摘要:
A process for the preparation of polyoxyalkylene glycols or polyoxyalkylene glycol copolymers from polyoxyalkylene glycol formates or the formates of polyoxyalkylene glycol copolymers comprises reacting the formates of polyoxyalkylene glycols or of polyoxyalkylene glycol copolymers in the liquid phase in the presence of a heterogeneous catalyst which contains, as catalytically active component, rhenium and/or at least one element from sub-group VIII of the Periodic Table of the Elements.
摘要:
Polyoxyalkylene glycol monoesters of carboxylic acids are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran 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 is polymerized in the absence of water and in the presence of a carboxylic acid and of an anhydrous heteropolyacid catalyst.
摘要:
2-Methyl-1,4-butanediol and 3-methyltetrahydrofuran are prepared by reacting a compound of the general formula I or II ##STR1## where R.sup.1 and R.sup.2 are each hydrogen or C.sub.1 -C.sub.8 -alkyl and the formyl group of II may also be present as acetal with a C.sub.1 -C.sub.8 -alkanol, is reacted with hydrogen in the presence of copper or of a metal of groups 7 to 10 of the Periodical Table of elements or of a compound of these metals.
摘要:
Polyoxyalkylene glycol monoethers of monohydric alcohols are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran 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 is polymerised in the absence of water and in the presence of a monohydric alcohol and of an anhydrous heteropoly acid catalyst.
摘要:
Mixtures which contain 1,4-butanediol and tetrahydrofuran are prepared by heating 4-hydroxybutyraldehyde of the formula ##STR1## at 20.degree.-300.degree. C. in the presence or absence of 1,4-butanediol and subjecting the resulting acetals of the formulae ##STR2## to a catalytic hydrogenation at 50.degree.-300.degree. C. and 1-350 bar.
摘要:
The preparation of N-substituted 2-pyrrolidones (I) by the reaction of maleic acid, fumaric acid, or succinic acid or functional derivatives of these acids (compounds II) with a primary amine (III) or by the reaction of amides or imides derived from II and III under hydrogenating conditions in a synthesis stage followed by isolation, by distillation, of I and other volatile components from the resulting reaction mixture, in which the residues present following distillation are subjected to further hydrogenation treatment and the compound (I) thus formed is isolated by distillation.
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:
A process for the preparation of propane-1,2,3-tricarboxylic acid, tetrahydrofurfurylacetic acid and the C.sub.1 - to C.sub.20 -alkyl or C.sub.7 - to C.sub.12 -aralkyl esters thereof, propane-1,2,3-trimethanol, 3-methyltetrahydrofuran, 3-(2'-hydroxyethyl)tetrahydrofuran, 4-hydroxymethyltetrahydropyran, 2-methyl-.gamma.-butyrolactone and/or 3-methyl-.gamma.-butyrolactone, comprises reacting citric acid or the C.sub.1 - to C.sub.20 -alkyl or C.sub.7 - to C.sub.12 -aralkyl esters thereof on hydrogenation catalysts in non-aqueous solvents at from 50.degree. to 400.degree. C. and at from 1 to 400 bar.
摘要:
A process for preparing 4-hydroxymethyltetrahydropyran comprises reacting tetrahydrofurans of the general formula I ##STR1## where R.sup.1 is hydrogen, C.sub.1 - to C.sub.6 -alkyl or --CO--R.sup.2, andR.sup.2 is hydrogen or C.sub.1 - to C.sub.6 -alkyl,at from 0.degree. to 400.degree. C. and from 0.001 to 400 bar in the presence of acidic catalysts.
摘要:
Abstract of the Disclosure: Products of the reduction of 4-hydroxybutyric acid derivatives of the formula IIa ##STR1## where one of A and B is methylene and the other is cyclopropylidene, or of C.sub.1 --C.sub.4 --alkyl esters (IIb) or lactones (IIc) of these acids IIa, are prepared by hydrogenating the compounds IIa or IIb or IIc catalytically using hydrogen in the presence of a heterogeneous hydrogenation catalyst, giving novel compounds which can be used to prepare polymers.