Ethyl bromoacetate → Ethyl 2,4-dibenzyloxyphenoxyacetate

Reaktionsgleichung

[CH2:1]([O:8][C:9]1[CH:14]=[C:13]([O:15][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH:12]=[CH:11][C:10]=1[OH:23])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H-].[Na+].Br[CH2:27][C:28]([O:30][CH2:31][CH3:32])=[O:29]>>[CH2:1]([O:8][C:9]1[CH:14]=[C:13]([O:15][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH:12]=[CH:11][C:10]=1[O:23][CH2:27][C:28]([O:30][CH2:31][CH3:32])=[O:29])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Komponenten

Edukt 3

HCID 7748Ethyl bromoacetate

HCID 24758Sodium hydride

HCID 106383482,4-Dibenzyloxyphenol

Produkt 1

HCID 10763088Ethyl 2,4-dibenzyloxyphenoxyacetateAusbeute 80,6 %

Versuchsvorschrift

2,4-Dibenzyloxyphenol (3.1 g) is added to a stirred suspension of sodium hydride (0.44 g, 60% dispersion in mineral oil) and the mixture is heated at reflux for 30 minutes. Refluxing is allowed to abate when ethyl bromoacetate (1.8 g) is added and the mixture heated at reflux for 1 hour. The reaction mixture is evaporated and the residue partitioned between ethyl acetate and water. The organic phase is washed with water, dried over magnesium sulphate and evaporated to give a light brown oil which is purified by column chromatography on silica eluting with dichloromethane. Fractions homogeneous in the required product are combined and evaporated. The residue is triturated with pentane to give ethyl (2,4-dibenzyloxyphenoxy)acetate (3.2 g) as a white powder, m.p. 62-64° C. [Elemental analysis:- C,73.3; H,6.13%. Calculated:- C,73.5; H,6.13%].