摘要:
In a process for preparing carbonyl compounds of the formula ##STR1## where R.sup.1 is a hydrogen atom or an alkyl radical having from 1 to 3 carbon atoms, R.sup.2 is a hydrogen atom or a radical of the formula ##STR2## where R.sup.3 is a hydrogen atom or together with R.sup.4 is an oxygen atom, R.sup.4 is the radical OR.sup.6 or together with R.sup.3 is an oxygen atom, R.sup.5 is a hydrogen atom, an alkyl radical having from 1 to 8 carbon atoms or a cyclohexyl or cyclopentyl radical and R.sup.6 is an alkyl radical having from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula --CH.sub.2 --CHO or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CHO, by gas-phase oxidation of methanol or alcohols of the formula ##STR3## where R.sup.1 and R.sup.5 are as defined above and R.sup.7 is a hydrogen atom or a radical OR.sup.8 and R.sup.8 is a hydrogen atom, an alkyl radical having from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical for the formula --CH.sub.2 --CH.sub.2 --OH or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --OH, using an oxygen-containing gas in the presence of copper- and/or silver-containing catalysts and an amount of a phosphorus compound which is volatile under the reaction conditions which is such that the amount of phosphorus (calculated as P) is up to 20 ppm, based on the weight of alcohol used, the phosphorus is introduced within the catalyst bed.
摘要:
The present invention relates to a process for the preparation of carbonyl compounds of the formula ##STR1## in which R.sup.1 denotes a hydrogen atom or an alkyl radical containing from 1 to 3 carbon atoms, R.sup.2 denotes a hydrogen atom or a radical of the formula ##STR2## in which R.sup.3 denotes a hydrogen atom or, together with R.sup.4, an oxygen atom, R.sup.4 denotes the radical OR.sup.6 or, together with R.sup.3, an oxygen atom, R.sup.5 denotes a hydrogen atom or an alkyl radical containing from 1 to 8 carbon atoms or a cyclohexyl or cyclopentyl radical, and R.sup.6 denotes an alkyl radical containing from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula--CH.sub.2 --CHO or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CHO,by gas-phase oxidation of methanol or alcohols of the formula ##STR3## in which R.sup.1 and R.sup.5 have the meanings specified above and R.sup.7 denotes a hydrogen atom or a radical OR.sup.8, and R.sup.8 denotes a hydrogen atom, an alkyl radical containing from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula --CH.sub.2 --CH.sub.2 --OH or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --OH, using an oxygen-containing gas in the presence of a (copper and/or silver)-containing catalyst and a phosphorus compound which is volatile under the conditions of the reaction and is present in an amount such that the weight of phosphorus (calculated as P), based on the weight of alcohol used, is not more than 20 ppm, wherein the amount of phosphorus used is divided into at least two portions, of whicha) the first portion is added together with the mixture of gaseous starting materials before this reaches the catalyst bed andb) at least one further portion is added within the catalyst bed.
摘要:
The present invention relates to a process for preparing hydrocyanic acid (HCN) by catalytic dehydration of gaseous formamide in a reactor which has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to a reactor for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide, which reactor has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to the use of the reactor of the present invention in a process for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide.
摘要:
Carbonyl compounds of the formula where R1 is a hydrogen atom or an alkyl radical having from 1 to 3 carbon atoms, R2 is a hydrogen atom, an unsubstituted or C1-C3-alkyl-monosubstituted to -trisubstituted C2-C4-alkenyl radical or a radical of the formula where R3 is a hydrogen atom or together with R4 is an oxygen atom, R4 is the radical OR6 or together with R3 is an oxygen atom, R5 is a hydrogen atom, an alkyl radical having from 1 to 8 carbon atoms, an unsubstituted or C1-C3-alkyl-monosubstituted to -trisubstituted C2-C4-alkenyl radical or a cyclohexyl or cyclopentyl radical and R6 is an alkyl radical having from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula —CH2—CHO or —CH2—CH2—O—CH2—CHO, are prepared by gas-phase oxidation of methanol or alcohols of the formula where R1 and R5 are as defined above, by means of an oxygen-containing gas in the presence of copper- and/or silver-containing catalysts, the catalyst system used comprising at least one phosphorus-containing copper- and/or silver-containing catalyst.
摘要:
The present application relates to a process for preparing a solution of cyanide salts, comprising the steps of: a) preparing a crude gas comprising hydrocyanic acid by dehydrating formamide up to a formamide conversion of ≧97%; b) if appropriate, acid-scrubbing the crude gas obtained in step a); c) subsequently reacting the crude gas obtained in step a) or, if appropriate, in step b) with an aqueous solution of a hydroxide, M(OH)x, where M is selected from the group consisting of alkali metals and alkaline earth metals and x is dependent upon the oxidation state of M and is 1 or 2.
摘要:
The present invention relates to a process for preparing hydrocyanic acid (HCN) by catalytic dehydration of gaseous formamide in a reactor which has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to a reactor for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide, which reactor has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to the use of the reactor of the present invention in a process for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide.
摘要:
Pyrroles are prepared by a process in which ammonia or an amine is reacted with a but-2-ene-1,4-diol in the presence of a supported catalyst containing copper, silver, zinc, palladium, nickel, cobalt and/or platinum and/or compounds of these metals as catalytic materials, and in the presence or absence of compounds of chromium and/or manganese as additional catalysts, in the gas phase.The pyrroles obtainable by the process of the invention are useful starting materials for the preparation of dyes, corrosion inhibitors, drugs and pesticides.
摘要:
In a process for the preparation of methylglyoxal dimethyl acetal from methylglyoxal and methanol in the presence of an acidic ion exchanger, water is introduced in an amount sufficient to form an acidic reaction mixture in which the acetal product and water form an azeotropic mixture, with or without the retention of some methanol reactant. After subjecting a single phase acidic reaction mixture to an azeotropic distillation, it will separate into two distinct liquid phases with a simple recovery of the acetal product from the aqueous phase.
摘要:
A process for the hydrogenation of an aromatic compound, in which at least one hydroxyl group is attached to an aromatic core, or an aromatic compound, in which at least one amino group is attached to an aromatic core, in the presence of a catalyst containing, as active metal, ruthenium and optionally one or more other Group IB, VIIB, or VIIIB metals, applied to a macroporous support.