Dimethyl Sulfate → tert-butyl (2R)-2-{[(3-{[(2,2-dimethylpropanoyl)oxy]methyl}-7-methoxy-4-oxo-3,4-dihydroquinazolin-5-yl)oxy]methyl}pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Potassium carbonate (1.60 g, 12.6 mmol) was added to a solution of tert-butyl (2R)-2-{[(3-{[(2,2-dimethylpropanoyl)oxy]methyl}-7-hydroxy-4-oxo-3,4-dihydroquinazolin-5-yl)oxy]methyl}pyrrolidine-1-carboxylate (1.50 g, 3.2 mmol) in dimethylformamide (10 ml) and the mixture stirred at 0° C. for 5 minutes. Dimethyl sulphate (0.6 ml, 6.3 mmol) was added and the reaction stirred at 0° C. for a further 5 minutes and then warmed to room temperature and stirred for 1 hour. The reaction mixture was evaporated under reduced pressure and the residue dissolved in dichloromethane (20 ml) and washed with water (2×20 ml). The organics were dried over magnesium sulphate, filtered and evaporated under reduced pressure to give tert-butyl (2R)-2-{[(3-{[(2,2-dimethylpropanoyl)oxy]methyl}-7-methoxy-4-oxo-3,4-dihydroquinazolin-5-yl)oxy]methyl}pyrrolidine-1-carboxylate (0.750 g, 48% yield) which was used in the next stage without further purification.

Provenance & Evidence