Huels Aktiengesellschaft

Chemische Werke Huls Aktiengesellschaft

Degussa Aktiengesellschaft

Degussa-huels Aktiengesellschaft

Chemische Werke Huels Aktiengesellschaft

Naarden International N.v.

Huels Atiengesellschaft

Manfred Kaufhold

Marcel Feld

Renate Paulczynski

Wolfgang Kleemiss

Josef Metz

Udo Jegelka

Wolfgang H Muller

Moustafa El-Chahawi

Werner Otte

Manfred Zur Hausen

Horst-Dieter Wulf

Johann Gaube

Thomas Keil

Michael Korell

Kerstin Bodmann

Artur Hunds

Wilfried Buschken

Oliver Meyer

Erhard Lange

Thomas Kalz

Peter Bickert

Gerhard Menzel

Hendrik J Takken

Manuela Imig

Slagmulder Andre

Andre Slagmulder

Jürgen Fieker

Bernd Helpap

Werner Smolka

Harald Kett

Gottfried Bankwitz

Michael Beuth

Dieter Hepp

Guenther Kohler

Werner Jacquemin

The present invention is directed to a process for the synthesis of monoalkylated C&#x2014;H acidic methylene group-containing compounds, such as malonic esters, and malonic ester nitriles.

Process for monoalkylation of C-H acidic methylene groups

Cyclopropanecarboxylates of lower alcohols are prepared by esterification of the corresponding cyclopropanecarboxylic acids with the corresponding lower alcohols in the presence of an acid catalyst, while maintaining a considerable stoichiometric excess of the cyclopropanecarboxylic acid with respect to the lower alcohol, keeping the temperature at from 100 to 200&deg; C. and distilling off the cyclopropanecarboxylate together with the water of reaction and small amounts of alcohol. Cyclopropanecarboxylates of lower alcohols are valuable intermediates in the pharmaceutical and agrochemical sectors.

Process for preparing cyclopropanecarboxylates of lower alcohols

Process for the preparation of 3-alkoxyacrylonitrile

The invention relates to a process for the preparation of 1,2,3,6-tetrahydro 2,2,6,6-tetramethylpyridine N-oxide by the catalytic oxidation of 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine, wherein 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine is oxidized with hydrogen peroxide in an aqueous medium in the presence of an alkaline earth metal salt or hydroxide as catalyst. The product is a polymerization inhibitor for monomers.

Process for the preparation of 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine N-oxide

A process for the preparation of 1,3-dichloropropane by reacting bis( -hydroxypropyl)ether with hydrogen chloride, optionally in the presence of tertiary basic nitrogen compounds or other tertiary aliphatic bases as catalysts, distilling off the 1,3-dichloropropane and the water of reaction and working up the two phases.

Process for the preparation of 1,3-dichloropropane

Process for the preparation of cyclooctanol

Cyanoacetamide is prepared without additional catalyst by esterification of crude cyanoacetic acid with a monohydric alcohol which forms an azeotrope with water and has 4 to 10 carbon atoms, reacting the resulting ester with ammonia in the presence of a basic catalyst to give cyanoacetamide, and work-up by a mechanical separating operation and a thermal treatment.

Process for preparing cyanoacetamide

The invention relates to a novel method for preparing cyclopropanecarboxylic acids by acidolysis of the corresponding esters, using an alkylbenzenesulfonic acid represented by the formula: ##STR1## as the reaction catalyst, where m+n is 5 to 15. Process-engineering improvements and simplifications are achieved with this process.

Method for preparing cyclopropanecarboxylic acids

Cyclopropylamine is prepared from butyrolactone by a process comprising:

Process for the preparation of cyclopropylamine

The invention relates to a process for preparing 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine from 4-hydroxy-2,2,6,6-tetramethylpiperidine in which 4-hydroxy-2,2,6,6-tetramethylpiperidine is dehydrated at elevated temperature in the gas phase over a solid acid catalyst.

Process for preparing 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine

Cyclopropyl alkyl ketones are separated from 3-acyltetrahydrofuran-2-ones by adding an alcohol, water or a water/alcohol mixture to a reaction product containing C.sub.1-4 -alkyl cyclopropyl ketone and 4,5-dihydro-2-alkylfuran by-product and an acid catalyst and reacting the by-product with the added alcohol, water of water/alcohol mixture before, during or after distilling said reaction product; and effectively separating C.sub.1 -.sub.4 -alkyl cyclopropyl ketone from reaction by-products. In the preparation of cyclopropyl alkyl ketones from 3-acyltetrahydrofuran-2-ones very reactive 4,5-dihydro-2-alkylfurans are also produced. By reacting such compounds with nucleophilic compounds, such as alcohols or water, before, during or after distillation of the reaction products, it is possible reliably to separate off the 4,5-dihydro-2-alkylfurans as high-boiling addition compounds. The offgas which is produced in the production process for cyclopropyl alkyl ketones can be simply and reliably purified by reactive washing. The byproducts, which are difficult to handle for a production process, can thus be reliably eliminated.

Process for the preparation of cyclopropyl alkyl ketones

A method for the continuous production of esters of thermally unstable acids by the esterification, with or without a catalyst, of the acids with alcohols is provided. The method involves esterification at temperatures of approximately 80.degree. C. to approximately 130.degree. C., essentially in a single reaction zone, to which the acid and an excess of alcohol are continuously supplied and from which a vapor stream containing alcohol and water produced by the esterification reaction are removed, while at the same time removing an ester-rich liquid reaction mixture from the single reaction zone, from which the ester is obtained.

Method for the continuous production of esters of thermally unstable

The polymerization of a vinylaromatic or vinylaliphatic compound at elevated temperature in the absence of air is inhibited by processing the vinylaromatic or vinylaliphatic compound in the presence of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl or 4-acetylamino-2,2,6,6-tetramethylpiperidine-N-oxylalone or in admixture with p-nitrosophenol or 2-methyl-4-nitrosophenol.

Inhibition of polymerization of vinylaromatic or vinylaliphatic

The invention relates to a novel process for simultaneously preparing cyclopropyl alkyl ketones and 4,5-dihydroalkylfurans from 3-acyltetrahydrofuran-2-ones in the presence of a metal salt according to the scheme ##STR1## during the reaction, high-boiling poly (ethylene glycol) dialkyl ethers are then used. By introducing the solvent, the metal salt and the 3-acyltetrahydrofuran-2-one in a molar excess to the metal salt, heating the mixture to 160.degree. to 220.degree. C. and adding further 3-acyltetrahydrofuran-2-one, the desired products are obtained in high yields. The metal salt can, moreover, be recovered in a simple manner by washing with water.

Process for preparing cyclopropyl alkyl ketones and 4,5-dihydroalkyfurans

Growing community of inventors

Marl, Germany

Manfred Kaufhold