Trifluoroacetic acid → 3-(4-methoxybenzyl)-9-(methylsulfanyl)-6,7-dihydro-3H-pyrazolo[4',3':5,6]pyrido[4,3-f]quinazoline

Participants

Reaction Conditions

Reaction Steps

To a mixture of (E)-6-((dimethylamino)methylene)-2-(methylthio)-7,8-dihydroquinazolin-5(6H)-one (8 g, 32 mmol) and 1-(4-methoxybenzyl)-1H-pyrazol-5-amine (7.2 g, 35 mmol) was added trifluoroacetic acid (3 mL). The reaction mixture was heated at 100° C. for 16 hours. The reaction was cooled to room temperature and diluted with a 1:1 mixture of methanol and isopropanol (40 mL). The mixture was stirred for 30 minutes and filtered. The solid obtained was then further purified using flash column chromatography (SiO2, gradient from 100% chloroform to 2% EtOAc in chloroform) to give the desired product (3.0 g, 24%) as a yellow solid. 1H NMR (CDCl3, 400 MHz): δ 9.52 (s, 1H), 7.98 (s, 1H), 7.82 (s, 1H), 7.40 (d, J=8.0 Hz, 2H), 6.82 (d, J=8.0 Hz, 2H), 5.64 (s, 2H), 3.78 (s, 3H), 3.16 (t, J=6.0 Hz, 2H), 3.10 (t, J=6.2 Hz, 2H), 2.65 (s, 3H); LCMS [M+H]: 390.

Provenance & Evidence