反应详情

A solution of Example 275D (2.85 g) in 100 mL of methanol was treated with lithium carbonate (1.6 g) and PdCl2(dppf).CH2Cl2 (588 mg), heated to 120° C. under 500 psi carbon monoxide pressure for 16 hours, and concentrated. The residue was purified by silica gel column chromatography eluting with 10% ethyl acetate in n-hexane to yield 2.50 g of the desired product. MS (ESI(+)) m/e 393 (M+NH4)+; MS (ESI(−)) m/e 374 (M−H)−; 1H NMR (300 MHz, DMSO-d6) δ 9.89 (s, 1H), 7.65-7.73 (m, 2H), 7.45 (t, 1H), 7.33 (t, 1H), 7.22 (d, 1H), 6.92 (d, 1H), 6.04 (br s, 1H), 3.62 (s, 3H), 2.58-2.61 (m, 2H), 2.06 (br. 2H), 1.81 (s, 3H).

1. concentrationconcentrated
2. customThe residue was purified by silica gel column chromatography
3. washeluting with 10% ethyl acetate in n-hexane