Bayer Aktiengesellschaft

Gunter Stammann

Johann Grolig

Helmut Waldmann

Robert Becker

Christian Rasp

Zoltan Kricsfalussy

Harald Medem

Joachim Schneider

Catalysts for the gas-phase reduction of aromatic nitro compounds to aromatic amines are regenerated by treatment of the catalyst, at elevated temperature, with a gas mixture which contains oxygen, inorganic and/or organic amines and/or nitrogen oxides and, where appropiate, steam.

Process for the regeneration of catalysts for the gas-phase reduction of

The invention relates to a process for the production of substituted polyarylethers from par-substituted phenols.

Process for the production of substituted polyaryl ethers

Urethanes are made by reacting an organic nitro compound with an organic compound containing at least one hydroxyl group in the presence of carbon monoxide, hydrogen and a catalyst system. The carbon monoxide and hydrogen are used in quantities such that the molar ratio of CO to H.sub.2 is from 0.3:1 to 3:1. The catalyst system is made up of at least one noble metal or compound of a noble metal from Group VIIIB of the Periodic System of Elements, at least one organic nitrogen base and a co-catalyst combination of iron or copper oxidic or hydroxidic compound and a chloride compound. The product urethanes are useful in the production of isocyanates and pesticides.

Process for the production of urethanes

Urethanes are made by reacting a primary amine with carbon monoxide and a compound containing at least one hydroxyl group in the presence of an oxidizing agent and a catalyst system. The catalyst system is made up of (i) a noble metal and/or a noble metal compound of a metal of the Eighth Secondary Group of the Periodic System of Elements and (ii) an oxidizing quinoid and/or a compound capable of being converted to an oxidizing quinoid compound under the reaction conditions. The catalyst system may optionally include (iii) metal compounds of elements of the Third to Fifth Main Groups and/or First to Eighth Secondary Groups of the Periodic System of Elements and/or (iv) a tertiary amine. This reaction is generally carried out at a temperature of from 100.degree. to 300.degree. C. and at a pressure of from 5 to 500 bars. The product urethanes are useful in the production of isocyanates and pesticides.

The invention relates to a process for the preparation of carbonic acid esters with high selectivity and under reaction conditions which permit high space/time yields, said process being one in which an alcohol is allowed to react with a mixture of molecular oxygen and carbon monoxide in the liquid phase in the presence of a catalyst system containing copper, chemically bonded oxygen, chemically bonded halogen and at least one nitrogen base.

Process for the preparation of carbonic acid esters

A urethane is produced by reacting an organic nitro compound with carbon monoxide and an organic compound containing at least one hydroxyl group in the presence of a catalyst and a co-catalyst. This reaction is conducted in the liquid phase at elevated temperature and pressure. The catalyst employed is an element and/or compound of an element from the group of noble metals of the 8th Secondary Group of the Periodic Table. The co-catalyst used is formed from (1) a component taken from the group consisting of iron oxychloride, a mixture of iron compounds containing iron oxychloride and oxide-chloride combinations and (2) metallic iron or an iron alloy in finely divided or high surface form. The oxides which may be used in the oxide-chloride combinations of co-catalyst component (1) are the oxides and/or oxide hydrates of tetravalent tin, trivalent chromium, hexavalent molybdenum, hexavalent tungsten, pentavalent vanadium, divalent iron and trivalent iron. The chlorides which may be used in this oxide-chloride combination are chlorides of the elements of Groups IIIA, IVA, VA and IB to VIIIB of the Periodic Table and/or hydrochlorides of tertiary amines.

Production of urethanes by the oxycarbonylation reaction of N,N'-disubstituted ureas and organic compounds containing at least one hydroxyl group with carbon monoxide in the presence of molecular oxygen and/or organic nitro compounds and a catalyst system comprising (a) a noble metal and/or noble metal compound of the eighth subgroup of the periodic system of elements and (b) a compound of an element and/or elements of the third to fifth main group and/or first to eighth subgroup of the periodic system of elements characterized in that said compounds are capable of undergoing Redox reactions under the reaction conditions.

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Cologne, Germany

Gunter Stammann