Abstract: The present invention relates to a process for preparing 3-(2-hydroxybenzoyloxy)-4-(trimethylammonio)butyrobetaine hydrochloride of formula (I), wherein the process comprises reacting 3-hydroxy-4-(trimethylammonio)butyrobetaine or a salt thereof with a 2-alkoxybenzoyl chloride of formula (III), and where R is selected from benzyl and branched C3-C6 alkyl groups. The present invention further relates to compounds of formula (II) and salts thereof, where R is selected from benzyl and branched C3-C6 alkyl groups, and to a process for preparing same.

Abstract: The present invention relates to a process for preparing 3-(2-hydroxybenzoyloxy)-4-(trimethylammonio)butyrobetaine hydrochloride of formula (I), wherein the process comprises reacting 3-hydroxy-4-(trimethylammonio)butyrobetaine or a salt thereof with a 2-alkoxybenzoyl chloride of formula (III), and where R is selected from benzyl and branched C3-C6 alkyl groups. The present invention further relates to compounds of formula (II) and salts thereof, where R is selected from benzyl and branched C3-C6 alkyl groups, and to a process for preparing same.

Abstract: (±)-&agr;-(Difluoromethyl)-ornithine is separate into its isomers using (−)-O,O′-di-p-toluoyl-L-tartaric acid. (−)-&agr;-(Difluoromethyl)-ornithine monohydrochloride monohydrate and in particular the (−)-isomer are inhibitors of ornithine decarboxylase and thereby have numerous pharmacological actions.

Abstract: Starting from 5-alkylidene or 5-benzylidenetetramic acid optically-active 4-amino-3-hydroxy-carboxylic acids are produced in the (rel-3R,4R) configuration, especially statine. The synthesis process includes the O-acylation of the tetramic acid to the corresponding 4-acyloxy-3-pyrrolin-2-one, a stereoselective hydrogenation to (rel-4R,5R)-4-acyloxy-5-alkyl or 5-benzylpyrrolidin-2-one and an enantioselective enzymatic hydrolysis of the (4R,5R)-enantiomer to the corresponding 4-hydroxypyrrolidin-2-one. The nonhydrolyzed enantiomer is separated and converted into the target compound with (3S,4S) configuration by hydrolytic cleavage of the lactam ring and the ester function and optionally introduction of an amino protective group. Analogously the (3R,4R)-enantiomer can be obtained from the 4-hydroxypyrrolidin-2-one from the enzymatic hydrolysis. The 4-amino-3-hydroxycarboxylic acids producible according to the invention are the structural elements of enzyme inhibitors.

Abstract: Starting from 5-alkylidene or 5-benzylidenetetramic acid, optically-active 4-amino-3-hydroxy-carboxylic acids are produced in the (rel-3R,4R) configuration, especially statine. The synthesis process includes the O-acylation of the tetramic acid to the corresponding 4-acyloxy-3-pyrrolin-2-one, a stereoselective hydrogenation to (rel-4R,5R)-4-acyloxy-5-alkyl or 5-benzylpyrrolidin-2-one and an enantioselective enzymatic hydrolysis of the (4R,5R)-enantiomer to the corresponding 4-hydroxypyrrolidin-2-one. The nonhydrolyzed enantiomer is separated and converted into the target compound with (3S,4S) configuration by hydrolytic cleavage of the lactam ring and the ester function and optionally introduction of an amino protective group. Analogously the (3R,4R)-enantiomer can be obtained from the 4-hydroxypyrrolidin-2-one from the enzymatic hydrolysis. The 4-amino-3-hydroxycarboxylic acids producible according to the invention are the structural elements of enzyme inhibitors.

