Synthesis of 1,4-dioxene from diethylene glycol in the presence of bifunctional copper-containing catalysts. Effect of support on the selectivity of dioxene formation

Article abstract of DOI:10.1007/BF01169348

In the synthesis of 1,4-dioxene from diethylene glycol in the presence of a bifunctional copper-containing catalyst, the composition of the by-products has been studied and the effect of the support on the overall direction of the reactions has been investigated. It has been established that on Cu/SiO₂, 1,4-dioxanone is formed together with dioxene, the yield of the former increasing with an increase in the content of copper in the catalyst. This is due to an increase in the dehydrogenating function of the latter. On the more acidic Cu/Al₂O₃, 1,4-dioxane is mainly obtained together with, to a lesser degree, methyl-1,3-dioxolane. This is due to the predominance of dehydration reactions followed by isomerization. Dioxene, dioxane, and methyldioxolane are formed on Cu/HNaY, and the yield of the latter increases with an increase in the degree of acidity (degree of decationization) of the zeolite. It is possible to increase the selectivity of dioxene formation substantially with the use of a catalyst with a moderately acidic zeolite, by varying its copper content and by dilution with water vapor. 1996 Plenum Publishing Corporation.