4-Chlorobenzylamine → 1-(4-chlorobenzyl)-3-(3,4-dihydro-3-oxo-2H-benzo[b][1,4]oxazin-8-yl)urea

Participants

Reaction Conditions

Reaction Steps

Commercially available p-chlorobenzylamine (0.98 ml, 8 mmol) was dissolved in 40 ml of AcOEt and at 0° C. triphosgene (2.37 g, 1 equiv.) was added to the solution. The mixture was warmed at 80° C. for 4 hours then evaporated and the residue was dissolved in 20 ml of DMF. The solution of the isocyanate was added dropwise to a solution in DMF (10 ml) of compound 1f (1.42 g, 7.11 mmol) and the mixture was warmed at 80° C. for 8 hours. (TLC AcOEt 1/petroleum ether 1). The solvent was evaporated and to the crude 5% HCl was added. The solid was filtrated, washed with water, MeOH and diethyl ether obtaining 1.6 g of a white product. Yield=68% 1HNMR (DMSO, 200 MHz) δ 4.27 (2H, d, J=5.6 Hz), 4.61 (2H, s), 6.47 (1H, dd, J=7.8 Hz, J′=1.2 Hz), 6.81 (1H, t, J=8.2 Hz), 7.35 (5H, m), 7.73 (1H, dd, J=8.2 Hz, J′=1.2 Hz), 8.10 (1H, bs), 10.65 (1H, bs); [M+1] 332.4 (C16H14ClN3O3 requires 331.75).

Provenance & Evidence