反应详情

To a stirred solution of 2,5-dimethoxytetrahydrofuran (b) (1.6 mL, 12.4 mmol, 1.3 equiv) and PPTS (3.2 g, 12.4 mmol, 1.3 equiv) in 1,4-dioxane (20 mL) at 50° C., a solution of aminopyrrole (a) (1.47 g, 9.55 mmol, 1.0 eq.) in 1,4-dioxane (6 mL) was added slowly. The resulting mixture was brought to reflux and stirred for 1 h. The reaction mixture was then concentrated, dissolved in EtOAc (50 mL) and dried over anhydrous MgSO4. The crude product was purified by flash column chromatography (10% EtOAc in Hexane) to give (c) as a yellow solid (1.036 g, 53% yield). 1H NMR (400 MHz, CDCl3) δ 8.99 (s, 1H), 7.04-7.01 (m, 2H), 6.89 (t, J=3.1 Hz, 1H), 6.29 (t, J=2.9 Hz, 1H), 6.27-6.24 (m, 2H), 4.28 (q, J=7.1 Hz, 2H), 1.29 (t, J=7.1 Hz, 3H).

1. temperatureto reflux
2. concentrationThe reaction mixture was then concentrated
3. dissolutiondissolved in EtOAc (50 mL)
4. dry with materialdried over anhydrous MgSO4
5. customThe crude product was purified by flash column chromatography (10% EtOAc in Hexane)