Methyl iodide → (7-Chloro-3,6-dimethyl-4-oxo-3,4-dihydroquinazolin-2-yl)methyl acetate

Participants

Reaction Steps

To a suspension of 2-acetoxymethyl-7-chloro-6-methyl-3,4-dihydroquinazolin-4-one 0.428 g, 1.6 mmol) in anhydrous DMF (13 ml) was added sodium hydride (60% dispersion, 0.070 g, 1.76 mmol) under argon. Stirring was continued at room temperature for 1 min and then iodomethane (0.20 ml, 3.2 mmol) was added into the reaction mixture with a syringe via a septum. Stirring was continued at room temperature for 1 hour and the reaction mixture was then partitioned between ethyl acetate (130 ml) and brine (80 ml). The organic layer was washed with dilute brine (80 ml), dried (Na2SO4) and concentrated in vacuo to leave an orange residue. This orange residue was dissolved in dichloromethane and to this solution silica gel (Art 7734, 1.7 g) was added. The solvent was removed in vacuo and the orange free running powder was placed on a silica gel column made up in 5% ethyl acetate in dichloromethane. The column was eluted with 5% ethyl acetate in dichloromethane to afford a pale yellow solid (0.300 g, 67%), mp 110-112° C.; 1H-NMR (DMSO-d6) 2.17 (s, 3H, CH3CO), 2.47 (s, 3H, 6-CH3), 3.54 (s, 3H, N3—CH3), 5.23 (s, 2H, 2-CH2O), 7.71, 8.09 (2×s, 2H, 5-H, 8-H).

Provenance & Evidence