Pyridine → Phenol, 3-chloro-5-methoxy-, 1-methanesulfonate

Reaction equation

[CH3:1][O:2][C:3]1[CH:4]=[C:5]([O:18][S:19]([CH3:22])(=[O:21])=[O:20])[CH:6]=[C:7](B2OC(C)(C)C(C)(C)O2)[CH:8]=1.N1C=CC=CC=1.CS([Cl:33])(=O)=O>ClCCl>[Cl:33][C:7]1[CH:6]=[C:5]([O:18][S:19]([CH3:22])(=[O:21])=[O:20])[CH:4]=[C:3]([O:2][CH3:1])[CH:8]=1

Participants

Procedure

To a 0° C. solution of 3-chloro-5-methoxy-phenol (Scheme #4, K) (16.62 g, 104.80 mmol) and pyridine (12.8 mL, 157.20 mmol) in dichloromethane (150 mL) was added methanesulfonyl chloride (8.9 mL, 115.28 mmol). The reaction was warmed to room temperature and stirred 24 hours. The dichloromethane was removed under reduced pressure and the crude material partitioned between ethyl acetate and 1N hydrochloric acid. The organic layer was washed 1N hydrochloric acid (4×), aqueous saturated sodium chloride (1×), saturated potassium carbonate (3×), aqueous saturated sodium chloride (1×), dried over magnesium sulfate, and solvent removed under reduced pressure. The crude solid was crystallized overnight from dichloromethane (50 mL) and crystals filtered off, washed with dichloromethane, and placed under high vacuum to give the title compound (9.35 g, 38%). 1H NMR (300 MHz, DMSO-d6) δ 7.09 (t, J=2.0 Hz, 1 H), 7.05 (t, J=1.9 Hz, 1 H), 6.93 (t, J=2.1 Hz, 1 H), 3.82 (s, 3 H), 3.42 (s, 3 H); MS (APCI+) m/z 237 [M+1]+; tR=2.28 min.