Process for the preparation of arylamides of heteroaromatic carboxylic acids

The invention relates to a process for the preparation of arylamides of heteroaromatic carboxylic acids by the reaction of heteroaromatic halogen compounds with carbon monoxide and aromatic amines in the presence of a catalyst and a base. It further relates to a process for the preparation of arylamides of heteroaromatic carboxylic acids which carry an aryloxy or heteroaryloxy group as a substituent on the heteroaromatic ring, by the reaction of heteroaromatic dihalogen compounds with aromatic or heteroaromatic hydroxyl compounds to give (hetero)aryloxy-substituted heteroaromatic monohalogen compounds, and the further reaction of these compounds with carbon monoxide and aromatic amines in the presence of a catalyst and a base. A process for the preparation of arylamides of heteroaromatic carboxylic acids of the formula: in which each Ais nitrogen or CR(n=1 to 5), with the proviso that at least one of the ring members is nitrogen and that two nitrogen atoms are not bonded directly to one another; Rto R, if present, independently of one another; C-alkyl or aryl, one of the substituents Rto Rbeing a group of the formula -OR, in which R is an optionally substituted aromatic or heteroaromatic radical; Ris hydrogen or C-alkyl; and Ris an optionally substituted aromatic or heteroaromatic radical. The amides are obtained from the corresponding heteroaromatic halogen compounds, the corresponding aromatic amines and carbon monoxide in the presence of palladium diphosphine complex. Compounds of this class (Formula I) are important herbicides.