Abstract: 4-Akylthiomethyl-2-aryl-2H-1,2,3-triazoles and 4-arylthiomethyl-2-aryl-2H-1,2,3-triazoles are produced from .gamma.-chloroacetoacetyl chloride, aryldiazonium salts and thiolates. In a first step, the aryldiazonium salt is reacted with the chloroacetoacetyl chloride to the corresponding 3-chloropyruvaldehyde-arylhydrazone, which is converted with the thiolate into the corresponding 3-alkylthio or 3-arylthiopyruvaldehyde-arylhydrazone. The 3-alkylthio or 3-arylthiopyruvaldehyde-arylhydrazone is cyclized with hydroxylamine-O-sulfonic acid to the desired 2-aryl-2H-1,2,3-triazole.

Abstract: The enantiomers of 2,2-dimethylcyclopropanecarboxylic acid are separated by esterification with the hydroxy group of optically active mandelic acid methyl ester, crystallization of the diastereomeric esters and subsequent hydrolysis of the diastereomeric esters.

Abstract: Acetylsalicylic acid esters of carnitine are distinguished relative to acetylsalicylic acid. The esters can be produced by acetylation of suitable salicylic acid esters of carnitine.

Abstract: Salicylic acid esters of carnitine are distinguished relative to acetylsalicylic acid by high water solubility, low toxicity and good stomach tolerance. The compounds are obtainable in three stages from carnitine hydrochloride and o-methoxybenzoyl chloride.

Abstract: The enantiomers of 2,2-dimethylcyclopropanecarboxylic acid are separated by salt formation with optically active 1-(3-methoxyphenyl)-ethylamine, fractional crystallization of the diastereomeric salts and subsequent decomposition of the salts with a strong acid.

Abstract: A process for the production or R,S-2,2-dimethylcyclopropanecarboxylic acid starting from isobutylene oxide and a phosphonoacetic acid trialkyl ester. In this way, first the R,S-2,2-dimethylcyclopropanecarboxylic acid-C.sub.1 -C.sub.4 alkyl ester is formed, which then is hydrolyzed to the corresponding acid. R,S-2,2-Dimethylcyclopropanecarboxylic acid is an important intermediate product for the production of S-(+)-2,2-dimethylcyclopropanecarboxamide.

Abstract: Process for the production of thiotetronic acid wherein 4-chloroacetoacetic acid chloride is reacted with hydrogen sulfide in the presence of an amine.

Abstract: A process for the production of 5-alkyl tetramic acids from 4-alkoxy-3-pyrrolin-2-ones and aldehydes or ketones. By basic catalysis, 5-alkylidene-4-alkoxy-3-pyrrolin-2-ones are first formed, which are converted into the target compounds by cleavage of the alkoxy group and catalytic hydrogenation.

Abstract: Process for the production of thiotetronic acid wherein 4-chloroacetoacetic acid chloride is reacted with hydrogen sulfide in the presence of an amine.

Abstract: A process for the production of 5-alkyl tetramic acids from 4-alkoxy-3-pyrrolin-2-ones and aldehydes or ketones. By basic catalysis, 5-alkylidene-4-alkoxy-3-pyrrolin-2-ones are first formed, which are converted into the target compounds by cleavage of the alkoxy group and catalytic hydrogenation.

Abstract: Highly pure thiotetronic acid is produced from 4-alkoxy-2(5) thiophenones.

Abstract: Process for the production of 4-alkoxy-2(5H) thiophenones, which are suitable as intermediate products, i.e., for the production of highly pure thiotetronic acid.

Abstract: Process for the production of 4-alkoxy-2(5H) thiophenones, which are suitable as intermediate products, i.e., for the production of highly pure thiotetronic acid.

Abstract: 4-Benzyloxy-3-pyrrolin-2-on-1-yl acetamide is an advantageous intermediate product for the production of pharmaceutically effective 4-hydroxypyrrolidin-2-1-yl acetamide. Processes for the production of the intermediate product as well as the active substance are described.

Abstract: 4-Benzyloxy-3-pyrrolin-2-on-1-yl acetamide is an advantageous intermediate product for the production of pharmaceutically effective 4-hydroxypyrrolidin-2-1-yl acetamide. Processes for the production of the intermediate product as well as the active substance are described.