摘要:
A process for purifying crude piperidines of the formula I ##STR1## where R.sup.1 to R.sup.4 are C.sub.1 -C.sub.6 -alkyl, or R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 together are a CH.sub.2 -chain of 2 to 5 carbons, which comprises, in a first step, removing high-boiling substances and, if present, water from the crude piperidines by distillation; in a second step, adding from 0.01 to 5% by weight, based on the product of the first step, as a reducing agent; and, in a third step, isolating the piperidines by distillation.
摘要:
A process for the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine from 3-cyano-3,5,5-trimethylcyclohexanone which requires three spatially separated reaction spaces, in order to carry out the following three steps in sequence: a) reacting the 3-cyano-3,5,5-trimethylcyclohexanone with excess ammonia on acidic metal-oxide catalysts in a first reaction space at from 20.degree. to 150.degree. C. and from 50 to 300 bar, b) hydrogenating the resultant reaction products using hydrogen in a second reaction space in the presence of excess ammonia and preferably liquid ammonia on hydrogenation catalysts, optionally using basic components or on neutral or basic supports at from 50.degree. to 100.degree. C. and at from 50 to 300 bar, and c) hydrogenating the resultant reaction products in the presence of hydrogen and also ammonia in a third reaction space on hydrogenation catalysts, optionally using basic components or on neutral or basic supports at from 110.degree. to 160.degree. C. and at from 150 to 300 bar.These three steps in sequence provide a substantially complete reaction of the original 3-cyano-3,3,5-trimethylcyclohexanone reactant with a yield of 96% of the desired diamino product in which the cis-content of the diamine is 70%.
摘要:
A process for preparing cyclic lactams by reacting amino carbonitriles with water in liquid phase in the presence of heterogeneous catalysts based on titanium dioxide, zirconium oxide, cerium oxide and aluminum oxide.
摘要:
A process for preparing benzophenone imines of the general formula I ##STR1## where R.sup.1 to R.sup.6 are hydrogen, C.sub.1 -to C.sub.4 -alkoxy, C.sub.1 -to C.sub.2 -alkylamine or C.sub.2 -to C.sub.4 -dialkylamine, by reacting benzophenones of the general formula II ##STR2## where R.sup.1 to R.sup.6 have the abovementioned meanings, in liquid ammonia in the presence of oxides of the elements boron, aluminum, gallium, indium, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, scandium, yttrium, titanium, zirconium, vanadium, niobium, tantalum or mixtures thereof at from 50.degree. to 150.degree. C. and from 50 to 350 bar is described.
摘要:
Cyclic lactams are prepared by reacting amino carbonitriles with water in liquid phase in a fixed bed reactor in the presence of heterogeneous catalysts which have no soluble constituents under the reaction conditions.
摘要:
The preparation of 2-substituted but-2-ene-1,4-dial-4-acetals of the formula I ##STR1## in which the substituents R.sup.1 to R.sup.4 stand for hydrogen or C.sub.1 -C.sub.6 aliphatic radicals, and R.sup.2 and R.sup.3 or R.sup.1 and R.sup.2 are in each case common members of an aliphatic 4-membered to 7-membered ring, which can contain a hetero atom, and R.sup.5 denotes an alkyl, alkenyl, or alkynyl radical having from 1 to 12 C atoms, which can be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxy, ether, thioether, acyl, alkylamino, carboxy, or carbalkoxy groups, an optionally substituted aryl radical or an alkoxy, alkylthio, or acyloxy group, whereina) glyoxal is caused to react with a 1,3-propanediol of the formula II ##STR2## in aqueous solution in the presence of an acid to form a monoacetal of the formula III ##STR3## is neutralized, and if necessary the components more readily volatile than the monoacetal III are distilled off,b) the monoacetal III obtained is caused to react with an aldehyde R.sup.5 CH.sub.2 --CHO in the presence of from 0.01 to 10 mol %, based on glyoxal, of a catalyst mixture of a secondary amine and an acid to form an aldol of the formula IV ##STR4## the components which are more volatile than the aldol IV being distilled off if necessary, andc) the aldol IV is dehydrated in the presence of a water-eliminating agent to form the product I,and novel hemiacetals of glyoxal monoacetals.
