反应详情

Aqueous formaldehyde (15.0 g of 38% solution, 190 mmol) was added to a stirred solution of 3-(3,5-dimethyl-1H-pyrrol-2-ylmethylidene)-1,3-dihydro-indol-2-one (23.8 g, 100 mmol) and triethylamine (15.0 g, 150 mmol) in dimethylformamide (200 mL). After 1 h, the solution was diluted with water and the precipitate was filtered off, washed with water, and dried to give 26.4 g of the title compound, mp 196-200° C. HPLC Rt 5.71 min. 1H NMR (CDCl3) δ2.34 (s, 6H), 3.14 (t, 1H), 5.44 (d, 2H), 5.98 (d, 1H), 7.08 (m, 2H), 7.18 (m, 1H), 7.36 (s, 1H), 7.48 (dd, 1H) and 13.0 (br s, 1H). Anal. Calcd for C16H16N2O2: C, 71.62; H, 6.01; N, 10.44. Found: C, 71.33; H, 6.09; N, 10.43. A sample was recrystallized from ethyl acetate; mp 200-202° C.

1. filtrationthe precipitate was filtered off
2. washwashed with water
3. customdried