反应详情

A stirred mixture of 5-hydroxy-2H-benzo[b][1,4]oxazin-3(4H)-one (100 mg, 0.604 mmol) and K2CO3 (167 mg, 1.21 mmol) in anhydrous DMF (5 mL) was treated with ethyl 2-bromoacetate (121 mg, 0.727 mmol) and stirring continued at room temperature for 16 h. To this solution of crude ethyl 2-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-5-yloxy)acetate was added K2CO3 (39.6 mg, 0.287 mmol) followed by MeI (40.7 mg, 0.287 mmol). After being stirred at room temperature for 16 h, the reaction mixture was partitioned between water (50 mL) and DCM (100 mL). The organic layer was washed by water followed by and brine, dried over anhydrous Na2SO4, filtered and concentrated and the resulting residue was purified by preparative TLC to give desired product (43 mg, 56% yield). 1H NMR (400 MHz, CDCl3): 6.99 (t, J=8.3 Hz, 1H), 6.74 (d, J=7.5 Hz, 1H), 6.55 (d, J=8.3 Hz, 1H), 4.69 (s, 2H), 4.51 (s, 2H), 4.30 (q, J=7.2 Hz, 2H), 3.56 (s, 3H), 1.34-1.33 (m, 1H), 1.33 (t, J=7.2 Hz, 3H)

1. stirringAfter being stirred at room temperature for 16 h
2. customthe reaction mixture was partitioned between water (50 mL) and DCM (100 mL)
3. washThe organic layer was washed by water
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customthe resulting residue was purified by preparative TLC