Verfahren zur Herstellung von Benzothiophen-Derivaten

摘要

The invention relates to a new process for the preparation of benzothiophene derivatives of the formula (I), in which R<1>, R<2>, X, m and n have the meanings given in the description. In said process the preparation of the derivatives is such that (a) firstly compounds of the formula (II) HX-R<2> are reacted with chloroacetyl chloride; (b) the resulting chloroacetic acid derivatives of the formula (IV) are subsequently reacted with thioacetic acid in the presence of a base; (c) the resulting acetylthio-aceto derivatives of the formula (VI) are thereafter reacted with ammonia in methanol, optionally acidified and reacted with benzaldehyde derivatives of the formula (VIII) in the presence of a base and optionally; (d) the resulting benzothiophene-2-carboxylic acid derivatives of the formula (IX) are finally reacted with oxidising agents.