Ethyl bromoacetate → HCID 57786461、化合物

To a solution of 2-butyl-2H-benzo[b][1,4]thiazin-3(4H)-one (6.3 mmol, 1400 mg) in DMF (5 ml) was added NaH (6.9 mmol, 167 mg) and the reaction mixture was stirred at room temperature for 1 h before the dropwise addition of ethyl bromoacetate (6.3 mmol, 1052 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 (10 ml) and 1 N NaOH (10 ml) and stirred at room temperature for 2 h. 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)=280.2; tR=3.01.