Isolation of 1,2-epoxybutane-3-ol and 2,3-epoxybutane-1-ol from post-reaction mixtures

Attempts were made to isolate 1,2-epoxybutane-3-ol and 2,3-epoxybutane-1-ol from post-reaction mixtures left after the epoxidation of 1-butene-3-ol and 2-butene-1-ol with hydrogen peroxide by thin film distillation. From the raw mixture containing about 8.3 wt% of the epoxide at the first stage the concentration of epoxide is increased to 32 wt%. At the second stage of distillation the epoxide fraction is concentrated to about 76 wt%. After the third stage of thin film distillation the epoxide fraction of 99.6% purity can be obtained. The concentration of this fraction by azeotropic distillation with n-propanol as an azeotropic agent permits obtaining epoxide of 99.6 wt% purity.