摘要:
Preparation of heterocyclic aldehydes I ##STR1## (A, B=optionally substituted methylene groups; m, n=1 to 5; m+n>2), by hydrogenation of carboxylic acids IIa ##STR2## or one of their esters IIb derived from a C.sub.1 -C.sub.10 alcohol, at a temperature of from 200.degree. to 450.degree. C. over a catalyst. The end products are suitable as intermediates for herbicides of the cyclohexanone class.
摘要翻译:PCT No.PCT / EP95 / 02071 Sec。 371日期1997年2月20日 102(e)日期1997年2月20日PCT提交1995年5月31日PCT公布。 WO95 / 33741 PCT出版物 日期1995年12月14日杂环醛的制备(I)(A,B =任选取代的亚甲基; + E,不同m + EE,+ E,不n + EE = 1〜5; + E, m + EE ++ E,uns n + EE> 2),通过羧酸IIa(IIa)或其衍生自C1-C10醇的酯IIb中的一种在200°至450°的温度下氢化 在催化剂上。 最终产品适合作为环己酮类除草剂的中间体。
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 continuously preparing a primary aromatic amine by reacting a corresponding cycloaliphatic alcohol with ammonia in the presence of hydrogen at a temperature in the range from 80 to 350° C. in the presence of a heterogeneous catalyst, wherein the catalytically active composition of the catalyst, before its reduction with hydrogen, comprises from 90 to 99.8% by weight of zirconium dioxide (ZrO2), from 0.1 to 5.0% by weight of oxygen compounds of palladium and from 0.1 to 5.0% by weight of oxygen compounds of platinum.
摘要:
Novel supported, titanized chromium catalysts for the homopolymerization of ethylene and the copolymerization of ethylene with α-olefins, a process for preparing them and to their use for the polymerization of olefins.
摘要:
Process for polymerizing at least one olefinic monomer selected from ethylene, propylene and 1-butene in a loop reactor in the presence of a polymerization catalyst at from 20 to 150° C., but below the melting point of a polymer to be formed, and a pressure of from 43 to 80 bar, where the polymer formed is present in a suspension in a liquid or supercritical suspension medium and wherein the suspension is circulated by means of an axial pump, wherein the polymerization is carried out at an average solids concentration in the reactor of more than 53% by weight, in the case of continuous product discharge, and at an average solids concentration in the reactor of more than 45% by weight, in the case of discontinuous product discharge, and wherein the polymerization is carried out at an ethylene concentration of at least 10 mol %, based on the suspension medium.
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 process for preparing pyrroles of the formula I: ##STR1## where R.sub.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and are hydrogen atoms, alkyl groups having from 1 to 12 carbon atoms or cycloalkyl groups having from 3 to 12 carbon atoms, by dehydrogenation of pyrrolidines of the formula II: ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, in the presence of a supported noble metal catalyst is described. In this process, the dehydrogenation is carried out at from 150 to 300.degree. C. and pressures of from 0.01 to 50 bar and the noble metal catalyst comprises from 30 to 100% by weight of:a) palladium on an oxide of a rare earth or an oxide of an element of the 4.sup.th group (transition group IV) of the Periodic Table, orb) a platinum/palladium mixture on aluminum oxide, an oxide of a rare earth or an oxide of an element of the 4.sup.th groupand from 0 to 70% by weight of alkali metal oxide or alkaline earth metal oxide.
摘要:
The disclosure is a process for preparing a phthalide of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently of the others hydrogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy, by hydrogenation of a phthalic anhydride of the general formula II ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each as defined above, with the aid of a hydrogenation catalyst, which comprises performing the hydrogenation with the aid of a nickel catalyst doped with metals of subgroup 1, subgroup 6 and/or subgroup 7 of the Periodic Table.
摘要:
Aromatic aldehydes are prepared by catalytically reacting aromatic carboxylic acids or their esters with hydrogen in the gas phase at from 200.degree. to 450.degree. C. and from 0.1 to 20 bar in the presence of a zirconium dioxide/lanthanide catalyst having a high BET surface area of from 20 to 150 m.sup.2 /g, preferably from 40 to 150 m.sup.2 /g. The proportions by weight of the catalytically active mass range from 80 to 99.9% by weight of zirconium dioxide and from 0.01 to 20 %by weight of one or more lanthanide elements. This catalyst provides very high conversion rates of 94 to 100% together with a correspondingly high selectivity for the aldehyde product.
摘要:
A process for the preparation of a phenyl amine which may be substituted by alkyl or cycloalkyl in which the corresponding cyolohexylamine is reduced at temperatures of 150.degree. to 300.degree. C. and pressures of 0.01 to 50 bar in the presence of a heterogeneous dehydrogenation catalyst consisting essentially of palladium or a palladium/platinum mixture supported on carrier consisting of the oxides of rare earth metals and and metals of Group IVb of the Periodic Table of Elements, with the proviso that the palladium/platinum mixture may also be supported on an alumina carrier. The cyclohexylamine reactant can be advantageously prepared by reacting the corresponding phenol with ammonia and hydrogen at 100.degree. to 250.degree. C. in the presence of the same heterogeneous catalyst as a preliminary step to provide a two stage process using the same catalyst in both stages.