反应详情

Triphosgene (453 mg, 1.53 mmol) was added in one portion to a solution of amino-N-(3-bromo-2-chlorophenyl)-3-fluorobenzamide (350 mg, 1.019 mmol) in THF (10 mL) at 0° C. The mixture was stirred at room temperature for 1 h, then was cooled to 0° C. and treated with water until no more gas evolution was observed. The mixture was concentrated and the residue was dissolved in EtOAc, washed sequentially with saturated aqueous NaHCO3, water and brine, and dried and concentrated. The residue was purified by column chromatography on silica gel (24 g), eluting with EtOAc-hexanes (gradient from 0-50%), to provide 3-(3-bromo-2-chlorophenyl)-8-fluoroquinazoline-2,4(1H,3H)-dione as a yellow solid (320 mg, 85% yield). Mass spectrum m/z 369, 371 (M+H)+. 1H NMR (400 MHz, chloroform-d) δ 8.54 (br. s., 1H), 7.97 (d, J=8.1 Hz, 1H), 7.77 (dd, J=6.8, 2.6 Hz, 1H), 7.46 (ddd, J=9.8, 8.3, 1.2 Hz, 1H), 7.36-7.29 (m, 2H), 7.24 (td, J=8.0, 4.8 Hz, 1H).

1. temperaturewas cooled to 0° C.
2. concentrationThe mixture was concentrated
3. dissolutionthe residue was dissolved in EtOAc
4. washwashed sequentially with saturated aqueous NaHCO3, water and brine
5. customdried
6. concentrationconcentrated
7. customThe residue was purified by column chromatography on silica gel (24 g)
8. washeluting with EtOAc-hexanes (gradient from 0-50%)