Huels Aktiengesellschaft

Degussa Aktiengesellschaft

Degussa-Huels Aktiengesellschaft

Wolfgang Kleemiss

Marcel Feld

Manfred Kaufhold

Frank Bauer

Guenther Koehler

Udo Jegelka

Manfred Neumann

Klaus-Dieter Steffen

Michael Korell

Thomas Kalz

Bruno Klotz-Berendes

Enantiomerically enriched malonic acid monoesters substituted by a tertiary hydrocarbon radical, and their preparation

Process for preparing amino derivatives of C-H-acid compounds

Process for the preparation of amino acid derivatives

2-Hydroxybenzonitrile is prepared by passing 2-hydroxybenzamide in the gas phase over a heterogeneous catalyst thereby effecting dehydration of the 2-hydroxybenzamide to produce 2-hydroxybenzonitrile.

Process for the preparation of 2-hydroxybenzonitrile

The invention relates to a process for the preparation of methoxyacetic acid esters in which a chloroacetic acid ester is reacted with an alkali metal methoxide to give the methoxyacetic acid ester.

Process for the preparation of methoxyacetic acid esters

Cyclopropylamine is prepared from butyrolactone by a process comprising:

Process for the preparation of cyclopropylamine

Aminoacetic acid esters of formula I in which R.sup.1, R.sup.2 and R.sup.3 are identical or different hydrocarbon radicals, or any two of these radicals form a carbon ring with the carbon atom to which they are attached and R.sup.4 is hydrogen or an alkyl radical having 1-4 carbon atoms, are prepared by reacting an .alpha.-substituted malonic acid monoamide ester of formula II ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the meanings above, by the Hofmann degradation reaction, with a hypohalite in an amount of up to 1.5 equivalents in an aqueous-basic medium containing base in an amount of 0.8-1.5 equivalents per mol. of starting malonic acid monoamide ester II.

Process for the preparation of amino acetic acid esters with a tertiary

A process for preparing high-purity cyclopropyl methyl ketone from compositions which contain cyclopropyl methyl ketone, 4,5-dihydro-2-methylfuran, addition products of 4,5-dihydro-2-methylfuran by a continuous rectification process in which at least a portion of the composition to be purified is introduced into a rectification apparatus via a side feed located above the bottom portion of the apparatus.

Process for preparing high-purity cyclopropyl methyl ketone

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 process for the preparation of aminoacetic acids or aminoacetonitriles with a tertiary hydrocarbon radical in the .alpha.-position in which monoamide derivatives of malonic acid are subjected to a Hofmann rearrangement.

Process for the preparation of aminoacetic acids with a tertiary

A process for preparing hydroxymethylcyclopropane, in which formylcyclopropane is hydrogenated over copper chromite, zinc chromite and/or copper/zinc catalysts. The process may be batchwise or continuous.

Process for preparing hydroxymethylcyclopropane

A process for the preparation of cyclopropanamine by Hofmann degradation of cyclopropanecarboxamide, comprising the following steps:

Process for the preparation of cyclopropanamine

In a process for the preparation of cyclopropanecarboxamide by amidating cyclopropanecarboxylic esters with ammonia in alcoholic solution at from 60.degree. to 200.degree. C., the reaction being catalyzed by an alcoholate of a monohydric alcohol, high yields are achieved even in the absence of a hydrocarbon solvent when a cyclopropanecarboxylic ester of the formula ##STR1## in which R is C.sub.1 - to C.sub.3 -alkyl or cyclopropyl, is employed.

Process for the preparation of cyclopropanecarboxamide

The present invention relates to a novel process for preparing 1-aminocyclopropanecarboxylic acid hydrochloride (ACC.multidot.HCl) of the formula ##STR1## ACC.multidot.HCl is prepared from a cyclopropane-1,1-dicarboxylic acid diester via an 1-aminocarbonylcyclopropanecarboxylic acid ester intermediate and an alkali metal salt or alkaline earth metal salt of 1-aminocarbonylcyclopropanecarboxylic acid. The process represents a simplification and gives improved product yields.

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Haltern, Germany

Wolfgang Kleemiss