Biodegradable Surface Active D-Glucose Based Quaternary Ammonium Ionic Liquids in the Solventless Synthesis of Chloroprene
Karol Erfurt, Marta Markiewicz, Agnieszka Siewniak, Dawid Lisicki, Mariusz Zalewski, Stefan Stolte, Anna Chrobok
Abstract
Five ionic liquids based on a quaternary ammonium core substituted with a D-glucose moiety and alkyl chains of varying length were synthesized as prospective phase-transfer catalysts. The catalytic activity of the obtained ionic liquids was tested in the dehydrochlorination of 3,4-dichloro-1-butene to chloroprene. The reaction proceeded in a two-phase system in the presence of an aqueous solution of sodium hydroxide. The results showed that the longer the alkyl chain in the cation, the higher the activity of the ionic liquid as a phase-transfer catalyst. The tested ionic liquids gave an easily recyclable system compared to classical phase-transfer catalysts that were soluble in the reaction system, with no leaching observed over five cycles (chloroprene yield >99%). The cytotoxicity and biodegradability of a series of synthesized ionic liquids based on D-glucose were determined so that a preliminary hazard assessment could be undertaken.