Triphosgene → 1-(2-Fluoro-4-(trifluoromethyl)benzyl)-3-(2,3-dihydro-2-oxobenzo[d]oxazol-4-yl)urea

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Reaction Conditions

Reaction Steps

Commercially available 2-fluoro-4-trifluoromethylbenzylamine (0.5 ml, 3.7 mmol) was dissolved in 20 ml of AcOEt and at 0° C. triphosgene (1.12 g, 3.7 mmol) was added to the solution. The mixture was warmed at 80° C. for 4 hours then evaporated and the residue was dissolved in 5 ml of DMF. The solution of the isocyanate was added drop wise to a solution in DMF (5 ml) of compound 1b (360 mg, 2.4 mmol) and the mixture was warmed at 80° C. for 8 hours. (TLC AcOEt). The solvent was evaporated and the crude was dissolved in AcOEt (30 ml) and washed with water (1×20 ml) and brine. The organic phase was dried over sodium sulfate and concentrated under vacuum. The purification of the crude residue by chromatographic column gave 100 mg of a white solid. Yield=11% 1HNMR (DMSO, 400 MHz) δ 4.43 (2H, d, J=6 Hz), 6.99 (3H, m), 7.05 (1H, m), 7.62 (3H, m), 8.53 (1H, bs), 10.98 (1H, bs); [M+1] 370.1 (C16H11F4N3O3 requires 369.27).

Provenance & Evidence