Patent ID: 8288581

Claim:
A process for the preparation of a compound selected from those of formula (IV): wherein R 1 , R 2 , R 3 and R 4 , which may be identical or different, each represent a hydrogen atom, a linear or branched (C 1 -C 6 )alkyl group, a linear or branched (C 1 -C 6 )alkoxy group, a fluorine atom, a chlorine atom, a protected amine group, a protected hydroxyl group, an alkoxycarbonyl group in which the alkoxy group is linear or branched (C 1 -C 6 ), or a CF 3 group, or R 1 and R 4 represent hydrogen and R 2 and R 3 together with the carbon atoms carrying them form a 1,3-dioxolane group, R 5 represents a saturated or unsaturated, linear or branched (C 1 -C 6 )alkyl group, a linear or branched (C 1 -C 6 )hydroxyalkyl group in which the hydroxyl function is protected, or a CO 2 R 7 group in which R 7 is a linear or branched (C 1 -C 6 )alkyl group, R 6 represents a cyano group or a CO 2 R 8 group in which R 8 is a linear or branched (C 1 -C 6 )-alkyl group, wherein a compound of formula (V) wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are as defined hereinbefore and X represents a halogen atom or a triflate group, is subjected to a cyclisation reaction in the presence of a catalyst/ligand system comprising a palladium catalyst and an organic phosphine selected from tri-tert-butylphosphine, 2-biphenyl-di-tert-butylphosphine, 1,2,3,4,5-pentaphenyl-1â€²-(di-tert-butylphosphino)-ferrocene and tris(4-methoxy-2-methylphenyl)phosphine, or a phosphonium salt of the said phosphines, in the presence of a base, in an organic solvent.