反应详情

The product from Step A (2.0 g, 6.6 mmol) was dissolved in a 30% solution of hydrobromic acid/acetic acid (18.0 mL). This mixture was stirred at room temperature for four days. The mixture was poured into aqueous 1M sodium carbonate (150 mL) and then extracted with ethyl acetate (5×50 mL). The combined extracts were dried (MgSO4) and then evaporated. The solid residue was recrystallized from hexane to afford 1.0 g (45%) of the title compound melting at 74°-76° C. 1H NMR (400 MHz, CDCl3) δ 10.64 (br s, 1H), 8.92 (s, 1H), 8.66 (s, 1H), 8.38 (m, 1H), 729-7.43 (s, 1H), 7.29-7.32 (m, 1H), 2.39 (s, 3H), 1.33 (s, 9H). Mass spec (EI) m/e 349 (1XBr).

1. extractionextracted with ethyl acetate (5×50 mL)
2. dry with materialThe combined extracts were dried (MgSO4)
3. customevaporated
4. customThe solid residue was recrystallized from hexane