Process for the preparation of heteroarylcarboxylic amides and esters.

摘要

The invention relates to a process for the preparation of heteroarylcarboxylic amides and esters of formula I in which A<1> through A<5>, R<1>, Hal and X one or two of the groups A<1>, A<2>, A<3>, A<4> and A<5> represent a nitrogen atom and the other groups each independently represent CR<3>, Hal represents a halogen atom, X represents oxygen or NR<2>, R1 represents an optionally substituted alkyl, aryl, heteroaryl or cycloalkyl group, R<2> represents a hydrogen atom or an alkyl group, or R<1> and R<2> together with the interjacent ring form a heterocyclic group, and R<3> each independently represent a hydrogen atom or an alkyl group, which comprises: heating a mixture consisting essentially of heteroaryltrichloromethane compound of formula II, in which A<1> through A<5> and Hal are as hereinbefore defined, and 1.0 to 1.5 equivalents of concentrated sulfuric acid, and reacting the resulting intermediate product with an alcohol or amine of formula III HXR<1> optionally in the presence of a diluent and/or a base.