4H-1,4-benzoxazin-3-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2H-1,4-benzoxazin-3-(4H)-one (1.6 g, 10.7 mmol), 4-(2-bromoethoxy)benzaldehyde (2.95 g, 12.8 mmol) and potassium carbonate (5.93 g, 42.97 mmol) in dry dimethyl formamide (30 mL) was stirred at 80° C. for 10 h. Water (100 mL) was added and extracted with ethyl acetate (2×75 mL). The combined organic layers were washed with water (50 mL), brine (50 mL), dried (Na2SO4), filtered and the solvent was evaporated. The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2: 8) to afford the title compound (2.9 g, 91%) as a colorless solid. mp : 75-78° C. extracted with ethyl acetate (2×75 mL) The combined organic layers were washed with water (50 mL), brine (50 mL) dried (Na2SO4) filtered the solvent was evaporated The residue was chromatographed over silica gel using a mixture of ethyl acetate and pet. ether (2: 8)

Conditions: temp:0.00; pressure:0.00; stir: