Patent ID: 8110701

Claim:
A process for the preparation of a compound selected from those of formula (VIIa): 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, and R 10 represents a hydrogen atom or a linear or branched (C 1 -C 6 )alkyl group, wherein a compound of formula (Va): wherein R 1 , R 2 , R 3 , R 4 , are as defined hereinbefore, R 7 represents a linear or branched (C 1 -C 6 )alkyl group, R 8 represents a linear or branched (C 1 -C 6 )alkyl group, and X represents a halogen atom, is converted into a compound of formula (IVa): wherein R 1 , R 2 , R 3 , R 4 , R 7 and R 8 are as defined hereinbefore, via 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-1′-(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, and then the compound of formula (IVa) is converted into a compound of formula (VIa): wherein R 1 , R 2 , R 3 and R 4 are as defined hereinbefore and R 9 is a linear or branched (C 1 -C 6 )alkyl group, by an ester saponification or hydrolysis reaction, and the compound of formula (VIa) is subjected to a decarboxylation reaction to yield the compound of formula (VIIa).