Water → 8-bromo-7-fluoro-3-methylquinazoline-2,4(1H,3H)-dione

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Reaction Steps

A mixture of tri-phosgene (Aldrich, St. Louis, Mo.; 0.233 g, 0.784 mmol) and 2-amino-3-bromo-4-fluoro-N-methylbenzamide (720a; 0.57 g, 2.30 mmol) in 23 mL anhydrous DCM was fitted with a water-cooled reflux condenser and drying tube, and heated to reflux overnight. LCMS indicated the reaction was about 85% conversion. Additional triphosgene (0.075 g) was added and heating continued for 5 h. The reaction was cooled and concentrated in vacuo to give 8-bromo-7-fluoro-3-methylquinazoline-2,4(1H,3H)-dione (0.63 g, 2.30 mmol, 100% yield) as a light orange solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.89 (1H, s), 8.03 (1H, dd, J=8.8, 5.9 Hz), 7.23 (1H, t, J=8.6 Hz), 3.26 (3H, s). MS (ESI, pos. ion) m/z: 272.9/275.0 (M+1).

Provenance & Evidence