HCID 57850035, compound → HCID 10014219, compound

Participants

Reaction Steps

4-hydroxy-5-nitro-3-pentyl-3,4-dihydroquinazoline (6a, 10.0 g, 38.0 mmol) was dissolved in EtOAc-MeOH mixed solvent (2:1, 150 ml) and 3% Pt—C (1.0 g) was added. Hydrogenation was carried out at room temperature under H2 atmosphere using a balloon. After 2 h, the reaction was stopped and the mixture was filtered. The filtrated was concentrated under reduced pressure and the obtaining residual oil was purified by a short silica gel (100 g) column chromatography (eluent: EtOAc/MeOH=20/1) to give 5-amino-4-hydroxy-3-pentyl-3,4-dihydroquinazoline (2a, 6.56 g, 74%); 1H NMR (270 MHz) δ (CD3OD) 0.88 (t, J=6.9 Hz, 3H), 1.23-1.41 (m, 4H), 1.63-1.74 (m, 2H), 3.26-3.35 (m, 1H), 3.51-3.62 (m, 1H), 6.15 (s, 1H), 6.47-6.51 (m, 1H), 6.55 (dd, J=1.0 and 7.9 Hz, 1H), 7.06 (t, J=7.9 Hz, 1H), 7.43 (s, 1H); MS (ES) m/z 234 (M+).

Provenance & Evidence