Manipulating a Multicomponent Reaction:A Straightforward Approach to Chromenopyrazole Hybrid Scaffolds

An easy access to hybrid bioactive molecules, such as the chromenopyrazoles, is described based on the three-component reactions of 3-formylchromones, arylhydrazines, and acetylenedicarboxylates. By manipulating the reaction, four different scaffolds can be derived in an easy, versatile, and robust fashion. To underscore the potential, generality, and diversity that can be generated, representative libraries of each scaffold were synthesized. Moreover, a comprehensive NMR analysis with full assignment of all H-1 and C-13 NMR chemical shifts has been performed.