反应详情

Ethyl 7-ethyl-4-oxo-1,4-dihydropyrrolo[1,2-a]pyrimidine-3-carboxylate (0.63 g, 2.711 mmol) was dissolved in a solution of methanol (8 mL)/sodium hydroxide (13.56 mL, 2.0 M, 27.11 mmol) and heated at reflux for 3 hours. The mixture was allowed to cool to room temperature and methanol was removed in vacuo. The aqueous solution was cooled to 0° C. and concentrated HCl was slowly added until a precipitate formed (pH 4). The precipitate was filtered, washed with water and dried to give 7-ethyl-4-oxo-1,4-dihydropyrrolo[1,2-a]pyrimidine-3-carboxylic acid; 0.43 g (77%). LC/MS (10-99% CH3CN/0.05% TFA in H2O/0.05% TFA gradient over 3 min): M+H m/z 207.1, retention time 1.10 minutes. 1H NMR (400.0 MHz, DMSO) δ 13.42 (bs, 1H), 12.89 (bs, 1H), 8.51 (s, 1H), 7.29 (t, J=0.8 Hz, 1H), 6.17 (d, J=1.8 Hz, 1H), 2.61-2.50 (m, 2H) and 1.20 (t, J=7.5 Hz, 3H).

1. temperatureheated
2. temperatureat reflux for 3 hours
3. custommethanol was removed in vacuo
4. temperatureThe aqueous solution was cooled to 0° C.
5. additionconcentrated HCl was slowly added until a precipitate
6. customformed (pH 4)
7. filtrationThe precipitate was filtered
8. washwashed with water
9. customdried