反应详情

To a solution of 2,5-dichlorobenzenesulphonyl chloride (52 mg, 0.21 mmol) in dichloromethane (1.5 mL) was added pyridine (40 μL, 0.5 mmol) and the mixture was stirred under N2 for 5 min, after which time 5-amino-2-methylbenzoxazole (30 mg, 0.20 mmol) was added. The resulting mixture was stirred for 1 h at room temperature, then saturated NaHCO3 solution was added (8 mL) and the mixture was extracted into ethyl acetate (15 mL). The organic phase was washed with brine, dried (Na2SO4), filtered and evaporated to give a residue that was purified using flash chromatography to afford a pale pink solid (45 mg, 63%), single spot at Rf 0.53 (1:1 hexane:ethyl acetate). mp 193.5-193.9° C., HPLC purity 98% (tR 2.27 min in 10% water-acetonitrile). 1H NMR (CDCl3): δ 7.86 (1H, d, J=2.2 Hz), 7.39 (4H, m), 7.12 (1H, dd, J=8.4, 1.8 Hz), 2.58 (3H, s). LCMS: 355.07 (M−). FAB-MS (MH+, C14H10Cl2N2O3S): calcd 356.9867, found 356.9878.

1. stirringThe resulting mixture was stirred for 1 h at room temperature
2. extractionthe mixture was extracted into ethyl acetate (15 mL)
3. washThe organic phase was washed with brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. customevaporated
7. customto give a residue that
8. customwas purified