Dimethylformamide → 3-(Benzyloxy)-4-bromophenol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a 0° C. slurry of 1.7 g. (42.5 mmoles) of potassium hydride in 35 ml. of N,N-dimethylformamide is slowly added a solution of 7.22 g. (38.2 mmoles) of 4-bromoresorcinol. The resultant mixture is stirred for 30 minutes and then 4.54 ml. (38.2 mmoles) of benzyl bromide is slowly added. The reaction mixture is stirred 3 hours longer at 0° C. and then added to 200 ml. of cold water and 200 ml. of ether. The ether extract is washed twice with 200 ml. portions of water, dried over magnesium sulfate and evaporated to an oil. The crude oil is purified via column chromatography on 400 g. of silica gel eluted with 25% ether-pentane to yield (in order of elution) 2.2 g. (16%) of 2,4-dibenzyloxybromobenzene, 0.21 g. (2%) of 5-benzyloxy-2-bromophenol and 3.52 g. (33%) of 3-benzyloxy-4-bromophenol.

Herkunft & Nachweise