反应详情

A solution of 3-(4-fluorophenyl)-propionamidine hydrochloride (Int. A108) (0.42 g, 2.05 mmol) and ethyl 2-(2,4-dioxo-4H-benzo[d][1,3]oxazin-1-yl)-acetate (0.51 g, 2.05 mmol) in pyridine (20 ml) was heated at reflux for 16 h, allowed to cool then concentrated in vacuo. The residues were chromatographed over silica eluting with ethyl acetate to yield the product as a white solid (0.26 g, 36%). 1H-NMR (CDCl3) δ 1.24 (3H, t,), 3.0 (2H, m), 3.17 (2H, m), 4.24 (2H, q), 5.29 (2H, s), 6.95 (2H, m), 7.2-7.3 (3H, m), 7.40 (1H, m), 7.67 (1H, m), 8.29 (1H, dd); MS (APCI+) found (M+1)=355; C20H19FN2O3 requires 354.

1. temperatureat reflux for 16 h
2. temperatureto cool
3. concentrationthen concentrated in vacuo
4. customThe residues were chromatographed over silica eluting with ethyl acetate