Choline chloride–ZnCl₂: Recyclable and efficient deep eutectic solvent for the [2+3] cycloaddition reaction of organic nitriles with sodium azide

ABSTRACT

Herein we report first time choline chloride–zinc chloride based deep eutectic solvent is a green and efficient reaction medium for the [2+3] cycloaddition reaction of organic nitriles with sodium azide to afford the corresponding 5-substituted 1H-tetrazoles. The present method provides an environment-friendly route, short reaction times with excellent yields, safe process, and simple workup which make this method an attractive and useful contribution to the existing conventional processes for the synthesis of 5-substituted 1H-tetrazoles.

GRAPHICAL ABSTRACT

KEYWORDS:

• Choline chloride
• click chemistry
• deep eutectic solvent
• green chemistry
• tetrazoles

Acknowledgment

One of the authors, Swapnil A. Padvi, is sincerely thankful to the University Grants Commission, New Delhi, India for the award of “Rajiv Gandhi National Fellowship” (RGNF). The authors are also thankful to the University Grand Commission, New Delhi, India for facilities under the UGC-SAP-DSA-I programme to North Maharashtra University (NMU) and SAIF, Punjab University, for providing necessary characterization facilities.