反应详情

3-Methyl-4-(4-methylthiazol-2-yl)benzoic acid (all recovered product from step A above) was dissolved in acetic acid (20 mL, 349 mmol), and bromine (1.774 mL, 34.4 mmol) was added. After sonicating for 5 minutes, LCMS showed complete conversion. Excess sodium bisulfite was added to the reaction solution until the red color disappeared. The suspension was filtered, and the filtrate was concentrated. The crude was purified on a silica gel column, eluting with 30% ethyl acetate, to give title compound as a white solid (6.2 g, 87% yield). LCMS (M+H)+: 313.9. 1H NMR (DMSO, 500 MHz): δ 7.90 (s, 1H), 7.85 (s, 2H), 2.56 (s, 3H), 2.40 (s, 3H).

1. customAfter sonicating for 5 minutes
2. filtrationThe suspension was filtered
3. concentrationthe filtrate was concentrated
4. customThe crude was purified on a silica gel column
5. washeluting with 30% ethyl acetate