反应详情

温度

-78 °C

4-Chloro-5-(4-cyano-6-trifluoromethyl-pyridin-3-yl)-2-methoxy-N-methyl-N-phenyl-benzenesulfonamide (88 mg, 0.18 mmol) was dissolved in DCM (5 mL) and cooled to −78° C. A solution of BBr3 (125 mg, 0.5 mmol, 47 μL) in DCM (1 mL) was added at −78° C. and then warmed to −20° C. for 2 h. The reaction was quenched by addition of water (2 mL) and the mixture was warmed to r.t. followed by addition of EtOAc. The organic layer was separated, washed with NaHCO3 (aq) and dried (MgSO4). Purification by prep TLC eluting with 20% acetone/hexane gave 4-chloro-5-(4-cyano-6-trifluoromethyl-pyridin-3-yl)-2-hydroxy-N-methyl-N-phenyl-benzenesulfonamide contaminated with 30% of the starting material (69 mg). 35 mg of this material was dissolved in DMF (0.3 mL) and K2CO3 (14 mg, 0.1 mmol) was added followed by t-butyl-bromoacetate (20 mg, 0.1 mmol) and the mixture was stirred at r.t. for 3 days. The solvent was removed in vacuo and purification by prep TLC eluting with 20% acetone/hexane gave [5-chloro-4-(4-cyano-6-trifluoromethyl-pyridin-3-yl)-2-(methyl-phenyl-sulfamoyl)-phenoxy]-acetic acid tert-butyl ester (27 mg, 0.046 mmol). MS [M+H-tBu+H]+: 526.0; tR=3.18 min. (method 1)

1. temperaturewarmed to −20° C. for 2 h
2. customThe reaction was quenched by addition of water (2 mL)
3. temperaturethe mixture was warmed to r.t.
4. additionfollowed by addition of EtOAc
5. customThe organic layer was separated
6. washwashed with NaHCO3 (aq)
7. dry with materialdried (MgSO4)
8. customPurification by prep TLC
9. washeluting with 20% acetone/hexane