反应详情

温度

25 °C

To a stirred solution of 1H-pyrido-[3,4-b][1,4]oxazine-2-(3H)one (3 g, 21 mmol) in tetrahydrofuran (150 ml) was added rapidly a borane/dimethyl sulfide solution (52 ml of a 2M solution in THF, 5 eq) at 25° C. over 15 minutes. The reaction mixture was stirred at 25° C. for 2 hours and quenched with 5 ml of water. The solvent was removed in vacuo using a rotary evaporator and the residue treated with aqueous 1M HCl with stirring. The water was removed and the residue chromatographed on silica gel using CH2Cl2 /MeOH/NH4OH (90/10/1) to give 2 g (70%) of titled product. m.p. 167°-169° C. The structural assignment is supported by the proton NMR spectrum.

1. customquenched with 5 ml of water
2. customThe solvent was removed in vacuo
3. customa rotary evaporator
4. additionthe residue treated with aqueous 1M HCl
5. stirringwith stirring
6. customThe water was removed
7. customthe residue chromatographed on silica gel