Hoechst Aktiengesellschaft

Georg Schaeffer

Gunther Semler

Werner Spielmann

Franz Landauer

Siegfried Pietzsch

Klaus Warning

Karl Waldmann

Siegfried Planker

Rudolf Lademann

Klaus Schmiedel

Herbert Kuckertz

Siegfried Bildstein

Gunter H Herbst, Deceased

Ulrike M Herbst

Bettina S Herbst

Alwin Topp

Process for the preparation of 2-nitro-3-aminopyridine, and the

Carbamoyl chlorides derived from secondary aliphatic amines having alkyl groups which are branched in the 1-position are prepared by passing phosgene at an elevated temperature into the corresponding, initially taken--if appropriate dissolved in an inert solvent--secondary aliphatic amines having alkyl groups which are branched in the 1-position. The reaction products are intermediates in various specialized fields, particularly in the plant protection sector.

Process for the preparation of carbamoyl chlorides derived from

p-Hydroxyphenylacetic acid is prepared by reduction of p-hydroxymandelic acid with HI in the presence of red phosphorus. According to a preferred embodiment, the reaction is carried out in one vessel in which the mandelic acid is prepared in situ from phenol and glyoxylic acid.

Process for the manufacture of p-hydroxyphenyl-acetic acid

Diphenyl ethers are prepared by Ullmann reaction of alkali metal phenolates with halobenzenes in the presence of basic copper carbonate and/or copper salts of lower aliphatic carboxylic acids as catalysts. These special catalysts have a better catalytic activity than other copper catalysts known for the Ullmann reaction. The diphenyl ethers prepared or obtainable according to the invention are mainly intermediates in diverse fields such as pharmaceuticals or plant protecting agents.

Process for the preparation of diphenyl ethers

Thiochloroformates are prepared by reaction of mercaptans with phosgene in the presence of carboxylic acid amides and/or urea derivatives as catalysts in amounts smaller than hitherto known for this application. The amounts range from about 0.02 to 0.2 mol %, relative to the corresponding starting mercaptan. Despite the small amounts of catalyst the reaction proceeds as with the use of larger catalyst amounts; however, work-up is simplified and the product yields are increased in most cases.

Process for the preparation of thiochloroformates

Phenylacetic acid and the simple derivatives thereof are prepared by catalytic hydrogenation of mandelic acid and its appropriate derivatives in the presence of a noble metal catalyst in aqueous solution which is free from mineral acid, especially free from hydrochloric acid.

Process for the manufacture of phenylacetic acid and simple derivatives

p-Tert.butylbenzotribromide and the derivatives thereof which is halogen-substituted at the nucleus are prepared under side chain halogenation conditions by bromination of p-tert.butyltoluene and its derivatives substituted at the nucleus by halogen. Practically no undesired bromination in the nucleus or at the tert.butyl radical takes place. By partial saponification of the benzotribromide the corresponding benzoyl bromide is obtained. Further saponification of the latter or complete saponification of the benzotribromide yields p-tert.butylbenzoic acid and derivatives thereof which are halogen substituted at the nucleus, the esters of which can be used in pharmacology.

P-Tert.butylbenzotribromide and p-tert.butylbenzoyl bromide and process

p-tert.Butylbenzaldehyde and the derivatives thereof which are halogen-substituted at the nucleus are prepared by bromination of p-tert.butyltoluene and the derivatives thereof which are correspondingly halogen-substituted at the nucleus under side-chain halogenation conditions until the benzal bromide is obtained which is then saponified. Practically no undesired bromination at the nucleus or the tert.butyl group takes place. The products obtained are valuable intermediates for the manufacture of pharmaceutical agents, plant protecting agents and dyestuffs.

Process for the manufacture of para-tert.butylbenzaldehyde and its

Ketones are prepared by reacting carboxylic acid halides, in particular carboxylic acid chlorides, with aluminum-alkyl compounds, optionally in the presence of an aluminum trihalide, in methylene chloride as the solvent, at a temperature between about 20.degree. and about 100.degree. C., preferably between about 30.degree. and about 60.degree. C., more preferably of about 40.degree. C. which is the reflux temperature of the methylene chloride. When operating at a temperature above approximately 40.degree. C., pressure higher than atmospheric is applied. The reaction mixture is worked up in usual manner, suitably by decomposition with water followed by distillation.

Process for the manufacture of ketones

The waste water being formed upon the preparation of hydroxy aromatics, preferably of resorcinol and .beta.-naphthol, by caustic alkaline melt of the corresponding aryl-sulfonic acids or aryl sulfonates is purified by wet oxidation with oxygen or oxygen-containing gases at temperatures of from about 100.degree. to 370.degree. C. and under a pressure of from about 1 to 300 bars. The COD-decomposition rates amount to about 90% and more. When a hydroxy aromatic is prepared by means of a caustic soda melt, this process provides a sulfate, especially sodium sulfate, which is of sufficient purity for further use without complementary purification stages. The obtention of the pure salt is important for the economy of the process.

Process for the purification of waste water

Preparation of naphthalene-monosulfonic acids from naphthalene and sulfuric acid at elevated temperatures.

Process for the manufacture of naphthalene-monosulfonic acids

A process for the preparation of chloroformic acid aryl-esters and cyclic carbonates of aryl compounds containing at least two phenolic hydroxy groups wherein aromatic compounds containing one or more hydroxy groups linked to an aromatic nucleus, are reacted with phosgene in the presence of catalytic amounts of N,N-disubstituted acid amide either under pressure or without pressure while removing the hydrogen chloride continuously from the reaction mixture. This improved process results in almost quantitative or very high yields of pure products and avoids problems such as disposal of waste water.

Process for the preparation of chloroformic acid aryl esters and cyclic

Anhydrous organic solutions of alkali metal arylates are prepared by dissolving an alkali metal arylate or reacting an arylhydroxy compound with alkali metal hydroxide in a ketone immiscible or incompletely miscible with water at room temperature and removing the water from the solution, if any, by azeotropic distillation with reflux.

Process for the manufacture of anhydrous alkali metal arylate solutions

Process for preparing carboxylic acid chlorides by reaction of carboxylic acids or carboxylic anhydrides with phosgene at temperatures of from 0.degree. to 180.degree.C in the presence of a catalyst, wherein 0.01 to 10 weight percent, calculated on the carboxylic acid or the carboxylic anhydride, of trisubstituted phosphine oxides or trisubstituted phosphine sulfides or reaction products of these compounds with phosgene and/or acids or acid anhydrides or mixtures of these compounds are used as catalyst.

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Hofheim am Taunus, Germany

Georg Schaeffer