摘要:
Alcohols are prepared by the catalytic hydrogenation of the corresponding carbonyl compounds at elevated temperatures and at superatmospheric pressure in the liquid phase by a process in which the catalyst used contains copper on an SiO2-containing carrier in the presence or absence of one or more of the elements magnesium, barium, zinc and chromium.
摘要:
Cobalt catalysts whose catalytically active material comprises from 55 to 98 wt % of cobalt, from 0.2 to 15 wt % of phosphorus, from 0.2 to 15 wt % of manganese, and from 0.2 to 15 wt % of alkali metal, calculated as oxide, in which the catalyst material is calcined in a first step at final temperatures of from 550.degree. to 750.degree. C. and in a second step at final temperatures of from 800.degree. to 1000.degree. C., and a process for the hydrogenation of organic nitriles and/or imines, in which the novel cobalt catalyst is used.
摘要:
A process is disclosed for preparing D,L-aspartic acid by beating aqueous solutions of ammonium salts of the maleic acid. The molar ratio of maleic acid to ammonia ranges from 1:1 to 1:50. The process is carried out at temperatures from 60.degree. to 250.degree. C. and pressures of at least 1 bar. The pressure applied during the reaction is adjusted to ensure that the reaction mixture is almost completely present in liquid phase. Excess ammonia is removed and the reaction solution is acidified so as to release D,L-aspartic acid, which is then isolated.
摘要:
A process for the preparation of polyalcohols comprises the stages:(a) Reaction of an alkanal or ketone with formaldehyde in aqueous solution in the presence of a tertiary amine, to form a formates containing polyalcohol product mixture,(b) removal of water, excess tertiary amine, excess formaldehyde(c) heating of remaining mixture from (b) with removal of further formaldehyde and tertiary amine with formation of the formates of the polyalcohol,(d) transfer of tertiary amine removed from stage (b) and/or from stage (c), to synthesis stage (a) and/or to the subsequent transesterification stage (e),(e) transesterification of the resulting formates of the polyalcohol from stage (c) with an alcohol of the formula ROH in the presence of a transesterification catalyst to give polyalcohols and formates of the formula ##STR1## where R is a hydrocarbon radical, preferably alkyl of 1-6, particularly preferably 1-2, carbon atoms, and(f) isolation of the polyalcohols.
摘要:
Cyclopentanones of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each an organic radical or R.sup.1 or R.sup.2 may be hydrogen and R.sup.3 is hydrogen or formyl, are prepared by a process in which a 2-formyl-3,4-dihydropyran of the general formula II ##STR2## where R.sup.1 and R.sup.2 have the abovementioned meanings, a) where R.sup.3 is formyl, is converted in the presence of an acidic heterogeneous catalyst at from 50.degree. to 500.degree. C., andb) where R.sup.3 is hydrogen,b.sub.1) is reacted with water or an alcohol in the presence of an acidic heterogeneous catalyst at from 100.degree. to 500.degree. C. in the gas phase orb.sub.2) a compound II or an acrolein of the general formula III ##STR3## is reacted with water or with water in the presence of an acid or with an alcohol in the presence of an acid at from 150.degree. to 400.degree. C. in the liquid phase. Novel 2-formylcyclopentanones are obtained.
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 aminopropionitriles of the general formula I ##STR1## in which R denotes hydrogen or methyl, wherein ammonia is caused to react with an acrylonitrile of the general formula II ##STR2## In which the substituent has the aforementioned meanings, in a molar ratio of from 1:1 to 500:1 over a heterogenic catalyst at temperatures ranging from 40.degree. to 180.degree. C. and pressures ranging from 10 to 350 bar.