Ethyl bromoacetate → (6-Benzyloxy-pyridin-3-yloxy)-acetic acid ethyl ester
Reaktionsgleichung
[CH2:1]([O:8][C:9]1[N:14]=[CH:13][C:12]([OH:15])=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O1CCCC1.Br[CH2:22][C:23]([O:25][CH2:26][CH3:27])=[O:24]>>[CH2:26]([O:25][C:23](=[O:24])[CH2:22][O:15][C:12]1[CH:13]=[N:14][C:9]([O:8][CH2:1][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=2)=[CH:10][CH:11]=1)[CH3:27]Komponenten
4
Versuchsvorschrift
To an ice-cold solution of 0.5 g (2.5 mmol) 6-benzyloxy-3-hydroxypyridine (commercially available) in 5 mL tetrahydrofuran 0.12 g (2.7 mmol) sodium hydride (55% dispersion in mineral oil) was added. After the vigorous gas evolution had ceased the reaction mixture was stirred for 15 min. and then 0.41 mL (3.72 mmol) ethyl bromoacetate were added dropwise. The light brown suspension was stirred for 1 h at room temperature, poured on water and extracted three times with ethyl acetate. The organic layers were washed with brine, dried over magnesium sulfate, filtered, treated with silica gel and evaporated. The resulting solid is purified by silica gel chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) with a gradient of heptane:ethyl acetate (100:0 to 70:30) to give the desired product as a colorless oil (90%). MS (Turbo Spray): m/z=288.0 [M+H].