Patent ID: 7790891

Claim:
A process for the preparation of a compound of formula (I), or a salt thereof, either as a single isomer or as a mixture thereof, wherein Q is ═CR 8 — or ═N—; each of R 1 , R 2 , R 3 and R 4 is independently selected from hydrogen, halogen, hydroxy, nitro, C 1 -C 6 alkyl optionally substituted by hydroxy; C 1 -C 6 alkylthio; C 1 -C 6 alkoxy optionally substituted by halogen or C 1 -C 6 alkoxy; phenyl-C 1 -C 6 alkyl; phenyl-C 1 -C 6 alkoxy; and —N(R a R b ) wherein each of R a and R b is independently hydrogen or C 1 -C 6 alkyl or R a and R b , taken together with the nitrogen atom they are linked to, form a saturated heterocyclic ring; and each of R 5 , R 6 , R 7 and R 8 is independently selected from hydrogen, halogen, hydroxy; C 1 -C 6 alkyl optionally substituted by hydroxy; C 1 -C 6 alkylthio; C 1 -C 6 alkoxy optionally substituted by halogen; C 1 -C 6 alkyl-carbonyl, C 1 -C 6 alkoxy-carbonyl, and oxazol-2-yl; the process comprising the steps of: (i) providing a compound of formula (II), or a salt thereof, either as an isomeric mixture, or as an individual isomer, wherein Q and R 1 —R 7 are as defined above; and (ii) performing a reduction reaction of the compound of formula (II), or the salt thereof, either as an isomeric mixture, or as an individual isomer, with a sulfonic acid chloride, in the presence of a basic agent.