Micro-photo-flow reactor system for fused N-heteroaryl scaffold synthesis and late-stage functionalization of pyrazolopyridines.

Late-stage functionalization (LSF) of active pharmaceutical ingredients can provide a straightforward approach to efficient de novo design and synthesis of drug molecules for structural activity relationship studies (SARS). Herein, we have developed a visible-light-driven modular micro-flow reactor consisting of an integrated post-synthetic work-up that was designed and developed to synthesize a fused N-heteroaryl scaffold and late-stage functionalization of pyrazolopyridines without using any expensive oxidant or additional photo-catalyst (PC).