Patent ID: 7297799

Claim:
A process for the preparation of a compound of formula (I′): or a salt or quaternary ammonium salt thereof wherein R′ 1 is halogen, CF 3 , (C 1 -C 4 ) alkyl or (C 1 -C 4 ) alkoxy; R′ 2 is (C 1 -C 6 ) alkyl, (C 3 -C 7 ) cycloalkyl, (C 1 -C 6 ) alkoxy; halogen, CF 3 , hydroxy, a group selected from phenyl, phenoxy, phenylmethyl or phenylethyl, said group being optionally mono- or polysubstituted on the phenyl by halogen, CF 3 , (C 1 -C 4 ) alkyl or (C 1 -C 4 ) alkoxy; R′ 3 is hydrogen, (C 1 -C 6 ) alkyl, (C 1 -C 6 ) alkoxy, halogen, CF 3 or hydroxy; comprising: (a) reacting an aryl-1,2,3,6-tetrahydropyridine of formula (II) with a compound of formula (III) in which R′ 1 , R′ 2 and R′ 3 are as defined above and L is a leaving group selected from chlorine, bromine, iodine, methanesulfonyloxy, benzenesulfonyloxy, p-tolunesulfonyloxy or trifluoromethanesulfonyloxy; and (b) converting the compound of formula (I′) thus obtained into quaternary ammonium salts by reacting with an alkyl halide of formula (IV): Alk-Hal (IV) wherein Alk is (C 1 -C 4 ) alkyl and Hal is chlorine, bromine or iodine.