Efficient synthesis of epoxybutane from butanediol via a two-step process

Area of Science:

• Chemical Synthesis
• Catalysis
• Green Chemistry

Background:

• Butanediol is a byproduct of coal-to-ethylene glycol processes.
• Efficient utilization of butanediol is desirable.
• Epoxybutane is a valuable chemical intermediate.

Purpose of the Study:

• To develop a novel and green synthetic route for epoxybutane.
• To investigate the catalytic activity of NaAlO2 and ionic liquids.
• To elucidate the mechanism of epoxybutane formation.

Main Methods:

• Synthesis of butenyl carbonate from butanediol and dimethyl carbonate using NaAlO2.
• Decarboxylation of butenyl carbonate using 1-butyl-3-methylimidazolium bromide.
• Density Functional Theory (DFT) calculations to study the reaction mechanism.

Main Results:

• NaAlO2 catalyzed the carbonylation of butanediol with a 96.2% yield of butenyl carbonate under mild conditions.
• 1-butyl-3-methylimidazolium bromide effectively catalyzed the decarboxylation step in batch and continuous processes.
• DFT calculations revealed the crucial role of electrostatic and hydrogen-bond effects in the catalytic mechanism.

Conclusions:

• A novel, green, and cost-effective synthetic pathway for epoxybutane from butanediol was established.
• The study demonstrates a promising application for utilizing butanediol byproduct.
• The findings contribute to the clean manufacture of epoxybutane.