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

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

Abstract: The present invention provides a process, which includes: preparing 3-alkoxyacrylonitrile from 3,3-dialkoxypropionitrile by catalytically eliminating alcohol from 3,3-dialkoxypropionitrile in the presence of at least one aromatic sulfonic acid catalyst and at least one high-boiling solvent. Another embodiment of the invention provides a method of producing a pharmaceutical compound, which includes the above-described process. Another embodiment of the invention provides a method of producing a cosmetic product, which includes the above-described process.

Abstract: 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.

Abstract: A process for the preparation of 1,3-dichloropropane by reacting bis(3-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.

Abstract: The present invention provides a process, which includes:

Abstract: A process for the preparation of cyclooctanol from cyclooctene comprising: a. reaction of cyclooctene with formic acid in the absence of an added catalyst to produce a two-phase reaction mixture containing cyclooctyl formate and residual formic acid, b. separation of the two phases into a lower phase rich in formic acid (phase A) and an upper phase low in formic acid (phase B), c. extraction of cyclooctyl formate from phase A to obtain an extract, d. combination of phase B and the extract from phase A, e. distillative work-up of the combination of phase B and the extract from phase A in an apparatus fitted with a short distillation path to obtain crude cyclooctyl formate, and f. catalytic transesterification of the cyclooctyl formate of said crude cyclooctyl formate with an alcohol to produce cyclooctanol.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Preparation of 4-acylamino-2,2,6,6-tetramethylpiperidines from 4-amino-2,2,6,6-tetramethylpiperidine and acid anhydrides carried out in the presence of carboxylic acids, whereupon the carboxylic acid is eliminated, using water at elevated temperature, from the initially formed carboxylate salt of the 4-acylamino-2,2,6,6-tetramethylpiperidine. In this process, no salt-like by-products arise.

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: A process for preparing unsaturated ethers of the formula (1) ##STR1## from acetals or ketal of the formula (2) ##STR2## is improved by heating the acetals or ketals at from 100.degree. to 250.degree. C. in a high-boiling, branched carboxylic acid and obtaining the unsaturated ether as a distillate. The process, which is insensitive to contaminants, gives the unsaturated ether in high yields.