6-bromo-1,4-dihydro-3,1-benzoxazin-2-one

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

Procedure: To a solution of (2-amino-5-bromophenyl)methanol (772 mg, 3.8 mmol) in 15 ml THF was added triphosgene (1.03 g, 3.8 mmol) under nitrogen. After precipitation of a colorless solid, stirring was continued for 20 min before water was added. The solution was extracted several times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4 and evaporated, affording 6-bromo-1H-benzo[d][1,3]oxazin-2(4H)-one (830 mg, 3.64 mmol, 96%) as colorless solid. After precipitation of a colorless solid was added The solution was extracted several times with ethyl acetate The combined organic layers were washed with brine dried over MgSO4 evaporated

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

Procedure: To a solution of (2-amino-5-bromophenyl)methanol (772 mg, 3.8 mmol) in 15 ml THF was added triphosgene (1.03 g, 3.8 mmol) under nitrogen. After precipitation of a colorless solid, stirring was continued for 20 min before water was added. The solution was extracted several times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4 and evaporated, affording 6-bromo-1H-benzo[d][1,3]oxazin-2(4H)-one (830 mg, 3.64 mmol, 96%) as colorless solid. After precipitation of a colorless solid was added The solution was extracted several times with ethyl acetate The combined organic layers were washed with brine dried over MgSO4 evaporated

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

Procedure: To a solution of (2-amino-5-bromophenyl)methanol (772 mg, 3.8 mmol) in 15 ml THF was added triphosgene (1.03 g, 3.8 mmol) under nitrogen. After precipitation of a colorless solid, stirring was continued for 20 min before water was added. The solution was extracted several times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4 and evaporated, affording 6-bromo-1H-benzo[d][1,3]oxazin-2(4H)-one (830 mg, 3.64 mmol, 96%) as colorless solid. After precipitation of a colorless solid was added The solution was extracted several times with ethyl acetate The combined organic layers were washed with brine dried over MgSO4 evaporated

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

Procedure: To a solution of (2-amino-5-bromophenyl)methanol (772 mg, 3.8 mmol) in 15 ml THF was added triphosgene (1.03 g, 3.8 mmol) under nitrogen. After precipitation of a colorless solid, stirring was continued for 20 min before water was added. The solution was extracted several times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4 and evaporated, affording 6-bromo-1H-benzo[d][1,3]oxazin-2(4H)-one (830 mg, 3.64 mmol, 96%) as colorless solid. After precipitation of a colorless solid was added The solution was extracted several times with ethyl acetate The combined organic layers were washed with brine dried over MgSO4 evaporated

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

Procedure: To a solution of sodium hydride (55 wt % in mineral oil, 1.36 g, 31.2 mmol) in N,N-dimethylformamide (37 ml) was added 6-bromo-1,4-dihydro-2H-3,1-benzoxazin-2-one (5.93 g, 26.0 mmol) in N,N-dimethylformamide (37 ml) at 0° C. The mixture was stirred at room temperature for one hour, then 2-(chloromethoxy)ethyltrimethylsilane (4.77 g, 28.6 mmol) was added at 0° C. The mixture was stirred at room temperature overnight. The mixture was partitioned between water and ethyl acetate. The organic layer was washed with water (four times), dried over sodium sulfate, and concentrated in vacuo. The residue was purified by silica gel column chromatography (eluent; hexane/ethyl acetate=90/10 to 60/40) to afford 6-bromo-1-{[2-(trimethylsilyl)ethoxy]methyl}-1,4-dihydro-2H-3,1-benzoxazin-2-one as a pale yellow solid (7.96 g, 22.2 mmol, 85%). The mixture was stirred at room temperature overnight The mixture was partitioned between water and ethyl acetate The organic layer was washed with water (four times) dried over sodium sulfate concentrated in vacuo The residue was purified by silica gel column chromatography (eluent; hexane/ethyl acetate=90/10 to 60/40)