Synthesis and late-stage C–H functionalization of papaverines

An efficient synthesis and late-stage C-H functionalization of papaverine under volatile solvent-free conditions are reported. This methodology demonstrates significant potential for applications in the active pharmaceutical ingredient (API) industry, particularly for the sustainable and solvent-free synthesis of papaverine. A plausible reaction mechanism was meticulously elucidated through comprehensive control experiments. Additionally, gram-scale synthesis of papaverine and its functionalized derivatives was successfully accomplished. Furthermore, the photophysical properties of the synthesized functionalized papaverine compounds were thoroughly investigated using absorption and emission spectroscopy.