Dsm Fine Chemicals Austria Gmbh

Syngenta Crop Protection, Inc.

Dsm Fine Chemicals Austria Nfg Gmbh & Co. Kg

Dsm Chemie Linz Gmbh

Syngenta Participations Ag

Christian Burger

Wolfram Hendel

Antonia Praus

Peter Pochlauer

Gerald Summer

Harald Poschko

Anita Lamplmayr

Gerhard Steinbauer

Klaus Reiter

Engelbert Kloimstein

Eduard Perndorfer

Johann Altreiter

Sylvia Krich

Peter Pojarliev

Karl Heinz Giselbrecht

Birgit Zw&ouml;lfer

Birgit Zwölfer

A process for preparing racemic alkyl-5-halopent-4-enecarboxylic acids and esters thereof of the formula (I), in which R is a C-C-alkyl radical, Ris H or C-alkyl and X is chlorine, bromine or iodine, which comprises a) reacting a dialkyl alkylmalonate of the formula (II),in which R is as defined above and Ris a C-C-alkyl radical, in the presence of a metal alkoxide of the formula MOR, in which M may be Na, K or Li, and Ris a C-C-alkyl radical, and in an organic solvent, with 1,3-dihalopropene to give the corresponding allylated malonate, then b) after full conversion, adding an inorganic salt and a C-Calcohol to the reaction mixture, heating the reaction mixture to reflux temperature, then c) isolating the desired racemic ester of the formula (I) from the reaction mixture by extraction or direct distillation and d) if the racemic acid is the desired end product, hydrolyzing the ester function. 

Process for preparing racemic alkyl-5-halopent-4-enecarboxylic acids or carboxylic esters

A process for the preparation of 2-chloro-5-chloromethyl-1,3-thiazole, in which allyl isothiocyanate of formula CH &boxH;CH&mdash;CH &mdash;NCS is reacted at from &minus;40&deg; C. to &plus;30&deg; C., in a solvent that is inert under the reaction conditions, with from 1 to 2 mol of a chlorinating agent per mol of allyl isothiocyanate; to the reaction mixture so obtained there is added, at a reaction temperature of from 0&deg; C. to the boiling temperature of the solvent used, from 1 to 5 mol of oxidising agent per mol of allyl isothiocyanate, and then 2-chloro-5-chloromethyl-1,3-thiazole is isolated from the reaction mixture and is optionally converted by crystallisation into high-purity 2-chloro-5-chloromethyl-1,3-thiazole.

Method for producing 2-chloro-5-chloromethyl-1,3-thiazole

Process for preparing glyoxylic esters or their hydrates in which a water-soluble salt of a maleic or fumaric monoester or a mixture thereof is reacted with ozone in aqueous solution at temperatures of from 0 to 50.degree. C., and the corresponding glyoxylic ester or its hydrate is isolated from the resulting reaction mixture.

Process for preparing glyoxylic esters and their hydrates

Process for the preparation of carboxylic acid succinimidyl esters by reaction of N-hydroxysuccinimide with a carboxylic acid and a halophosphoric acid ester of the formula ##STR1## in which R.sub.1 and R.sub.2 are identical or different and are a C.sub.2 - to C.sub.6 -alkyl radical or a phenyl radical, or R.sub.1 and R.sub.2 together form a C.sub.6 -aryl radical, in the presence of a base in a diluent at a temperature of 0.degree. C. up to 100.degree. C. and isolation of the corresponding carboxylic acid succinimidyl ester.

Process for the preparation of carboxylic acid succinimidyl esters

A process for the preparation of carboxylic acid succinimidyl esters by reaction of N-hydroxysuccinimide with a carboxylic acid and a halophosphoric acid ester of the formula ##STR1## is desired, in which R.sub.1 and R.sub.2 are identical or different and are a C.sub.2 - to C.sub.6 -alkyl radical or a phenyl radical, or R.sub.1 and R.sub.2 The process is carried out in the presence of a base in a diluent at a temperature of 0.degree. C. up to 100.degree. C. with isolation of the corresponding carboxylic acid succinimidyl ester.

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Christian Burger