Dimethylformamide dimethyl acetal → (E)-6-((dimethylamino)methylene)-2-(methylthio)-7,8-dihydroquinazolin-5(6H)-one

Participants

Reaction Steps

To a solution of 2-(methylthio)-7,8-dihydroquinazolin-5(6H)-one (0.2 g, 1.0 mmol) in toluene (3 mL) was added DMFDMA (0.2 mL, 1.5 mmol). The reaction mixture was then refluxed for 16 hours. The reaction mixture was then cooled to room temperature and concentrated under reduced pressure. The crude compound was purified by flash column chromatography (SiO2, gradient from 100% dichloromethane to 2% methanol in dichloromethane) to give the pure desired product (0.15 g, 60%) as a solid. 1H NMR (CDCl3, 400 MHz): δ 9.0 (s, 1H), 7.72 (s, 1H), 3.18 (s, 6H), 2.98 (t, J=6.0 Hz, 2H), 2.92 (t, J=6.0 Hz, 2H), 2.60 (s, 3H); LCMS [M+H]: 250.

Provenance & Evidence