反应详情

The product from Example 35 (180 mg, 0.32 mmol) in 1,2-dichloroethane (2.0 mL) was treated with 2-methylpropanal (36 μl, 0.38 mmol) at ambient temperature. After stirring for 15 minutes, the mixture was treated with acetic acid (22 μl, 0.38 mmol) and sodium triacetoxyborohydride (108 mg, 0.51 mmol) at ambient temperature. After stirring for 2 hours, the mixture was treated with aqueous 10% sodium bicarbonate (2.0 mL) and extracted with ethyl acetate (3×5 mL). The ethyl acetate extracts were combined, washed with brine (5 mL), dried over sodium sulfate, filtered, and the filtrate was concentrated. The residue was purified by column chromatography on silica gel eluting with (chloroform:methanol, 99:1) to provide the title compound (155 mg, 78%). 1H NMR (CDCl3) δ 8.73 (s, 2H), 7.75 (s, 2H), 7.31-7.11 (m, 10H), 5.33 (br s, 2H), 5.18 (q, 4H), 3.96 (br s, 2H), 2.83 (m, 2H), 2.71 (dd, 2H), 2.42 (t, 2H), 2.21 (dd, 2H), 2.05-1.83 (m, 2H), 1.46 (m, 1H), 0.72 (dd, 6H); MS (ESI+) m/z 622 (M+H)+.

1. stirringAfter stirring for 2 hours
2. extractionextracted with ethyl acetate (3×5 mL)
3. washwashed with brine (5 mL)
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationthe filtrate was concentrated
7. customThe residue was purified by column chromatography on silica gel eluting with (chloroform:methanol, 99:1)