Abstract: The present invention relates to a process for preparing hydroxyl-containing polymers, in particular for preparing polytetrahydrofuran with terminal hydroxyl groups, from the corresponding acyloxy-containing polymers by transesterification with alcohols in the presence of an alkali metal- or alkaline earth metal-containing catalyst, which entails the appropriate acyloxy-containing polymer being introduced together with the alcohol and the catalyst into a first prereactor (I) and converted therein at least partly to the hydroxyl-containing polymer, and the reaction solution being fed into the upper zone (IIa) of a distillation column (II) into whose lower zone (IIb) alcohol in vapor phase is additionally fed. This involves a phase exchange at the coherent and the disperse phase at the transition from the prereactor to the distillation column. Preferably, in addition to the first prereactor, a further 3 prereactors are used which serve as holdup reactors.

Abstract: The invention relates to a process for preparing hydroxyl-containing polymers, in particular for preparing polytetrahydrofuran with terminal hydroxyl groups, from the corresponding acyloxy-containing polymers by transesterification with alcohols in the presence of a sodium-containing catalyst. In this process the polytetrahydrofuiran solution is passed in the presence of a catalytic amount of water directly through at least one ion exchanger following the transesterification in order to remove the sodium cations.The novel process makes it possible to remove the sodium cations from the sodium-containing catalyst in an economic manner and with little complexity. The residual sodium content can be reduced to values of less than 0.5 ppm.

Abstract: A process for preparing hydroxyl-containing polymers and, in particular, a process for preparing polytetrahydrofuran with terminal hydroxyl groups from the corresponding acyloxy-containing polymers by transesterification with alcohols is carried out continuously in at least one stirred vessel, with the foam produced in the transesterification being fed tangentially to a cylindrical container, preferably a cyclone separator, at an adequate velocity to destroy the foam. The liquid phase which separates out is recycled through a line to the at least one stirred vessel.This continuous process is preferably carried out in a cascade of stirred vessels, in which each stirred vessel or a subunit of at least two stirred vessels can in each case be coupled to a cylindrical container, preferably in the form of a cyclone separator.

Abstract: Acyl chlorides are prepared by reacting a carboxylic acid or its anhydride with carbonyl chloride in the presence of a carboxamide of the formula I ##STR1## where R.sup.1 is a radical of the formula ##STR2## R.sup.2 and R.sup.3 are each alkyl of 1 to 9 carbon atoms, R.sup.4 and R.sup.5 are each hydrogen or alkyl of 1 to 9 carbon atoms and the two radicals R.sup.1 and R.sup.2 may furthermore be a hydrocarbon radical which completes the moiety ##STR3## to form a heterocyclic structure, and the stated alkyl and hydrocarbon radicals may furthermore contain substituents which are inert under the reaction conditions.

Abstract: Polytetrahydrofuran or C.sub.2 -C.sub.10 -alkylene oxide/tetrahydrofuran copolymers having a molecular weight of from 250 to 20,000 Dalton are prepared by the cationic polymerization of tetrahydrofuran or tetrahydrofuran and C.sub.2 -C.sub.10 -alkylene oxides in the prsence of a promoter by a process in which the catalyst used is a mixture of one or more C.sub.2 -C.sub.6 -di- or tricarboxylic acids with boric acid.

Abstract: To remove phosgene from off-gases, the former is reacted in a washing zone with a liquid which contains or is composed of compounds of the formula ##STR1## where R.sub.1 and R.sub.2 are identical or different and are each aliphatic or cycloaliphatic alkyl of 1 to 8 carbons, or R.sub.1 and R.sub.2 are --(CH.sub.2).sub.n -- where n is 4 or 5, R.sub.3 is hydrogen or aliphatic or cycloaliphatic alkyl of 1 to 6 carbon atoms, or R.sub.1 or R.sub.2 and R.sub.3 are --(CH.sub.2).sub.m -- where m is 3, 4 or 5.The liquid can be regenerated by the addition of water, and the regenerated liquid can be returned to the washing zone.

Abstract: A process for the preparation of a carboxylic chloride of the general formula I ##STR1## in which R denotes C.sub.1 -C.sub.30 -alkyl, C.sub.2 -C.sub.30 -alkenyl or C.sub.2 -C.sub.30 -alkynyl, from a carboxylic acid of the general formula II ##STR2## in which R has the meanings stated, and phosgene COCl.sub.2 (III), in the presence of a catalyst adduct comprising phosgene and N,N-disubstituted formamide of the general formula IV ##STR3## in which R.sup.1 and R.sup.2 are independently C.sub.1 -C.sub.3 -alkyl or R.sup.1 and R.sup.2 together form a C.sub.4 - or C.sub.5 -alkylene chain which may or may not be interrupted by an oxygen atom or by a nitrogen atom carrying a C.sub.1 -C.sub.3 -alkyl group or CHO, the product being isolated by phase separation, wherein the amount of phosgene added to the formamide (IV) is from 20 to 70% molar, based on the formamide.

Abstract: The preparation of an alkyl, alkenyl, or alkynyl chloride by the reaction of a corresponding alcohol with phosgene or thionyl chloride in the presence of a phosphine oxide acting as catalyst, wherein the catalyst used is an aliphatic, cycloaliphatic, or cyclic/aliphatic phosphine oxide.

Abstract: The invention relates to a process for the preparation of cyclopentanone from adipic acid wherein adipic acid vapor in an inert gas at a temperature of from 250.degree. C. to 450.degree. C., possibly accompanied by water vapor, is passed over an oxygenous acidic or basic catalyst.

Abstract: Aromatic nitriles, in particular phthalodinitriles, are prepared from an appropriately alkyl-substituted aromatic hydrocarbon by catalytic oxidation with oxygen or an oxygen-containing gas in the presence of ammonia at elevated temperatures in the vapor phase, in the presence of a catalyst which contains from 2 to 10% by weight of vanadium(V) oxide, from 1 to 10% by weight of antimony(III) oxide, from 0.02 to 2% by weight of an alkali metal oxide and alumina, by a process in which from 0.01 to 1.0% by weight of an alkaline earth metal, or of a compound of an alkaline earth metal, in particular barium or a barium compound, is added to the catalyst.

Abstract: Hexamethylenemine is obtained by hydrogenating .epsilon.-caprolactam, the latter being vaporized and hydrogenated under a working pressure of less than 10 bar, the gas phase being unsaturated in respect of caprolactam, and the residence time being short.

Abstract: 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.

Abstract: A pyridine or a pyrrole is obtained in a one-stage process directly from an .alpha.,.omega.-dinitrile of appropriate carbon skeleton when the dinitrile is reacted in the gas phase with hydrogen, over a hydrogenation catalyst.

Abstract: Amines are N-alkylated by reaction with an alcohol or a carbonyl compound in the presence of hydrogen under atmospheric pressure in the gas phase over a catalyst, containing copper and aluminum, which is obtained by heating and reducing a basic precipitate of salts of copper and aluminum.

Abstract: A hydrogenation catalyst containing copper, nickel or cobalt as the active metal is obtained by precipitating the metal salt solution with an alkali metal silicate solution containing excess alkali, and drying and reducing the resulting precipitate.