| abstract |
Described is a process for the preparation of amides and esters of heteroarylcarboxylic acids of formula (I), in which the general radicals A1 to A5, R1, Hal and X have the following meanings: one of the groups A1, A2, A3, A4 and A5 represents a nitrogen atom and the remaining groups independently CH, Hal represents a halogen atom, X represents O or NR 2, R 1 represents a C 1-6 -alkyl group, a phenyl group, a pyridimidine group or a C 3-8 -cycloalkyl group which may be substituted by one or more halogen atoms, nitro groups, cyano groups, C1-6-alkyl groups, C1-6-alkoxy groups or C1-10-haloalkyl groups; R 2 represents a hydrogen atom or a C 1-10 -alkyl group, or R 1 and R 2 together with the intermediate ring form a heterocyclic group having 5 to 8 ring atoms. |