Reaktion #52336

Reaktionsgleichung

6-tert-butoxycarbonylmethyl-2,3-dihydro-pyrido[3,2-b][1,4]oxazine-4-carboxylic acid tert-butyl ester

lithium borohydride

→

product

Ausbeute 94.9%

2-(3,4-dihydro-2h-pyrido[3,2-b][1,4]oxazin-6-yl)-ethanol

Ausbeute 94.9%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was refluxed overnight
2. 2
   Temperaturcooled in an ice-bath
3. 3
   workup.ADDITIONAqueous solution of naoh (0.36 ml, 5%) was added
4. 4
   SonstigeThe ice-bath was removed
5. 5
   workup.ADDITIONAdditional h2o (0.36 ml) was added
6. 6
   workup.ADDITIONCelite and na2so4 were added
7. 7
   FiltrationThe mixture was filtered through celite
8. 8
   Waschenthe celite washed with etoac
9. 9
   WaschenThe filtrate and washing
10. 10
    Sonstigedried over na2so4
11. 11
    Einengenconcentrated
12. 12
    Sonstigeflash chromatographed on silica gel
13. 13
    Wascheneluting with meoh/dcm (1, 2, 3, 4%)

Vorschrift

To a solution of 6-tert-butoxycarbonylmethyl-2,3-dihydro-pyrido[3,2-b][1,4]oxazine-4-carboxylic acid tert-butyl ester (350 mg, 1mmol) in THF (4.0 ml) was added a solution of lithium borohydride (0.6 ml, 2.0 m in thf). The mixture was refluxed overnight, then cooled in an ice-bath. Aqueous solution of naoh (0.36 ml, 5%) was added. The ice-bath was removed. Additional h2o (0.36 ml) was added and the mixture stirred for 10 min. Celite and na2so4 were added. The mixture was filtered through celite, and the celite washed with etoac. The filtrate and washing were combined, dried over na2so4, concentrated, and flash chromatographed on silica gel, eluting with meoh/dcm (1, 2, 3, 4%) to give the product (171 mg, 94% yield) as a yellow oil. 1H NMR (CDCl3) δ 6.90 (d, 1H, J=7.8 Hz), 6.39 (d, 1H, J=7.7 Hz), 4.85 (bs, 1H), 4.20 (t, 2H, J=4.4 Hz), 3.91 (t, 2H, J=5.5 Hz), 3.69-3.52 (m, 2H), 2.78 (t, 2H, J=5.6 Hz).

Quelle