摘要:
5-Formylvaleric esters are prepared by a process which comprises the following steps:(a) Hydroformylation of a pentenoic ester by reaction with carbon monoxide and hydrogen at elevated temperatures and under superatmospheric pressure in the presence of a carbonyl complex of a metal of group 8 of the Periodic Table with formation of a mixture of 5-, 4- and 3-formylvaleric esters,(b) Isolation of the 5-formylvaleric ester from the resulting mixture of 5-, 4- and 3-formylvaleric esters, a mixture essentially consisting of 4- and 3-formylvaleric esters remaining,(c) Cleavage of the mixture essentially consisting of 4- and 3-formylvaleric esters at from 50.degree. to 400.degree. C. in the presence of a catalyst to give pentenoic esters and(d) Recycling of the pentenoic esters to stage (a).
摘要:
5-Methylbutyrolactone is prepared by a process in which a pentenoic ester of the formula IX--CO.sub.2 R (I),where X is CH.sub.2 .dbd.CH--CH.sub.2 --CH.sub.2 --, CH.sub.3 --CH.dbd.CH--CH.sub.2 -- or CH.sub.3 --CH.sub.2 --CH.dbd.CH-- and R is alkyl, cycloalkyl, aralkyl or aryl, or a mixture of these esters is reacted with water at from 50.degree. to 350.degree. C. in the presence or absence of a diluenta) over a zeolite and/or phosphate catalyst orb) in the presence of from 0.01 to 0.25 mole of a sulfonic acid, a Lewis acid and/or a non-oxidizing mineral acid per mole of pentenoic ester or over from 0.1 to 40% by weight, based on the pentenoic ester, of a strongly acidic ion exchanger as a catalyst in a first stage, or the pentenoic ester of the formula I, where X and R have the stated meanings, is hydrolyzed in a first stage with the aid of a strongly acidic ion exchanger as a catalyst to give the pentenoic acid of the formula I, where R is hydrogen, and the resulting pentenoic acid is subjected to cyclization in a second stage in the presence of from 0.005 to 0.1 mole of a sulfonic acid, a Lewis acid or a non-oxidizing mineral acid per mole of pentenoic acid or over from 0.1 to 20% by weight, based on the pentenoic acid, of a strongly acidic ion exchanger at from 50.degree. to 350.degree. C.
摘要:
Caprolactam is prepared by a process in which(a) a 5-formylvalerate is reacted with excess ammonia and hydrogen in the presence of an alkanol as a solvent and in the presence of a hydrogenation catalyst under superatmospheric pressure in the liquid phase at from 40.degree. to 130.degree. C.,(b) excess ammonia and hydrogen are separated off from the reaction mixture and(c) the reaction mixture thus obtained is heated to 150.degree.-250.degree. C. and .epsilon.-caprolactam is obtained.
摘要:
In an improved process for the preparation of 6-aminocaproates by reacting a 5-formylvalerate with ammonia and hydrogen using an alkanol as a solvent in the presence of a hydrogenation catalyst at elevated temperatures and under superatmospheric pressure, the improvement comprises carrying out the reaction at from 40.degree. to 95.degree. C.
摘要:
Cyclic ketones of the formula ##STR1## where n is an integer from 4 to 6, are prepared by converting an aliphatic dicarboxylate of the formulaR.sup.1 OCC--(CH.sub.2).sub.n --COOR.sup.2 IIwhere n has the above meaning, R.sup.1 and R.sup.2 are each alkyl, cycloalkyl, aralkyl or aryl and R.sup.2 may furthermore be hydrogen, at from 150.degree. to 450.degree. C. over a solid oxide catalyst.
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:
Methyl 4-pentenoate is isolated from mixtures containing this and methyl 3-pentenoate by a process in which from 0.25 to 0.4 part by weight of water is added per part by weight of methyl 4-pentenoate, and the azeotrope of methyl 4-pentenoate and water is distilled off.
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.
摘要:
A process for the manufacture of pent-3-enoic acid and its alkyl esters, of the general formulaCH.sub.3 --CH.dbd.CH--CH.sub.2 --CO--ORwhere R is hydrogen or alkyl of 1 to 4 carbon atoms, comprising carbonylating butadiene with carbon monoxide and a compound ROH at from 300 to 1,000 bars CO pressure and from 100.degree. to 160.degree. C. in the presence of cobalt catalysts and nitrogen bases, wherein C.sub.4 cuts are used as starting materials and a tertiary amine having a pK.sub.A of from 3 to 11 is used as the nitrogen base. The pent-3-enoic acid or alkyl esters produced may be used for the manufacture of adipic acid or its alkyl esters, which compounds are starting materials for the manufacture of nylons.
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).