Patent ID: 7321061

Claim:
A process for preparing a compound of Formula I: Ar—R—SO 2 —X I wherein: Ar is aryl or heteroaryl optionally substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, heterocycloalkyl, formyl, cyano, nitro, OH, C 1 -C 6 alkoxy, arylalkyloxy, C 1 -C 6 haloalkyl, C 1 -C 3 perhaloalkyl, C 1 -C 6 haloalkoxy, C 1 -C 3 perhaloalkoxy, NR 1 R 2 , NR 1 COR 3 , aryl, aryloxy, heteroaryl and heteroaryloxy; R is C 1 -C 6 alkylenyl; R 1 and R 2 are each independently selected from the group consisting of H, C 1 -C 6 alkyl and C 3 -C 7 cycloalkyl; or R 1 and R 2 together with the N atom to which they are attached form a 5- or 6-membered heterocycle; R 3 is selected from the group consisting of H, C 1 -C 6 alkyl and C 3 -C 7 cycloalkyl; and X is halogen; comprising: (a) reacting a compound of Formula II: Ar—R-L II wherein L is a leaving group, with a Group I or II metal sulfite salt optionally in the presence of a phase transfer catalyst to form a sulfonic acid salt compound of Formula III: (Ar—R—SO 3 −1 ) q M III wherein M is a Group I or II metal ion; wherein q is 1 where M is Group I metal ion, and q is 2 where M is a Group II metal ion; (b) reacting said compound of Formula III with a protic acid to form a sulfonic acid compound of Formula IV: Ar—R—SO 3 H IV and (c) reacting said compound of Formula IV with a halogen substitution reagent to form said compound of Formula I.