Patent ID: 6689885
Filing Date: 2004-02-10
Classification: C07D

Abstract:
A process for preparing a compound of formula I wherein R1 isa linear of branched alkyl radical having 1 to 10 carbon atoms, in which one or two CH2 groups are optionally each replaced by a â€”CH&boxH;CHâ€” group, a cycloalkyl radical or cycloalkylalkylene radical having 5 to 12 carbon atoms, or a phenyl radical or phenylmethyl radical wherein the radicals are mono substituted with COOH, COOA, CONH2, CONHA, CON(A)2 or CN, wherein A is an alkyl group having from 1 to 6 carbon atoms,comprising reacting a 2-aminobenzothiophene-3-carboxylic ester of formula II wherein R2 is a linear or branched alkyl group having 1 to 6 carbon atoms, with a nitrile of formula IIINâ‰¡Câ€”R1 â€ƒâ€ƒIII wherein R1 has the above meaningin solution or suspension in a solvent in the presence of an acid, wherein an excess of the acid is dissolved in the solvent, and subsequently the 2-aminobenzothiophene-3-carboxylic ester of formula II and the nitrile of the formula III are added.