Liquid-Phase Oxidation of Butene–Butane Mixtures with N₂O to Ketones and Aldehydes

Abstract

Conventional methods for the production of ketones and aldehydes are usually quite complicated and require the use of specific catalysts. Thus, methyl ethyl ketone (MEK) is currently manufactured through a two-step catalytic process involving the hydration of n-butenes and dehydration of the formed alcohol. The non-catalytic oxidation of olefins with nitrous oxide (N2O) via the 1,3-dipolar cycloaddition mechanism opens a potential route for the direct synthesis of carbonyl compounds. In this work, the oxidation of the commercial butene–butane mixture (BBM) with N2O in the liquid phase at 220–260 °C and elevated pressure was studied using the gas chromatography, gas chromatography–mass spectrometry, and nuclear magnetic resonance analytical methods. It was shown that only butene isomers in BBM are selectively oxidized by N2O to yield ketones and aldehydes with a total selectivity of up to 86.6%, including MEK as the major product. During oxidation, alkyl-substituted cyclopropanes are also formed from butenes with a selectivity of up to 15%.