摘要:
A process for the preparation of 3-cyano-3,5,5-trimethylcyclohexanone by the reaction of isophorone with hydrogen cyanide in the presence of quaternary ammonium catalysts at temperatures ranging from 80.degree. to 180.degree. C. and pressures ranging from 0.5 to 20 bar, in which the ammonium catalysts used are salts of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 denote C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.18 aralkyl or C.sub.2 -C.sub.18 hydroxyalkyl andX denotes HCO.sub.3 or ##STR2## with the proviso that R.sup.4 stands for C.sub.1 -C.sub.8 alkyl when X is ##STR3##
摘要:
Process for preparing a pentane-1,5-diamine of the formula ##STR1## where R.sup.1 represents a variety of organic radicals including alkyl which can bear substituents such as hydroxyl, halogen, alkoxy, carbalkoxy, carboxyl, alkylamino, cycloalkyl or aryl, andR.sup.2 and R.sup.3 independently of one another, represent hydrogen or have the same meanings as R.sup.1 or together are a C.sub.4 -C.sub.7 -alkylene chain which is unsubstituted or substituted by one to five C.sub.1 -C.sub.4 -alkyl groups,which comprises:(a) reacting a .gamma.-cyanoketone of the formula ##STR2## where R.sup.1, R.sup.2 and R.sup.3 have the meanings given above, with excess ammonia in a first reaction space on an acidic heterogeneous catalyst at 20.degree.-150.degree. C. and 15-500 bar, and(b) hydrogenating the resulting reaction product in a second separate reaction space in the presence of excess ammonia on a cobalt, nickel or noble metal catalyst at 50.degree.-180.degree. C. and 30-500 bar.Novel pentane-1,5-diamines are obtained, in which R.sup.1 must contain at least two carbon atoms if R.sup.2 and R.sup.3 are both hydrogen. These new compounds containing two primary amine groups possess advantageous properties of lower volatility and also greater asymmetry (with different reactivity of the two amine functions). They provide useful curing agents for epoxides and act as improved components of polyamides.
摘要:
A process for the preparation of a 2,2-disubstituted pentane-1,5-diamine of the formula I ##STR1## where R.sup.1 and R.sup.2, independently of one another, are C.sub.1 - to C.sub.10 -alkyl or C.sub.2 - to C.sub.10 -alkenyl or together are a C.sub.4 - to C.sub.7 -alkylene chain which is unsubstituted or monosubstituted to pentasubstituted by C.sub.1 - to C.sub.4 -alkyl, from a 2,2-disubstituted 4-cyanobutanal of the formula II ##STR2## where R.sup.1 and R.sup.2 are as defined above, comprises, in two spatially separate reaction spaces,a) reacting the 4-cyanobutanal of the formula II, in a first reaction space, with excess ammonia on an acidic heterogeneous catalyst at from 20.degree. to 150.degree. C. and at from 15 to 500 bar, andb) hydrogenating the resultant reaction product, in a second reaction space, using excess hydrogen in the presence of excess ammonia on a catalyst containing cobalt, nickel, ruthenium and/or another noble metal, if desired with a basic component or on a basic or neutral carrier, at from 60.degree. to 150.degree. C. and at from 50 to 500 bar.
摘要:
A process for the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine having a cis/trans isomer ratio of at least 70:30 bya) imination of 3-cyano-3,5,5-trimethylcyclohexanone with ammonia in the presence of an imination catalyst at temperatures of from 20.degree. to 150.degree. C. and pressures of from 1.5 to 30 MPa to form 3-cyano-3,5,5-trimethylcyclo-hexanone imine followed byb) hydrogenation of the 3-cyano-3,5,5-trimethylcyclohexanone imine in the presence of ammonia over a catalyst containing copper and/or a Group VIII metal at a temperature of from 80.degree. to 160.degree. C. and under a pressure of from 5 to 30 MPa,wherein the catalytic hydrogenation of the 3-cyano-3,5,5-trimethylcyclohexanone imine is carried out in the presence of an acid used in an amount such as to give an acid number of from 0.1 to 2, based on 3-cyano-3,5,5-trimethylcyclohexanone used.