反应详情

温度

45 °C

A solution of 3,4-dihydro-3-oxo-2H-pyrido[3,2-b]-1,4-oxazin-2-carboxylic acid ethyl ester (1.10 g, 5.0 mmol) in THF (50 mL) was added over 5 min to a stirred mixture of LiAlH4 (0.38 g, 10 mmol) and THF (20 mL) at 40° C. The mixture was stirred at 45° C. for 30 min and at reflux for 4 h. The mixture was allowed to attain room temperature and excess LiAlH4 decomposed with 50% aqueous NaOH. The mixture was filtered through Celite, and the filtrate was concentrated. The residue (0.42 g) was extracted with CH2Cl2 and the extract was concentrated and purified by chromatography on silica gel (gradient: PhMe to PhMe/MeOH/Et3N, 8:1:1) to give the product as a white solid: yield 0.11 g (13%); mp 123-124° C. Anal. (C8H10N2O2) C, H, N.

1. temperatureat reflux for 4 h
2. customto attain room temperature
3. filtrationThe mixture was filtered through Celite
4. concentrationthe filtrate was concentrated
5. extractionThe residue (0.42 g) was extracted with CH2Cl2
6. concentrationthe extract was concentrated
7. custompurified by chromatography on silica gel (gradient: PhMe to PhMe/MeOH/Et3N, 8:1:1)