4-Chlorophenyl Isocyanate → 1-(4-chloro-phenyl)-3-(4-oxo-4H-chromen-6-yl)-urea

Participants

Reaction Steps

To the slurry of 6-aminochromone (3.0 g, 18.6 mmol) stirred and heated to 80° C. in toluene (200 mL) was added 4-chlorophenyl isocyanate (3.2 g, 20.5 mmol) and the mixture was refluxed for 18 hrs. The reaction mixture was cooled and the precipitate was filtered and washed with methanol. The residue was dried in vacuo to afford a yellow powder (5.8 g, 99%) of 1-(4-chloro-phenyl)-3-(4-oxo-4H-chromen-6-yl)-urea. LCMS m/z (%)=315 (M+H, 35Cl 100), 317 (M+H, 37Cl 32.2) 1H NMR (400 MHz, DMSO-d6) δ: 9.098 (bs, 1H), 8.94 (bs, 1H), 8.28-8.30 (d, J=5.99 Hz, 1H), 8.20-8.21 (d, J=2.69 Hz, 1H), 7.81-7.84 (dd, J=9.0, 2.75 Hz, 1H), 7.62-7.64 (d, J=9.07 Hz, 1H), 7.52-7.55 (dd, J=6.84, 2.16 Hz, 2H), 7.35-7.37 (dd, J=6.85, 2.11 Hz, 2H), 6.33-6.34 (d, J=5.98 Hz, 1H).

Provenance & Evidence