反应详情

The product of Example 451C (0.23 g, 0.4 mmo) in CH2Cl2 (4.6 mL) was treated with trifluoroacetic acid [TFA] (1.15 mL) dropwise at room temperature then stirred for 1 hour. The reaction mixture was concentrated. The residue was diluted with water, made basic with K2CO3, stirred at room temperature overnight. The pH was adjusted to pH 5-6 with 1N HCl stirred at room temperature for 1 hour, the resulting precipitate was collected by filtration, washed with water and i-Pr2O, and dried at 40° C. in vacuum overnight to give the title compound as yellow crystal (0.13 g, 71%). 1H-NMR (300 MHz, DMSO-d6) δ ppm: 1.34 (d, J=7.0 Hz, 6H), 3.42-3.60 (m, 1H), 5.64 (br-s, 2H), 6.64 (d, J=8.4 Hz, 2H), 6.84 (d, J=7.7 Hz, 1H), 7.14 (d, J=8.4 Hz, 2H), 7.73 (br-d, J=7.7 Hz, 1H), 7.83 (br-s, 1H), 8.58 (s, 1H), 8.65-8.80 (m, 1H), 10.10 (s, 1H), 12.91 (br-s, 1H). MS ESI+m/z: 450 (M+H), ESI− m/z: 448 (M−H).

1. concentrationThe reaction mixture was concentrated
2. additionThe residue was diluted with water
3. stirringstirred at room temperature overnight
4. stirringstirred at room temperature for 1 hour
5. filtrationthe resulting precipitate was collected by filtration
6. washwashed with water and i-Pr2O
7. customdried at 40° C. in vacuum overnight