摘要:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
摘要:
A continuous process for the preparation of O—, S— and N-alkenyl compounds by reaction of the corresponding OH, SH or NH compound with an acetylene in the liquid phase in the presence of basic alkali or alkaline earth metal compounds at from 40 to 300° C. and from 0.11 to 5 MPa absolute comprises continuously feeding the corresponding OH, SH or NH compound and the acetylene and operating at a conversion of the corresponding OH, SH or NH compound of ≧90%.
摘要:
Unsubstituted or alkyl-substituted THF is obtained by catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or their derivatives using a catalyst comprising 20% by weight, preferably >30% by weight, in particular from 35 to 90% by weight, of an oxidic support having acid centers, at a hot spot temperature of from 240 to 310° C., preferably from 240 to 280° C., and a WHSV over the catalyst of from 0.01 to 1.0, preferably from 0.02 to 1, in particular from 0.05 to 0.5, kg of starting material/l of catalyst x hour.
摘要:
A process for preparing N-alkenyl-amides by reacting the corresponding NH-amides with acetylenes in the liquid phase in the presence of basic alkali metal compounds and of a cocatalyst comprises using as the cocatalyst compounds of the general formulae (Ia) and/or (Ib) R1O—(CH2CH2CH2CH2O)n—H (Ia): R1O—(CH2CH2CH2CH2O)n—R2, (Ib): where n is 1, 2 or 3 and R1 and R2 are independently C1- to C6-alkyl or C2- to C6-alkenyl, or together a butenyl unit.
摘要:
A process for purifying alkenyl compounds having a divalent or trivalent heteroatom in the &agr;-position relative to the double bond by distillation comprises carrying out at least two distillations in which the purified alkenyl compounds are obtained from the gas phase by condensation, where the time between the first distillation after the synthesis of the alkenyl compounds and at least one further distillation is at least one day and the purified alkenyl compounds have an APHA color number of
摘要:
A dialdehyde, trialdehyde or tetraldehyde or at least two thereof as aldehyde are hydrogenated by bringing into contact at least: the aldehyde; a catalyst comprising at least one metal selected from the group consisting of nickel, cobalt and copper in chemically bound and/or elemental form; hydrogen; at a gas pressure in the range from 5 to 350 bar and a temperature in the range from 40 to 300° C.
摘要:
The invention relates to a process for the separation of maleic anhydride from the maleic anhydride-containing reactor offgases from the preparation of maleic anhydride by the oxidation of hydrocarbons, in which this gas stream is brought into contact with a high-boiling, inert absorbent for maleic anhydride and maleic anhydride is separated from the resultant liquid absorbate phase by vapor stripping, where the stripping agent used is an alcohol, and at least some of the maleic anhydride is reacted with the alcohol to give the ester.
摘要:
A process for the preparation of n-butyraldehyde and/or n-butanol, wherein a) 1,3-butadiene is caused to react with an alcohol of the formula I ROH I, to form a mixture of adducts of the formulas II ##STR1## and III ##STR2## b) the adduct III is isomerized to the adduct II, c) the adduct II is isomerized in the presence of a homogeneous or heterogeneous transition metal element catalyst to form the enol ether of the formula IV ##STR3## and d) n-butyraldehyde and/or n-butanol is/are produced from this ether IV by the reaction thereof with hydrogen and water or water only in the presence of a homogeneous or heterogeneous catalyst.
摘要:
The present invention relates to a mixture comprising itaconic acid or an itaconic acid derivative and a primary amine of the formula (I) R—NH2 (I) where the molar ratio of primary amine to itaconic acid or the itaconic acid derivative is in the range from 0.5:1 to 20:1, wherein the mixture comprises 50 mole percent or less of 4-carboxypyrrolidones of the formula (II), derivatives of the 4-carboxypyrrolidones of the formula (II) and 4-carbamidopyrrolidones of the formula (III) based on the itaconic acid used or the itaconic acid derivative used and in which R is a linear or branched saturated aliphatic radical having 1 to 24 carbon atoms or a saturated cycloaliphatic radical having 3 to 24 carbon atoms. The invention further provides for the use of the inventive mixtures for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones, and also a process for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones.In addition, the present invention relates to mixtures comprising 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones and 1,3-alkylmethylpyrrolidines, where the proportion of 1,3-alkylmethylpyrrolidines is in the range from 10 to 10 000 ppm, and to mixtures comprising 1,3-alkylmethylpyrrolidone and 1,4-alkylmethylpyrrolidone, wherein the molar ratio of 1,3-alkylmethylpyrrolidone to 1,4-alkylmethylpyrrolidone is in the range from 1:1 to 10:1.