Morpholinium and Piperidinium Based Deep Eutectic Solvents for Synthesis of Pyrazole-5-Carbonitriles, Indoles and Tetrazoles: Bulk Properties via Molecular Dynamics Simulations

Deep eutectic solvents (DES) have gained much popularity in the area of green synthetic chemistry, since they act as excellent alternative to traditional organic solvents for carrying out diverse organic reactions and transformations. Furthermore, they are thermally stable over a wide temperature range, they are non-volatile, inert and can be easily recovered and reused after carrying out reactions. In the present study, we have synthesized morpholine and piperidine based ionic liquids, and combined them with different hydrogen bond donors (urea, diethylene glycol (DEG), carboxylic acid, thiourea, ethanol and methanol) to produce different DES melts. These DES melts were then explored for their potential as catalyst/reaction media for carrying out different organic transformations for synthesis of molecules such as pyrazole-5-carbonitriles 5 a-d, Fisher Indoles 8 a-d and 1H-tetrazoles 10 a-b. In DES, the hydrogen bonded interactions between ionic liquids and hydrogen bond donors are known to be crucial for mediating their catalytic and synthetic efficiency, hence molecular dynamics simulations of these DES melts were carried out to investigate and study these effects.