PROCESS FOR PRODUCING CARBOXYLIC ACID DERIVATIVE.

摘要

A process for producing a carboxylic acid derivative represented by general formula [VIII], (wherein R<1>, R<2>, R<3> and L are each as defined in the specification), which comprises reacting a benzyl halide with a cyano compound to give a phenylacetonitrile, reacting the nitrile with an alkyl nitrite in the presence of a base to give an alpha -hydroxyiminophenylacetonitrile, reacting the hydroxy nitrile with an alkylating agent to give an alpha - alkoxyiminophenylacetonitrile, hydrolyzing the alkoxy nitrile in the presence of a base, optionally after hydration and acid treatment, to give an alpha -alkoxyiminophenylacetic acid, and finally reacting the acid with a halogenating agent, or converting the acid into a corresponding metal salt and reacting the salt with an alkylating agent, or reacting the acid with a lower alcohol in the presence of an acidic catalyst. According to this process, the reactions can be advanced through the respective steps under mild conditions, and the target derivative [VIII] can be produced even without resort to high-pressure steam equipment, high-temperature heat medium equipment, refrigerator, and so forth. Further, this process is advantageous in that only a single solvent will suffice without the necessity for using various solvents according to the respective steps. <CHEM>