摘要:
Adipic acid is 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 cobalt carbonyl or rhodium carbonyl complex 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) dehydrocarbonylation of the mixture consisting essentially of 4- and 3-formylvaleric esters in the presence of one or more elements of subgroup 8 of the Periodic Table at from 50.degree. to 400.degree. C. with formation of pentenoic esters, and recycling of the latter to stage (a) for hydroformylation,(d) oxidation of the 5-formylvaleric ester from stage (b) with molecular oxygen or a gas containing molecular oxygen to give a monoester of adipic acid, and(e) hydrolysis of the monoester of adipic acid to give adipic acid.
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 heating a 6-aminocaproic ester in liquid phase in the presence of water to 230.degree.-350.degree. C. under superatmospheric pressure in a reaction medium comprising a liquid aromatic hydrocarbon having a boiling point of from 80.degree. to 240.degree. C. which is inert under reaction conditions, and isolating caprolactam from the reaction mixture.
摘要:
6-Aminocaproic acid is prepared by(a) reacting a 5-formylvaleric acid ester with water in the presence of an acid agent at 30.degree.-200.degree. C. and(b) reacting the 5-formylvaleric acid thus obtained with excess ammonia and hydrogen in the presence of a hydrogenation catalyst and of a solvent which is inert under the reaction conditions at 50.degree.-150.degree. C. under superatmospheric pressure.
摘要:
2-Substituted 4-acyloxy-2-butenals of the general formula I ##STR1## where R.sup.1 is alkyl of 1 to 12 carbon atoms which may be substituted by cycloalphatic, aromatic or heterocyclic radicals, by alkenyl or alkynyl or by hydroxyl, ether, thioether, acetoxy acyl, alkylamino, carboxyl or carbalkoxy, and R.sup.2 is acyloxy, are prepared by reacting a monosubstituted acetaldehyde of the general formula II ##STR2## where R.sup.2 has the abovementioned meaning, with an aldehyde of the general formula III ##STR3## where R.sup.1 has the abovementioned meaning, in the presence of a linear or cyclic secondary amine and of an organic acid at from 20.degree. to 100.degree. C.
摘要:
A process for the preparation of 4-acetals of butene-1,4-dial of the formula ##STR1## where R is an alkyl, alkenyl, cycloalkyl or aralkyl radical of 1 to 12 carbon atoms which may contain alkoxy groups, or the two radicals R together form an alkylene or alkenylene radical of 2 to 10 carbon atoms which may contain alkoxy groups, and R.sup.1 is an alkyl, alkenyl or alkynyl radical of 1 to 12 carbon atoms which may be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxyl, ether, thioether, acyl, alkylamino, carboxyl or carbalkoxy groups, or is an unsubstituted or substituted aryl radical or an alkoxy, alkylthio or acyloxy group, wherein a glyoxal monoacetal of the formula ##STR2## is reacted with an aldehyde of the formulaR.sup.1 --CH.sub.2 --CHO IIIat up to 150.degree. C., and novel acetals of butene-1,4-dial.
摘要:
6-Aminocaproic esters are prepared by reacting alkyl 5-formylvalerates with excess ammonia and hydrogen in the presence of ruthenium catalysts at elevated temperature under superatmospheric pressure in liquid ammonia as reaction medium.
摘要:
Polyoxyalkylene glycols are prepared by a process in which tetrahydrofuran is polymerized with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals in the absence of water and in the presence of a monohydric alcohol or of a monocarboxylic acid with the aid of an anhydrous heteropoly acid catalyst, and the polyoxyalkylene glycol is liberated from the resulting polyoxyalkylene glycol monoethers or polyoxyalkylene glycol monoesters by cleavage of the monoether or monoester bond.
摘要:
3-Pentenoates are prepared by isomerization of 2-pentenoates to 3-pentenoates by a process in which the 2-pentenoate is treaated with from 0.01 to 0.5 mole of cyclic tertiary amine having a pK.sub.a of >6 per mole of 2-pentenoate at from 50.degree. to 250.degree. C. and the 3-pentenoate is distilled off continuously.