摘要:
4-Pentenoates are prepared by isomerization of isomeric pentenoates in the presence of a catalyst, by a process in which isomeric pentenoates are treated at elevated temperatures with an acidic ion exchanger or acidic zeolite which contains a noble metal of group eight of the periodic table, and the 4-pentenoate is distilled off from the reaction mixture.
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:
C.sub.1 -C.sub.4 -alkyl pentenoates are obtained from reaction mixtures which contain this and which are obtained by reacting butadiene, or a butadiene-containing hydrocarbon mixture, with carbon monoxide and a C.sub.1 -C.sub.4 -alkanol, in the presence of a cobalt carbonyl catalyst and a tertiary nitrogen base at elevated temperatures and under superatmospheric pressure by a process in which(a) the liquid reaction mixture freed from excess carbon monoxide is treated with hydrogen at elevated temperatures and under from 5 to 80 bar,(b) hydrocarbons are distilled off from the resulting liquid reaction mixture,(c) the C.sub.1 -C.sub.4 -alkyl pentenoate, the alkanol and the nitrogen base are then distilled off under reduced pressure, and(d) the C.sub.1 -C.sub.4 -alkyl pentenoate is obtained by fractional distillation from the distillate containing this compound, the alkanol and the tertiary nitrogen base.
摘要:
Pure monoesters of adipic acid are prepared by a process in which(a) a pentenoate is reacted with carbon monoxide and hydrogen at from 90.degree. to 140.degree. C. and under from 5 to 300 bar in the presence of a carbonyl complex of cobalt or of rhodium, and a 5-formylvalerate is separated off, and(b) the 5-formylvalerate thus obtained is oxidized with molecular oxygen, or with a gas containing this, at from 20.degree. to 100.degree. C. under from 1 to 10 bar.
摘要:
An improved process for the preparation of alkyl formylvalerates, wherein butadiene or a butadiene-containing hydrocarbon mixture is reacted, in a first stage, with carbon monoxide and alkanols in the presence of cobalt carbonyl complexes and, per mole of butadiene, from 0.5 to 2 moles of tertiary nitrogen bases having a pK.sub.a of from 3 to 11, at from 80.degree. to 150.degree. C. and from 300 to 2,000 bar, and, in a second stage, the resulting alkyl pentenoate is reacted with carbon monoxide and hydrogen in the presence of cobalt carbonyl complexes at from 100.degree. to 160.degree. C. and from 100 to 300 bar, the improvement being that tertiary nitrogen bases, excess alkanols and any unconverted hydrocarbons are distilled off from the reaction mixture obtained in the first stage, with the proviso that the reaction mixture is treated, before or during the distillation, with gases containing molecular oxygen, and the residual reaction mixture containing alkyl pentenoate and cobalt catalyst is used in the second stage.
摘要:
The isolation and regeneration of catalysts of type I or IIclRh(CO)(PR.sub.3).sub.2 Ihrh(CO)(PR.sub.3).sub.3 II,where the R's are identical or different hydrocarbon radicals, to give the catalysts in a pure form, is effected by regenerating aqueous rhodium salt solutions, as obtained on treating distillation residues of hydroformylation mixtures with oxygen-containing mineral acids and peroxides, by a method wherein the said aqueous rhodium salt solutions are treated with a cation exchanger, the latter is then separated from the solution, the absorbed rhodium ions are desorbed with hydrochloric acid, the hexachlororhodate solutions, containing hydrochloric acid, are reacted, in the presence of a water-soluble organic solvent and a tertiary phosphine PR.sub.3, with carbon monoxide, or with compounds which eliminate carbon monoxide, at from 0.degree. to 150.degree. C and from 1 to 5 bars, and the resulting complexes I or, if the process is carried out under hydrogenating conditions, the resulting complexes II, are separated off.
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:
A process for the manufacture of salts of alkanedicarboxylic acids of 4 to 12 carbon atoms and alkanediamines of 3 to 14 carbon atoms, comprising reacting esters of alkanols of 1 to 4 carbon atoms and alkanedicarboxylic acids of 4 to 12 carbon atoms with alkanediamines of 3 to 14 carbon atoms in stoichiometric amounts in the presence of water at an elevated temperature, with continuous removal of the alkanols formed, in which process the reaction is carried out, from the start, in the presence of the particular salt of alkanedicarboxylic acid and alkanediamine which is to be manufactured.