Facile acylation of α-chitin in ionic liquid

Hiroki Hirayama; Junpei Yoshida; Kazuya Yamamoto; Jun-Ichi Kadokawa

doi:10.1016/j.carbpol.2018.08.010

Facile acylation of α-chitin in ionic liquid

Carbohydr Polym. 2018 Nov 15:200:567-571. doi: 10.1016/j.carbpol.2018.08.010. Epub 2018 Aug 12.

Authors

Hiroki Hirayama¹, Junpei Yoshida¹, Kazuya Yamamoto¹, Jun-Ichi Kadokawa²

Affiliations

¹ Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
² Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan. Electronic address: kadokawa@eng.kagoshima-u.ac.jp.

PMID: 30177200
DOI: 10.1016/j.carbpol.2018.08.010

Abstract

Based on the fact that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr), efficiently dissolved α-chitin, this study investigated the development of facile acylation reactions of α-chitin in AMIMBr media. Under optimal conditions in the presence of pyridine and N,N-dimethyl-4-aminopyridine as base and catalyst, respectively, lauroylation of α-chitin smoothly took place using lauroyl chloride in AMIMBr at 100 °C for 24 h to produce a chitin laurate with a high degree of substitution (DS). Chitin acylates having different substituents were also synthesized by acylation of α-chitin using various acyl chlorides under the same conditions. In addition to IR analysis of the products, ¹H NMR measurement was allowed for structure confirmation owing to the dissolution of the high DS derivatives in CDCl₃/CF₃CO₂H mixed solvents.

Keywords: Acyl chloride; Acylation; Chitin; Derivative; Ionic liquid.