Hydrogen Bromide → 1,3-Propanediol, 2-(bromomethyl)-2-(hydroxymethyl)-

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Reaction Steps

200 g (1.47 mol) of pentaerythritol (PE), 1.51 of glacial acetic acid and 17 ml of 48% HBr are refluxed for 1.5 h. A further 170 ml of 48% HBr are added and the reaction mixture is then boiled for another 3 h. The same procedure is repeated with the addition of 96 ml of HBr. The glacial acetic acid and water are then distilled off completely, 750 ml of 98% ethanol and 50 ml of 48% HBr are added to the viscous residue and approx. 500 ml of ethanol are removed by slow distillation. A further 750 ml of ethanol are subsequently added and then distilled off completely. After the addition of 500 ml of toluene, the solvent is distilled off and the same procedure is repeated. The viscous residue is boiled for several hours with 500 ml of dry ether, with stirring, until a white solid deposits. The solid is filtered off with suction, washed with dry ether, dried and recrystallized from chloroform/ethyl acetate=3:2. Yield: 50%. M.p.=75-76° C.

Provenance & Evidence