Triphosgene → HCID 117760794, compound

Participants

Reaction Steps

A solution of 2-amino-N-(3-bromo-2-methylphenyl)-3-methylbenzamide (1.71 g, 5.36 mmol) and triphosgene (2.07 g, 6.96 mmol) in THF (20 mL) was heated at reflux for 1 h. The mixture was cooled on an ice-water bath and treated with saturated aqueous NaHCO3. Stirring was continued until gas evolution ceased. The resulting mixture was extracted 3 times with DCM. The combined organic phases were washed with water, dried and concentrated. The residue was triturated with ether to give a white solid, collected by filtration. A second trituration of the concentrated filtrate gave additional solid, collected by filtration. The filtrate from this was concentrated and purified by column chromatography on silica gel (40 g), eluting with EtOAc-hexanes (gradient from 0-100%), to provide additional solid. The three solids were combined to provide 3-(3-bromo-2-methylphenyl)-8-methylquinazoline-2,4(1H,3H)-dione as a white solid (1.69 g, 91% yield). Mass spectrum m/z 345, 347 (M+H)+. 1H NMR (400 MHz, chloroform-d): δ 8.07 (d, J=7.9 Hz, 1H), 7.70 (dd, J=7.9, 1.3 Hz, 1H), 7.54 (d, J=7.3 Hz, 1H), 7.27-7.17 (m, 3H), 2.41 (s, 3H), 2.28 (s, 3H).

Provenance & Evidence