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:
3-pentenoates are prepared by isomerization of 2-pentenoates to 3-pentenoates by a process in which the 2-pentenoate is treated with from 0.01 to 0.5 mole of cyclic tertiary amine having a pK.sub.a of >6 per mold of 2-pentenoate at from 50.degree. to 250.degree. C. and the 3-pentenoate is distilled off continuously.
摘要:
Caprolactam is prepared by a process in which(a) the 5-formylvalerate is reacted with excess ammonia and hydrogen in the presence of an alkanol as the 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,(c) the resulting reaction mixture is reacted with water at elevated temperatures with simultaneous removal of alkanols, and(d) the reaction mixture thus obtained is heated to 150.degree.-370.degree. C. and .epsilon.-caprolactam is obtained.
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:
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:
Caprolactam is prepared by heating a 6-aminocaproic ester at 100.degree.-320.degree. C. in the presence of a reaction medium comprising an aromatic hydrocarbon which is liquid under reaction conditions and has a boiling point from 80.degree. to 240.degree. C., and isolating caprolactam from the reaction medium.
摘要:
.epsilon.-caprolactam is prepared by a process in which(a) a 5-formylvalerate is reacted with water in the presence of an acidic agent at from 30.degree. to 200.degree. C.,(b) the 5-formylvaleric acid thus obtained is reacted with excess ammonia and hydrogen in the presence of a hydrogenation catalyst and of a solvent which is inert under the reaction conditions, at from 50.degree. to 150.degree. C. under superatmospheric pressure, and(c) after the ammonia has been separated off, the resulting solution of 6-aminocaproic acid is heated to 150.degree.-370.degree. C. and the caprolactam formed is isolated.
摘要:
2-Methyl-2-alkenals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl which may additionally carry aromatic radicals, or an aromatic radical, are prepared by isomerizing a 2-alkylacrolein of the formula ##STR2## in the presence of hydrogen and of a catalyst which contains palladium and an oxide or salt of a rare earth metal as active components, at from 20.degree. to 120.degree. C. and under from 1 to 100 bar.
摘要:
A process for the coproduction of 6-aminocapronitrile and hexamethylenediamine starting from adiponitrile by a) hydrogenating adiponitrile in the presence of a catalyst comprising an element of the eighth transition group as catalytically active component, to obtain a mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, b) distillatively removing hexamethylenediamine from the mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, and either cl) distillatively removing 6-aminocapronitrile, and then d1) distillatively removing adiponitrile, or c2) simultaneously distillatively removing 6-aminocapronitrile and adiponitrile into separate fractions is characterized by base of column temperatures below 185° C. in steps d1) or c2).