反应详情

4-(4-tert-Butylthiazol-2-yl)-3-methylbenzoic acid (Step B, 7.0 g, 25.4 mmol) was dissolved in 30 mL of acetic acid, and bromine (8.1 g, 50.8 mmol) was added. The red mixture was stirred at room temperature for 20 minutes to see complete conversion by LCMS. Excess sodium bisulfite was added until the reaction mixture became colorless. The mixture was concentrated to dryness, dry-loaded to a silica gel column, and purified, eluting with 10% methanol in methylene chloride, to get 4-(5-bromo-4-tert-butylthiazol-2-yl)-3-methylbenzoic acid as a white solid (8.5 g, 94% yield over 2 steps). LCMS (M+H)+: 355.9; 353.9. 1H NMR (CDCl3, 500 MHz): 7.92 (s, 1H), 7.84 (m, 2H), 2.60 (s, 3H), 1.49 (s, 9H).

1. concentrationThe mixture was concentrated to dryness, dry-loaded to a silica gel column
2. custompurified
3. washeluting with 10% methanol in methylene chloride