table and of a halogen compound,(b) separating, in a distillation column D1, the reactor discharge, into a top fraction comprising methyl acetate, methanol, dimethyl ether and an organohalogen compound, and into a bottom fraction comprising water, small quantities of acetic acid and the catalyst, if the latter is not in a fixed bed, the residence time being so adjusted that the greater part of the acetic acid reacts with the methanol present to give methyl acetate,(c) separating the top fraction from D1, in a distillation column D2, into a top fraction comprising small quantities of methyl acetate, methanol, dimethyl ether and the organo-halogen compound, and a bottom fraction comprising methyl acetate and methanol, and recycling the top fraction to reactor R,(d) distilling off, via the top of distillation column D3, the greater part of the water from the bottom fraction from D1and removing this water from circulation, and recycling to reactor R the bottom fraction consisting of small quantities of water, acetic acid and the catalyst,(e) using hydrogen to hydrogenate, in the hydrogenation reactor H, the bottom fraction from D2, in a conventional manner, to give a mixture of methanol and ethanol, and(f) separating the mixture into ethanol and methanol in a distillation column D4, and recycling the methanol to reactor R.
摘要:
A process for purifying carboxylic acid esters which have been obtained by reacting olefinically unsaturated compounds with carbon monoxide and alkanols and which contain aldehydes or acetals, wherein the said esters are treated with a strongly acidic agent, with or without addition of water.
摘要:
In a process for the preparation of butanedicarboxylic acid esters by(a) reacting butadiene or hydrocarbon mixtures containing butadiene with carbon monoxide and a C.sub.1 -C.sub.4 -alkanol in the presence of a tertiary nitrogen base and a cobalt carbonyl catalyst at from 80.degree. to 150.degree. C. under superatmospheric pressure,(b) removing the greater part of the tertiary nitrogen base together with any excess hydrocarbon and(c) reacting the resulting pentenoic acid ester, in the presence of the catalyst remaining in the reaction mixture, and in the presence of the remaining amount of tertiary nitrogen base, with carbon monoxide and a C.sub.1 - to C.sub.4 -alkanol at from 140.degree. to 200.degree. C. under superatmospheric pressure, to give the butanedicarboxylic acid ester, the improvement wherein the reaction mixture in stage c) is substantially free from dissolved butadiene or butadiene bonded to the catalyst.Butanedicarboxylic acid esters may be used for the preparation of polymers.
摘要:
In a process for the preparation of dimethyl butanedicarboxylates, wherein(a) butadiene or a hydrocarbon mixture containing butadiene is reacted with carbon monoxide and methanol in the presence of a tertiary nitrogen base and a cobalt carbonyl catalyst at from 80.degree. to 150.degree. C. under superatmospheric pressure,(b) the greater part of the tertiary nitrogen base and any excess hydrocarbons are removed and(c) the methyl pentenoate thus obtained is reacted with carbon monoxide and methanol, in the presence of a cobalt carbonyl catalyst and the residual amount of tertiary nitrogen base, at from 140.degree. to 200.degree. C. under superatmospheric pressure, to give the dimethyl butanedicarboxylate, the improvement that the reaction mixture obtained in stage (a) after reaction of the butadiene is cooled until it separates into two phases, and a part-stream of from 20 to 80% by volume of the lower phase is recycled to stage (a).
摘要:
A process for the manufacture of butanedicarboxylic acid esters, wherein(a) an aqueous cobalt salt solution is treated, at from 50.degree. to 200.degree. C. and under a pressure of from 50 to 500 bars, with excess carbon monoxide and hydrogen in the presence of active charcoal laden with cobalt carbonyl,(b) the resulting aqueous solution of cobalt carbonyl hydride is extracted with butadiene or with a hydrocarbon mixture containing butadiene and the aqueous phase is separated off,(c) the butadiene, or butadiene-hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl is reacted with carbon monoxide and an excess of an alkanol of 1 to 4 carbon atoms in the presence of from 0.5 to 2 moles, per mole of butadiene, of a tertiary nitrogen base having a pK.sub.a of from 3 to 11, at from 80.degree. to 150.degree. C. under a pressure of from 300 to 2,000 bars, and(d) the resulting reaction mixture is freed from the tertiary nitrogen base contained therein, except for from 0.1 to 0.3 mole per mole of pentenoic acid ester, and from excess hydrocarbons, the pentenoic acid ester remaining in the reaction mixture is reacted with carbon monoxide and an excess of an alkanol of 1 to 4 carbon atoms at from 140.degree. to 200.degree. C. and under pressures of from 100 to 400 bars in the presence of the amounts of cobalt carbonyl and tertiary nitrogen base contained in the reaction mixture, and excess alkanol and free nitrogen base are then distilled off, and(e) the reaction mixture which remains, and which contains cobalt catalyst, the butanedicarboxylic acid ester and by-products is treated with an oxidizing agent in an aqueous acid medium and the mixture is separated into an organic phase, from which the butanedicarboxylic acid ester is isolated by distillation, and into an aqueous phase containing cobalt salts.Butanedicarboxylic acid esters may be used for the manufacture of adipic acid and of nylons.
摘要:
A process for the manufacture of butanedicarboxylic acid esters, wherein(a) an aqueous cobalt salt solution is treated with carbon monoxide and hydrogen in the presence of active charcoal,(b) the resulting aqueous solution is extracted with butadiene or with a hydrocarbon mixture containing butadiene,(c) the butadiene, or butadiene/hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl, is reacted with carbon monoxide and an excess of an alkanol of 1 to 4 carbon atoms in the presence of a tertiary nitrogen base,(d) the tertiary nitrogen bases contained in the resulting reaction mixture are removed from the latter to the extent of leaving from 0.1 to 0.3 mole per mole of pentenoic acid ester, excess hydrocarbons are also removed, the pentenoic acid ester remaining in the reaction mixture is reacted with carbon monoxide and an alkanol of 1 to 4 carbon atoms, and thereafter excess alkanol and free nitrogen base are distilled off and(e) the residual reaction mixture, containing cobalt catalysts, butanedicarboxylic acids and by-products is treated with an oxidizing agent in an aqueous acid medium and the mixture is separated into an organic phase, from which butanedicarboxylic acid esters are isolated by distillation, and an aqueous phase containing cobalt salts, which phase is extracted with a water-immiscible solvent.