Novel biocompatible glucose-based deep eutectic solvent as recyclable medium and promoter for expedient multicomponent green synthesis of diverse three and four substituted pyrazole-4-carbonitrile derivatives Reza Aryan 1 • Hamid Beyzaei 1 • Masoomeh Nojavan 1 • Meysam Rezaei 1 Received: 30 November 2016 / Accepted: 11 February 2017 Ó Springer Science+Business Media Dordrecht 2017 Abstract A novel biocompatible glucose-based deep eutectic solvent (DES) is reported for the first time in the multicomponent synthesis of diverse three and four substituted pyrazole-4-carbonitrile derivatives under catalyst-free condition without using any harmful organic solvent even for purification of the products. The desired products were obtained with high degree of diversity from the reaction of malononitrile, aromatic aldehydes and various hydrazine derivatives as nitrogen source at room temperature within short reaction times and good to excellent pro- duct yields. The deep eutectic solvent was also recycled and reused at least four times with only a slight loss of efficiency. A plausible mechanism was also proposed indicating the role of DES hydrogen bonding in the reaction promotion. Keywords Glucose-based deep eutectic solvents Á Green chemistry Á Multicomponent reaction Á Pyrazole-4-carbonitrile derivatives Á Catalyst-free conditions Á Recyclable medium Introduction Green chemistry considerations have recommended the application of biocompat- ible building blocks such as natural products as reactant, medium and/or catalyst in designing novel synthetic protocols to address the traditional inadequacies of organic synthesis [1]. These thoughts dramatically influenced organic chemists’ research ideas more recently especially by the development of a novel class of alternative solvents called deep eutectic solvents [2, 3]. Deep eutectic solvents began to become very popular at the first years of the present century. These media & Reza Aryan rezaaryanchemist@yahoo.com; rezaaryan@uoz.ac.ir 1 Department of Chemistry, Faculty of Science, University of Zabol, P. O. Box 9861335856, Zabol, Iran 123 Res Chem Intermed DOI 10.1007/s11164-017-2908-5