Green synthesis of 2-pyrazinones in deep eutectic solvents: From α-chloro oximes to peptidomimetic scaffolds

A novel and green synthesis of 2-pyrazinones in deep eutectic solvents (DESs) is described. Treatment of aromatic alpha-chloro oximes with aliphatic amines at 110 degrees C in choline chloride based DESs resulted in a straightforward and efficient assembly of 1,3,5-trisubstituted-2(1H)-pyrazinones. The protocol, featuring mild reaction conditions and avoiding common volatile organic solvents, affords a safe and sustainable approach to original peptidomimetic scaffolds. (C) 2017 Elsevier Ltd. All rights reserved.