Formaldehyde → HCID 178424865, compound

Participants

Reaction Steps

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) δ 2.34 (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.

Provenance & Evidence