PROCESS FOR PRODUCING SODIUM SALT OF 2- (Z-HYDROXY-IMINO) PHENYL ACETONITRILE BY ISOMER TRANSFORMATION

摘要

During preparation of 2-(Z-hydroxy-imino)-phenyl-aceto-nitrile-sodium salt of general formula Z(1), 2-(hydroxy-imino)-phenyl-aceto-nitrile sodium salt (having an arbitrary isomeric ratio) is uniformly transformed into the Z isomer. Transformation takes place in a protic solvent, or in a solvent mixt. that contains a protic solvent. Associated crystallisation runs in parallel with isomerization. During preparation of 2-(Z-hydroxy-imino)-phenyl-aceto-nitrile-sodium salt of general formula Z(1), 2-(hydroxy-imino)-phenyl-aceto-nitrile sodium salt (having an arbitrary isomeric ratio) is uniformly transformed into the Z isomer. Transformation takes place in a protic solvent, or in a solvent mixt. that contains a protic solvent. Associated crystallisation runs in parallel with isomerization. Transformation takes place in a suspension of 2-(hydroxy-imino)-phenyl-aceto-nitrile-sodium salt at pH 8.5-11, between 70 [deg]C and the reflux temp. of solvents used. Optionally water is removed with azeotropic distillation at the progress rate of reaction. Finally, the product is evaporated to dryness. Anhydrous or aqueous 2-5 aliphatic alcohol is used on its own, as a solvent, or mixed with apolar, aprotic solvents. Adicyclic or aromatic solvents served as apolar and aprotic solvents. Single step transformation occurs directly in the reaction mix where an oxime was prepared. with alkyl-nitrile. Resulting 2-(Z-hydroxy-imino)-phenyl-aceto-nitrile-sodium salt is used with advantage in preparation of oxabetrinil and phoxim.