反应详情

温度

165 °C

To a round bottom flask containing polyphosphoric acid (35 g) at 165° C. was added finely ground compound 1B (3.0 g, 1.17 mmol) over 10 min. After the addition was complete, the reaction mixture was stirred for 30 min at 165° C. HPLC indicated that the reaction was complete. While at 165° C., the mixture was slowly added to a mixture of ice and sodium hydroxide. The pH was adjusted to 3.0 with additional sodium hydroxide, and the resulting mixture was filtered through a medium porosity fritted funnel to give a yellow paste which was rinsed with MeOH and DCM into a round bottom flask. The organic solvents were removed under reduced pressure and the residue was azeotripic evaporated several times with MeOH and DCM to give 2.75 g (98%) of compound 1C as a yellow solid. HPLC retention time=2.45 min. (Condition A) and LC/MS M++1=240+. 1H-NMR (500 MHz, DMSO-d6) δ 13.13 (bs, 1H), 11.96 (s, 1H), 8.31 (d, J=8.42 Hz, 1H), 8.24 (d, J=8.20 Hz, 1H), 8.18 (s, 1H), 7.77 (t, J=7.55 Hz, 1H), 7.72 (d, J=8.42 Hz, 1H), 7.55 (d, J=8.20 Hz, 1H), 7.30 (t, J=7.55 Hz, 1H).

1. additionAfter the addition
2. filtrationthe resulting mixture was filtered through a medium porosity fritted funnel
3. customto give a yellow paste which
4. washwas rinsed with MeOH and DCM into a round bottom flask
5. customThe organic solvents were removed under reduced pressure