Chlorosulfonic acid → 4-Chloro-5-(4-cyano-6-trifluoromethyl-pyridin-3-yl)-2-methoxy-benzenesulfonyl chloride
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[CH:4][C:3]=1[C:10]1[C:15]([C:16]#[N:17])=[CH:14][C:13]([C:18]([F:21])([F:20])[F:19])=[N:12][CH:11]=1.[Cl:22][S:23](O)(=[O:25])=[O:24]>C(Cl)(Cl)Cl>[Cl:1][C:2]1[C:3]([C:10]2[CH:11]=[N:12][C:13]([C:18]([F:21])([F:19])[F:20])=[CH:14][C:15]=2[C:16]#[N:17])=[CH:4][C:5]([S:23]([Cl:22])(=[O:25])=[O:24])=[C:6]([O:8][CH3:9])[CH:7]=1Participants
4
Procedure
To 5-(2-chloro-4-methoxy-phenyl)-2-trifluoromethylisonicotinonitrile (0.7 g, 2.24 mmol) in chloroform (6 mL), was added to ClSO3H (0.62 mL). The solution was stirred at rt for 16 hrs. The solvent was removed and MeCN (3 mL) was added, followed by addition of POCl3 (3 mL). The mixture was heated at 60° C. for 16 hrs, then concentrated. The remainder was poured into ice water with stirring. The resulting solid was filtered, dried in vacuo over 2 days to yield 4-chloro-5-(4-cyano-6-trifluoromethyl-pyridin-3-yl)-2-methoxy-benzenesulfonyl chloride (0.79 g) as a pale yellow solid. tR=2.92 min (method 1).