反应详情

温度

50 °C

Methyl ester 16 (51 mg, 0.13 mmol) was dissolved in 1 M NaOH (1:1 dioxane/H2O, 5 mL) and stirred overnight at r.t and an additional 3 h at 50° C. The reaction mixture was cooled to 0° C. and 1N HCl was added dropwise to adjust the pH to 3-4, while a white precipitate was formed. Separation of the product was accomplished by centrifugation and decanting of the supernatant. Lyophilization gave 36 mg (73%) of 17 as a beige solid. Data of 17: 1H NMR (500 MHz, DMSO-d6): δ 1.40 (s, 9H), 3.97 (s, 3H), 4.28 (s, 3H), 6.76 (s, 1H), 6.92 (s, 1H), 7.02 (d, J=8.2 Hz, 1H), 7.44 (d, J=8.2 Hz, 1H), 9.13 (s, 1H), 12.20 (brs, 1H). 13C NMR (125 MHz, DMSO-d6): δ 27.80, 36.34, 60.78, 78.29, 102.88, 104.47, 114.67, 116.12, 119.79, 123.54, 124.96, 135.00, 139.02, 145.90, 150.62, 152.78, 167.70. UV (H2O): λmax 319. MS (ESI): m/z (rel intensity) 387 (100). HRMS (FAB): calcd for C19H23N4O5, 387.1668; found, 387.1658.

1. temperatureThe reaction mixture was cooled to 0° C.
2. customwhile a white precipitate was formed
3. customSeparation of the product
4. customdecanting of the supernatant