Methyl iodide → 8-iodo-3-methyl-2-(methylthio)quinazolin-4(3H)-one

Participants

Reaction Steps

At RT, to a mixture of 8-iodo-3-methyl-2-thioxo-2,3-dihydroquinazolin-4(1H)-one (11.2 g g, 35.3 mmol) and K2CO3 (9.76 g, 70.6 mmol) in THF (100 mL) was added MeI (6.58 mL, 106 mmol). The reaction was heated to reflux for 6 h, and then cooled to RT. The mixture was poured into ice/water (300 mL) and stirred for 10 min. The suspension was filtered and the solid was washed with cold water (20 mL) followed by cold ether (20 mL). The solid was dried to give 8-iodo-3-methyl-2-(methylthio)quinazolin-4(3H)-one (700a; 11.4 g, 97% yield) as an off-white solid. Crude material was used in the next step. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.31 (1H, dd, J=7.6, 1.4 Hz), 8.08 (1H, dd, J=7.8, 1.4 Hz), 7.19 (1H, t, J=7.7 Hz), 3.51 (3H, s), 2.73 (3H, s). m/z (ES, +ve) 332.9 (M+H)+.

Provenance & Evidence