Process for the production of carboxanilides

1. A process for the preparation of the compound of the general formula (I):

wherein R 1 is H or C 1-4 alkyl and R 2 is difluoromethyl or trifluoromethyl, which comprises reacting the compound of the general formula (II):

wherein R 1 has the meaning given above and X is chloro or bromo, with a compound of the general formula (III):

wherein R 2 has the meaning given above, in the presence of a base, a palladium catalyst and a ferrocenyl biphoshine ligand of the Josiphos type, the reaction being carried out in an ether solvent at a reflux temperature of at least 100° C.

2. A process according to claim 1 wherein X is chloro.

3. A process according to claim 1 wherein the base is a hydroxide or carbonate of sodium, potassium, cesium, lithium, calcium or barium, the phosphates of sodium or potassium or the C 1 -C 4 alkoxide of sodium or potassium.

4. A process according to claim 1 wherein the palladium catalyst is palladium dichloride, palladium(II) acetate, tris-dibenzylideneacetone-dipalladium or bis-dibenzylideneacetone palladium.

5. A process according to claim 1 wherein the ligand is (R)-(−)-1-[(S)-2-(dicyclohexylphosphino)-ferrocenyl]ethyldi-tert-butylphosphine having the structural formula:

6. A process according to claim 1 wherein the solvent is diethyleneglycol dialkylethers having the general formula:

ROCH 2 CH 2 OCH 2 CH 2 OR

wherein R is C 1-4 alkyl.

7. A process according to claim 5 wherein the solvent is di(ethylene glycol) dimethyl ether.

8. A process according to claim 1 wherein the reaction is carried out at a temperature of from 130 to 200° C.