Alpha-keto-acid and ester prepn. - by reacting (alkyl)oxalyl halide with hetero:aromatic cpd.

摘要

Alpha-beta-acids of formula (II) are prepd. by reacting a heteroaromatic cpd. of formula (I) with an oxalyl halide at 20-100 deg.C. Also claimed is the prepn. of alpha-beta-esters of formula (III) by reacting (I) with alkyl oxalyl halide at 20-120 deg.C Pref. Y is S, Se, O or N-R" (R" is alkyl or aryl) and R3, R4 and R5 are H, alky, aryl and/or halogen, provided that one alpha position of the heterocycle is free from substitution. The prods. are obtd. in good yields.