2-ethyl-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:; See reaction.notes.procedure_details.

Procedure: 0.25 g of 2-ethyl-1,4-benzoxazin-3-one is stirred in 2 ml of pyridine with 95 mg of phosphorus pentasulfide. The reaction is completed by reflux-boiling. It is poured onto water, extracted with ethyl acetate, and the organic phase is washed with brine. It is dried with magnesium sulfate and concentrated by evaporation. After column chromatography with hexane/ethyl acetate, 220 mg of product results. by reflux-boiling It is poured onto water extracted with ethyl acetate the organic phase is washed with brine It is dried with magnesium sulfate concentrated by evaporation

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

Procedure: 0.25 g of 2-ethyl-1,4-benzoxazin-3-one is stirred in 2 ml of pyridine with 95 mg of phosphorus pentasulfide. The reaction is completed by reflux-boiling. It is poured onto water, extracted with ethyl acetate, and the organic phase is washed with brine. It is dried with magnesium sulfate and concentrated by evaporation. After column chromatography with hexane/ethyl acetate, 220 mg of product results. by reflux-boiling It is poured onto water extracted with ethyl acetate the organic phase is washed with brine It is dried with magnesium sulfate concentrated by evaporation

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

Procedure: To a solution of 2-ethyl-2H-benzo[b][1,4]oxazin-3(4H)-one (1.5 mmol, 260 mg) in DMF (2 ml) was added NaH (1.8 mmol, 43 mg) and the reaction mixture was stirred at room temperature for 1 h before the dropwise addition of ethyl bromoacetate (1.5 mmol, 250 mg). The reaction mixture was stirred at room temperature overnight, diluted with water and extracted with ethyl acetate. The organic layer was washed with 1N HCl, Sat. NaHCO3, dried over Na2SO4 and evaporated to dryness. The crude compound was dissolved in MeOH (3 ml) and 1 N NaOH (3 ml) and stirred for 2 h at room temperature. The MeOH was removed under reduced pressure and the resulting aqueous solution extracted with EtOAc. The aqueous layer was acidified to pH 2 with 1N HCl and extracted with EtOAc. The organic phase was dried over Na2SO4 and the solvent was evaporated to give the title compound. LC/MS (10% to 99%): M/Z (M+H)+ (obs)=236; tR=2.4. extracted with ethyl acetate The organic layer was washed with 1N HCl, Sat. NaHCO3 dried over Na2SO4 evaporated to dryness The crude compound was dissolved in MeOH (3 ml) 1 N NaOH (3 ml) and stirred for 2 h at room temperature The MeOH was removed under reduced pressure the resulting aqueous solution extracted with EtOAc extracted with EtOAc The organic phase was dried over Na2SO4 the solvent was evaporated

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

Procedure: To a solution of 2-bromobutanoic acid (11 mmol, 2145 mg) in DMF (10 ml) was added EDC (12 mmol, 2.3 g) and HOBt (5 mmol, 675 mg) followed by the addition of 2-aminophenol (10 mmol, 1091 mg). The reaction mixture was stirred at room temperature for 2 h, diluted with water and extracted with ethyl acetate. The organic phase was washed with water, brine, dried over Na2SO4 and concentrated under reduced pressure. To the crude product in DMF (5 ml) was added K2CO3 (1.6 g) and the reaction mixture was stirred at room temperature overnight. The reaction mixture was diluted with water and extracted with EtOAc. The organic layer was washed with 1N HCl, Sat. NaHCO3, dried over Na2SO4 and evaporated to dryness. Purification by column chromatography gave the desired product as a white solid. LC/MS (10% to 99%): M/Z (M+H)+ (obs)=178; tR=2.36. extracted with ethyl acetate The organic phase was washed with water, brine dried over Na2SO4 concentrated under reduced pressure To the crude product in DMF (5 ml) was added K2CO3 (1.6 g) the reaction mixture was stirred at room temperature overnight The reaction mixture was diluted with water extracted with EtOAc The organic layer was washed with 1N HCl, Sat. NaHCO3 dried over Na2SO4 evaporated to dryness Purification by column chromatography

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

Procedure: 0.25 g of 2-ethyl-1,4-benzoxazin-3-one is stirred in 2 ml of pyridine with 95 mg of phosphorus pentasulfide. The reaction is completed by reflux-boiling. It is poured onto water, extracted with ethyl acetate, and the organic phase is washed with brine. It is dried with magnesium sulfate and concentrated by evaporation. After column chromatography with hexane/ethyl acetate, 220 mg of product results. by reflux-boiling It is poured onto water extracted with ethyl acetate the organic phase is washed with brine It is dried with magnesium sulfate concentrated by evaporation