ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of task-specific imidazolium ionic liquid as an efficient catalyst in acetylation of alcohols, phenols, and amines

Snehkrishn A. Chaubey and Roli Mishra

Department of Physical Sciences, Institute of Advanced Research, Gandhinagar, India

E-mail: rolimishra2@gmail.com

Received: 17 October 2019  Accepted: 30 March 2020

Abstract:

Herein, we report the synthesis of task-specific amino-functionalized imidazolium ionic liquid, acetate1-(2-tert-butoxycarbonylamino-ethyl)-3-methyl-3H-imidazol-1-ium; (Boc-NH-EMIM.OAc), as an efficient catalyst for the acetylation of alcohols, phenols, and amines in the presence of acetic anhydride (acetylating reagent). Remarkably, acetic anhydride in the presence of 10 mol% of catalyst (Boc-NH-EMIM.OAc) under solvent-free conditions showed excellent acetylation activity in shorter duration of time. On the basis of this, a general procedure for acetylation of alcohols, phenols, and amines has been developed. The ionic liquid (Boc-NH-EMIM.OAc) can be readily recovered and reused successfully up to four consecutive cycles without any significant loss of its catalytic activity. We have been able to show that this acetylating method has many advantages. It gives high yields, takes shorter time, and develops the possibility of benign environmental-friendly process.

Keywords: Amino-functional imidazolium ionic liquids; Acetylation; Catalyst; Acetic anhydride; Solvent-free condition; Boc-NH-EMIM.OAc

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01150-0

Chemical Papers 74 (10) 3259–3268 (2020)