Bayer Aktiengesellschaft

Erich Wolters

Alexander Klausener

Heinz U Blank

Heinz Landscheidt

Stefan Antons

Andreas Schulze Tilling

Lothar Puppe

Guido Steffan

Eberhard Zirngiebl

Udo Birkenstock

Otto Neuner

Joerg-Dietrich Jentsch

Norbert Langenfeld

Norbert Lui

Dieter Dieterich

Karlfried Wedemeyer

Paul Wagner

Nikolaus Muller

Gerhard Marzolph

Heinz-Ulrich Blank

Bernhard Beitzke

Zoltan Kricsfalussy

Friedrich-Wilhelm Ullrich

Lutz Frohn

Karl-Wilhelm Henneke

Gunter Silber

Konrad Hable

Michael Herzhoff

Bernd Pennemann

J&ouml;rg-Dietrich Jentsch

Gunter Rottloff

Karl W Muller

Halmut Kraus

Eberhard Zirngbiebl

Bernd Lenders

Method for producing catalysts containing ruthenium and the use thereof for hydrogenation

The invention relates to a process for the preparation of optically active alcohols from optically active carboxylic acids by reducing an optically active carboxylic acid with hydrogen in the presence of a catalyst comprising ruthenium and at least one further metal or transition metal having an atomic number in the range of from 23 to 82.

Method for producing optically active alcohols

The invention relates to a process for preparing optically active amino alcohols from optically active amino acids by reducing an optically active amino acid with hydrogen in the presence of a ruthenium-containing catalyst and an acid.

Method for producing optically active amino alcohols

Process for producing 2-fluorine-1-cyclopropane carboxylic acid

Unsubstituted or substituted 2-fluoro-pyrimidines can be prepared by reaction of the underlying 2-amino-pyrimidines with diazotization agents, mixtures of HF and H.sub.2 O containing 30-70% by weight of HF, based on the total of HF and H.sub.2 O, serving as reaction medium. The reaction medium can also contain diluents and/or inorganic salts, preferably fluorides.

Process for the preparation of substituted 2-fluoro-pyrimidines

Dimethyl carbonate (DMC) is prepared by continuous gas reaction of carbon monoxide and methyl nitrite a heterogeneous catalyst comprising a platinum at 50.degree. to 170.degree. C. under 1 to 5 bar.

Process for the preparation of dimethyl carbonate

Dimethyl carbonate is obtained with a high selectivity and great constancy over time by reacting carbon monoxide with methyl nitrite in a continuous gas phase reaction in the presence of a heterogeneous catalyst prepared by the application to a suitable support of one or more palladium compounds of the formula

Dialkyl carbonates can be prepared by reacting carbon monoxide with alkyl nitrites in a continuous gas phase reaction in the presence of a heterogeneous platinum metal catalyst, the activity of this catalyst being maintained by the addition of small amounts of halogen. The dialkyl carbonates are thus formed with almost quantitative selectivity and no deactivation of the catalyst occurs.

Process for the preparation of dialkyl carbonates

Dialkyl carbonates can be prepared by reaction of carbon monoxide with alkyl nitrites in a continuous gas-phase reaction using a platinum metal catalyst on a metal phosphate support and adding hydrogen halide stepwise or continuously during the course of the reaction in almost quantitative selectivity; the corresponding dialkyl oxalates are formed in such small amounts that in most cases they cannot be detected.

Process for preparing dialkyl carbonates

Dialkyl carbonates can be prepared by the reaction of carbon monoxide with alkyl nitrites in a continuous gas phase reaction, using a platinum group metal catalyst on an alumosilicate zeolite having acidic centers, preferably in the H.sup.+ form, as a support, which catalyst may optionally comprise additional material of a compound of antimony, bismuth, aluminum, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel or a mixture of a plurality of these, and hydrogen halide being added in the course of the reaction intermittently or continuously. In this reaction, the dialkyl carbonates are formed with almost quantitative selectivity; the corresponding dialkyl oxalates cannot be detected in most cases.

Dialkyl carbonates can be prepared by the reaction of carbon monoxide with alkyl nitrites in a continuous gas phase reaction, using a platinum metal catalyst on an amorphous alumosilicate having a content of 30-80 atom% Al, based on the sum of Al and Si, as a support, which catalyst may optionally comprise additional material of a compound of antimony, bismuth, aluminium, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel or a mixture of a plurality of these, and hydrogen halide being added in the course of the reaction intermittently or continuously. In this reaction, the dialkyl carbonates are formed with almost quantitative selectivity; the corresponding dialkyl oxalates cannot be detected in most cases.

Dialkyl carbonates can be prepared by reaction of carbon monoxide with alkyl nitrites in a continuous gas phase reaction, in which a platinum metal catalyst of oxidic or hydroxidic compounds of elements from group Vb of the Periodic Table (Mendeleev) as supports and, if desired, addition of an antimony, bismuth, aluminium, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel compound or a mixture of a plurality thereof on this catalyst are used, and the hydrogen halide which is discharged from the reactor together with the reaction mixture is batchwise or continuously replaced in the course of the reaction. This results in the formation of dialkyl carbonates in almost quantitative selectivity; the corresponding dialkyl oxalates can, in most cases, not be detected.

Dialkyl carbonates can be prepared by reaction of carbon monoxide with alkyl nitrites in continuous gas phase reaction, in which a platinum metal halide catalyst on aluminum oxides, aluminum oxide hydrates or aluminum hydroxides as support and, if desired, an additive comprising an antimony, bismuth, aluminum, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel compound or a mixture of a plurality thereof on this catalyst are used and hydrogen halide is replaced during the course of the reaction batchwise or continuously in at least the amount which is discharged from the reactor together with the reaction mixture. This results in the formation of dialkyl carbonates in almost quantitative selectivity, while the corresponding dialkyl oxalates can not in most cases be detected. The abovementioned supports are characterized by a BET surface area of more than 1 m.sup.2 /g.

.beta.-Amino-acrylic acid esters of the formula

Process for the preparation of .mu.-amino-acrylic acid esters

Acid halides of the formula (R.sup.1, R.sup.2, R.sup.3)C--CO--Hal are obtained by reacting alkyl halides of the formula (R.sup.1, R.sup.2, R.sup.3)C--Hal with carbon monoxide under a pressure of 5 to 1,000 bar and at a temperature of -20.degree. C. to +100.degree. C. in the presence of 0.001 to 0.3 mol of AlCl.sub.3 and/or FeCl.sub.3, if appropriate in the presence of a further Bronsted or Lewis acid, per mol of the alkyl halide. The process is carried out, if desired in the presence of a solvent which is customary for Friedel-Crafts or Friedel-Crafts-related reactions and, if appropriate in the presence of a hydrogen halide. The acid chloride can be isolated from the reaction mixture or further reacted.

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Koln, Germany

Erich Wolters