反应详情

N-(2-Bromo-5-chloro-pyridin-3-yl)-4-tert-butyl-N-methoxymethyl-benzenesulfonamide (140 mg, 300 mmol) was placed in a dry 2-neck 10 mL round-bottom flask. The flask was evacuated and purged with nitrogen, followed by the addition of THF (1 mL). The homogeneous mixture was lowered to −5° C. and iPrMgCl (0.33 mL, 2.0 M) was added dropwise. Upon completion of the addition, the reaction was stirred 90 minutes, followed by the slow addition of 2-fluoro-N-methoxy-N-methyl-benzamide (140 mg, 750 mmol). The reaction was stirred overnight, during which the ice-bath warmed to room temperature. The following day, the reaction was quenched with a small quantity of MeOH and the solvents evaporated in vacuo. The residue was subsequently treated with 4.0 M HCl (in dioxane) (1 mL, 4.0 mmol) and H2O (0.33 mL), and then stirred at 80° C. for two hours. The resultant solution was diluted with EtOAc, washed with water, saturated sodium bicarbonate, and brine; dried with MgSO4, and evaporated employing reduced pressure. The crude sulfonamide was finally purified via preparatory TLC (20% EtOAc/hexanes) and recrystallization from MeCN/H2O to afford 98 mg of the title compound: 1H NMR (400 MHz, CDCl3) δ 10.6 (s, 1H), 8.3 (d, 1H), 8.2 (d, 1H), 7.74 (d, 2H), 7.6 (d, 1H), 7.5 (d, 1H), 7.43 (d, 2H), 7.42-7.37 (m, 2H), 1.26 (s, 9H); MS (ES) M+H expect 447.1, found 447.5.

1. customThe flask was evacuated
2. custompurged with nitrogen
3. additionfollowed by the addition of THF (1 mL)
4. customwas lowered to −5° C.
5. additioniPrMgCl (0.33 mL, 2.0 M) was added dropwise
6. additionUpon completion of the addition
7. customThe following day, the reaction was quenched with a small quantity of MeOH
8. customthe solvents evaporated in vacuo
9. stirringstirred at 80° C. for two hours
10. washwashed with water, saturated sodium bicarbonate, and brine
11. dry with materialdried with MgSO4
12. customevaporated
13. customThe crude sulfonamide was finally purified via preparatory TLC (20% EtOAc/hexanes) and recrystallization from MeCN/H2O