Patent ID: 7906541

Claim:
Process for the preparation of a compound of formula (III) or (III′) or a mixture thereof comprising the step of treating compound (II) with an alkoxide of formula R 2 OM where M is a sodium or a potassium cation in the corresponding alcohol of formula R 2 OH and wherein R 1 and R 2 being identical or different represent: a linear or branched C 1 -C 10 alkyl group optionally functionalized by one or more linear or cyclic C 1 -C 8 O-alkyl or S-alkyl groups, and/or O-aryl having from 6 to 10 carbon atoms optionally substituted by one or more substitutes selected from the group consisting of a halogen, NO 2 , CN, CF 3 , CCl 3 and CO 2 R i ; an arylalkyl group consisting of an aromatic ring having from 6 to 10 carbon atoms optionally substituted by one or more substitutes selected from the group consisting of linear and branched C 1 -C 10 alkyl, C 1 -C 4 alkoxy, C 6 -C 10 -aryloxy groups, OH and CO 2 R i , linked to the sulfur heteroatom or nitrogen by a C 1 -C 4 alkyl group; or A heterocyclic group, linked to the nitrogen or the sulfur heteroatom by an alkyl C 1 -C 4 chain, optionally functionalized by one or several substituents selected from the group consisting of NO 2 , CN, CF 3 , CCl 3 , a halogen, OH and CO 2 R i ; R 3 represents: a linear or branched C 1 -C 10 alkyl group optionally functionalized by C 1 -C 4 alkoxy, C 6 -C 10 -aryloxy groups or halogen; or a C 6 -C 10 aryl or heterocyclic group optionally functionalized by one or several substituents selected from the group consisting of NO 2 , CN, CF 3 , CCl 3 , a halogen, linear and branched C 1 -C 10 alkyl, C 1 -C 4 alkoxy, C 6 -C 10 -aryloxy groups, OH and CO 2 R i ; and R4, wherein R4 can occupy any of the four positions of the aromatic ring and is selected from the group consisting of hydrogen, NO 2 , CN, CF 3 , CCl 3 , a halogen, linear and branched C 1 -C 10 alkyl, C 1 -C 4 alkoxy, C 6 -C 10 -aryloxy groups, OH, and CO 2 R i or wherein R 4 consists of one to four identical or different substituants selected from the group consisting of NO 2 , CN, CF 3 , CCl 3 , a halogen, linear and branched C 1 -C 10 alkyl, C 1 -C 4 alkoxy, C 6 -C 10 -aryloxy groups, OH and CO 2 R i ; wherein R i is a C 1 -C 4 alkyl group.