Triphosgene → 8-bromo-3-cyclopropylquinazoline-2,4(1H,3H)-dione

Participants

Reaction Steps

Triphosgene (Sigma-Aldrich; 2.79 g, 9.41 mmol) was added to a solution of 2-amino-3-bromo-N-cyclopropylbenzamide (723a; 6.00 g, 23.52 mmol) in DCM (235 mL) at RT. The mixture was heated to reflux and stirred overnight (17 h). The mixture turned cloudy upon heating. The next morning the reaction mixture was cooled and concentrated to afford 8-bromo-3-cyclopropylquinazoline-2,4(1H,3H)-dione (723b; 6.61 g, 23.51 mmol, 100% yield) as a pale yellow solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.09 (d, J=8.02 Hz, 1H), 8.06 (br. s., 1H), 7.78 (dd, J=7.82, 1.17 Hz, 1H), 7.10 (t, J=7.92 Hz, 1H), 2.74-2.84 (m, 1H), 1.21 (q, J=7.04 Hz, 2H), 0.83-0.91 (m, 2H). m/z (ES, +ve) 281.0, 283.0 (M+H)+.

Provenance & Evidence