反应详情

tert-Butyl bromoacetate (1.34 mL, 9.1 mmol) was added to a solution of 7-bromo-2H-3,1-benzoxazine-2,4(1H)-dione from Step B (2 g, 8.26 mmol) and potassium carbonate (1.3 mg, 9.1 mmol) in DMF (20 mL) and stirred at ambient temperature for 4 h. 1 N NaOH (15 mL) was then added to the reaction and after 1 h, the mixture was partitioned between 0.5 N HCl and EtOAc. The organic layer was dried over Na2SO4, filtered, and concentrated to give the title compound in sufficient purity for use in the next step. MS: m/z=275 (M+1-tert-butyl).

1. customthe mixture was partitioned between 0.5 N HCl and EtOAc
2. dry with materialThe organic layer was dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated