摘要:
A process for preparing caprolactam by cyclization of 6-aminocapronitrile in the presence of water at elevated temperature and in the presence or absence of a catalyst and a solvent, comprises a) removing from the cyclization reaction effluent ("reaction effluent I") caprolactam and all components boiling higher than caprolactam ("high boilers"), b) treating the high boilers of stage a) with phosphoric acid and/or polyphosphoric acid at from 200 to 350.degree. C. to obtain a reaction effluent II, and c) removing caprolactam formed and any 6-aminocapronitrile from reaction effluent II of stage b) to obtain separation from unconverted high boilers and acid used.
摘要:
Polytetrahydrofuran or polytetrahydrofuran monoesters of C.sub.1 -C.sub.20 -monocarboxylic acids or polytetrahydrofuran monoethers of monohydric C.sub.1 -C.sub.20 -alcohols, having an average molecular weight of from 250 to 10,000 Dalton and liquid at room temperature, are prepared by the cationic polymerization of tetrahydrofuran in the presence of a telogen by a process in which tetrahydrofuran is polymerized in the presence of water, 1,4-butanediol and/or polytetrahydrofuran having an average molecular weight of from 200 to 700 Dalton and/or of a C.sub.1 -C.sub.20 -monocarboxylic acid and/or of a monohydric C.sub.1 -C.sub.20 -alcohol with the aid of a catalytic amount of a zeolite catalyst which has an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of from 4:1 to 100:1 and in which the population ratio P of the acid centers on the external surface of the zeolite to the total number of acid centers of the zeolite is 0.03/l or more.
摘要:
A process for preparing compounds of the formula I ##STR1## where: Y inter alia is ##STR2## where R.sup.3 is hydrogen or a C.sub.1 -C.sub.10 - hydrocarbon radical. R.sup.1 and R.sup.2, inter alia, are each, independently of one another, hydrogen, a C.sub.1 -C.sub.20 -hydrocarbon radical which optionally carries inert substituents or heteroaryl, wherein a compound of the formula II ##STR3## where Z is ##STR4## is reacted in the presence of catalytic amounts of a carbonic ester and of a nitrogenous base at from 100.degree. to 250.degree. C. under a pressure of from 0.01 to 100 bar.
摘要:
Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures in the presence of a catalyst in the gas phase by a process which comprises carrying out the hydrogenation with a catalyst based on at least one metal selected from the group consisting of nickel, cobalt, ruthenium and rhodium and with the proviso that the catalyst is not a powder.
摘要:
A process for the preparation of a 5-vinylpyrrolidone of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is hydrogen or alkyl and R.sup.3 is preferably hydrogen but may further represent alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl or a 5- to 6-membered aromatic or non-aromatic heterocyclic group containing 1 to 3 nitrogen atoms and/or an oxygen or sulfur atom, the process being carried out in two steps, first to react a 3-formylpropionic acid ester of the formula ##STR2## where each of R.sup.1 and R.sup.2 is hydrogen or C.sub.1 -C.sub.8 -alkyl, and R.sup.4 is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, with a vinylymagnesium halide of the formulaCH.sub.2 .dbd.CH--Mg--X V,where X is chlorine, bromine or iodine, at a temperature of from -30.degree. to 100.degree. C., under a pressure from 0.001 to 10 bar and in a molar ratio of V:IV of from 0.3:1 to 3:1 to obtain as an intermediate product a gamma-vinylbutyrolactone of the formula ##STR3## where R.sup.1 and R.sup.2 have the abovementioned meaning; and then reacting said intermediate of the formula II with ammonia or a primary amine of the formulaR.sup.3 --NH.sub.2 III,where R.sup.3 has the abovementioned meaning, at a temperature of from 150.degree. to 350.degree. C. and under a pressure of from 0.1 to 200 bar.
摘要:
A process for the preparation of 3-(2'-acyloxyethyl)-dihydro-2(3H)furanones of the general formula I ##STR1## in which R.sup.1 denotes C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.12 aralkyl, or C.sub.7 -C.sub.12 alkylaryl, in which a 3-(2'-oxyethyl)-dihydro-2(3H)furanone of the general formula II ##STR2## in which R.sup.2 denotes C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.12 aralkyl, or C.sub.7 -C.sub.12 alkylaryl is caused to react with a carboxylic acid, a carboxylic anhydride, and/or an acyl halide in the presence of an acid catalyst at temperatures of from 50.degree. to 250.degree. C. and pressures of from 0.1 to 100 bar.
摘要:
A process for the preparation of tetrahydropyran-4-carboxylic acid and esters thereof of the general formula I ##STR1## in which R.sup.1 denotes hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.8 cycloalkyl, or aryl by the reaction of a dihydro-2(3H)furanone of the general formula II ##STR2## in which R.sup.2 denotes hydrogen, C.sub.1 -C.sub.6 alkyl, or --CO--R.sup.3 andR.sup.3 denotes hydrogen or C.sub.1 -C.sub.6 alkyl, with water or an alcohol of the general formula IIIR.sup.1 --OH (III),in whichR.sup.1 has the aforementioned meaning,at temperatures ranging from 200.degree. to 350.degree. C. in the presence of a heterogenous acid catalyst, in which use is made of a fixed heterogenous acid catalyst.
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.