Abstract: 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° 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.

Abstract: The invention relates to enantiomerically enriched malonic acid monoesters &agr;-monosubstituted by a tertiary hydrocarbon radical, or their salts, of the general formula I: in which R1, R3, R4 and R5 are identical or different hydrocarbon radicals, and wherein any two of the radicals R3, R4 and R5 may alternatively be present as a carbocyclic ring together with the quaternary carbon atom which they substitute, and M is hydrogen, one equivalent of a metal or an optionally substituted ammonium ion. The invention further relates to a process for the preparation of the enantiomerically enriched &agr;-monosubstituted malonic acid monoesters, or their salts, by enzymatic partial hydrolysis of the corresponding diesters.

Abstract: A process for preparing potassium monoethyl malonate by selective saponification of malonic acid diethyl ester with potassium hydroxide, in which the potassium hydroxide is added to the malonic acid diethyl ester, malonic acid diethyl ester and potassium hydroxide are used in a molar ratio of at least 1.5 and the potassium hydroxide is effectively distributed into the malonic acid diethyl ester.

Abstract: Process for the preparation of amino acid derivatives of the general formula I where R1-R4 are as defined herein, from the corresponding malonic acid monoester amides of the general formula II  by Hofmann degradation using a hypohalite in an aqueously basic medium, which comprises carrying out the reaction in the presence of an alcohol or amine and using the hypohalite in amounts of from 1.0 to 1.5 equivalents and the base in amounts of from 0.8 to 4.0 equivalents per mole of starting material II.

Abstract: A process for preparing potassium monoethyl malonate by selective saponification of malonic acid diethyl ester with potassium hydroxide, in which the potassium hydroxide is added to the malonic acid diethyl ester, malonic acid diethyl ester and potassium hydroxide are used in a molar ratio of at least 1.5 and the potassium hydroxide is effectively distributed into the malonic acid diethyl ester.

Abstract: A three-stage process for removing mercury contaminants from alcoholic alkali metal alkoxide solutions is provided, in which mercury is depleted in a first filtration through inert fibrous material, followed by a second filtration through pulverized coal, and then by concentration by distillation, to preferably provide a mercury content below 0.1 ppm.

Abstract: 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.

Abstract: The invention relates to a process for the preparation of a macrocyclic ester of the general formula: in which m is an integer from 6 to 14 and n is an integer from 2 to 12.

Abstract: Cyclopropylamine is prepared from butyrolactone by a process comprising:(a) reacting butyrolactone with hydrogen chloride, thereby yielding chlorobutyric acid, (b) esterifying said chlorobutyric acid with a primary or secondary alcohol having 4-8 carbon atoms, (c) cyclizing the ester with an alkali metal alcoholate of a primary alcohol having 1-3 carbon atoms to give a mixture of cyclopropanecarboxylic acid esters, (d) converting the cyclopropanecarboxylic acid ester mixture into cyclopropanecarboxylic acid amide by reacting the ester mixture with ammonia, and (e) reacting said cyclopropanecarboxylic acid amide with hypohalite ion in a basic medium, thereby forming cyclopropylamine.

Abstract: A process for nitrosating C-H-acidic compounds. The process substantially avoids producing polluted wastewater.

Abstract: The invention relates to a process for the preparation of aminomalonic acid esters and optionally their salts by the catalytic hydrogenation of a substituted malonic acid ester in an inert solvent, and optionally by the addition of an acid to the hydrogenation mixture. The process comprises carrying out the hydrogenation in the presence of a solid dehydrating agent and a solvent or solvent mixture in which the aminomalonic acid ester salt is substantially insoluble.

Abstract: 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.

Abstract: 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.

Abstract: Process for the preparation of macrocyclic compounds by condensation of at least difunctional compounds and subsequent thermal depolymerization in the presence of catalysts, wherein thermal depolarization is carried out in solvent of the formula ##STR1## where R.sup.1 and R.sup.2 represent identical or different aliphatic C.sub.1-6 hydrocarbon radicals with or without functional groups and having number average molecular weights (Mn) from 500 to 3,000, from which the value of n inevitably follows, at a pressure of less than 50 hPa and at a temperature of 200 to 300.degree. C., 5 to 1,000 parts by weight of solvent being used per part by weight of macrocyclic compound.

Abstract: The invention relates to a novel process for the simultaneous preparation of cyclopropyl alkyl ketones and 4,5-dihydroalkylfurans from 3-acyltetrahydrofuran-2-ones using a metal salt according to the diagram ##STR1## In the reaction, N-alkyllactams and/or N-acylmorpholines which are high-boiling and only slightly miscible with water are used. By charging the solvent, the metal salt and the 3-acyltetrahydrofuran-2-one in a molar excess with respect to the metal salt, heating the mixture to 160.degree. to 220.degree. C. and metering in further 3-acyl-tetrahydrofuran-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.

Abstract: 3-Amino-5-methylpyrazole is prepared by reaction of cyanoacetone or an alkali metal salt thereof with hydrazine, a hydrazinium salt, or hydrazine hydrate.

Abstract: 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.

Abstract: Alkali metal salts of cyanoacetone are prepared by reacting an acetonitrile, an acetic acid ester and an alkali metal alkoxide without distilling off the alcohol formed during the reaction. The reaction products are obtained with high yields and high purity.

Abstract: For the preparation of 2-cyanoacetoxypropionic esters, a mixture of lactic ester and cyanoacetic ester is introduced, an alkali metal alcoholate is added as catalyst and the mixture is heated while the alcohol eliminated during the course of the reaction is distilled off. The course of the reaction is followed by means of gas chromatographic analysis and the reaction is terminated prior to eliminating the theoretical amount of alcohol by destroying the catalyst by acidification. The reaction mixture is worked up by distillation and the product easily separated from the reaction mass due to the substantial absence of high boiling components.

Abstract: Sodium thiobarbiturate is prepared by reacting dimethyl malonate, thiourea and sodium methylate in methanol as the solvent at elevated temperatures, preferably at reflux temperature under atmospheric pressure.