Reaktion #1718138

Reaktionsgleichung

NaBH4

5-bromonicotinaldehyde

ethanesulfonamide

toluene

→

N-((5-bromopyridin-3-yl)methyl)ethanesulfonamide

Lösungsmittel

MeOH

Water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added dropwise
2. 2
   EinengenThe mixture is concentrated in vacuo
3. 3
   workup.STIRRINGThe mixture is stirred at 0° C. for 30 min
4. 4
   workup.STIRRINGthe mixture is stirred for 5 min
5. 5
   FiltrationThe suspension is filtered through a pad of celite
6. 6
   WaschenThe celite layer is washed with DCM (50 mL×3)
7. 7
   EinengenThe filtrate is concentrated in vacuo
8. 8
   ExtraktionThe resulting aqueous phase is extracted with DCM (500 mL)
9. 9
   Trocknenthe organic phase is dried over Na2SO4, silica gel (20 g)
10. 10
    workup.ADDITIONadded
11. 11
    Einengenconcentrated in vacuo
12. 12
    SonstigeThe residue is purified by silica chromatography
13. 13
    Wascheneluting with a 0 to 7% MeOH-DCM gradient

Vorschrift

A flask is charged with 5-bromonicotinaldehyde (1.15 g, 6.18 mmol), ethanesulfonamide (1.35 g, 12.37 mmol) and toluene (120 mL), and titanium isopropoxide (2.64 g, 9.27 mmol) is added dropwise. The mixture is stirred at 120° C. overnight. The mixture is concentrated in vacuo. The residue is taken up in DCM (100 mL) and MeOH (100 mL) and NaBH4 (0.468 g, 12.37 mmol) is added at 0° C. The mixture is stirred at 0° C. for 30 min. Water (50 mL) is then added and the mixture is stirred for 5 min. The suspension is filtered through a pad of celite. The celite layer is washed with DCM (50 mL×3). The filtrate is concentrated in vacuo. The resulting aqueous phase is extracted with DCM (500 mL) and the organic phase is dried over Na2SO4, silica gel (20 g) added, and concentrated in vacuo. The residue is purified by silica chromatography eluting with a 0 to 7% MeOH-DCM gradient to give N-((5-bromopyridin-3-yl)methyl)ethanesulfonamide. MS (ESI) m/z 278.9, 280.8, (M+H)+.

Quelle