Synthesis of 5-cyanopyrazolo[1,5-a]pyridine derivatives via tandem reaction and their optical properties

[Display omitted] A series of 2- and 2,4-substituted 5-cyanopyrazolo[1,5-a]pyridine derivatives were conveniently synthesized by a one-pot tandem reaction under mild conditions in moderate yields. The reaction mechanism was also proposed. Some of the 2,4-substituted pyrazolo[1,5-a]pyridines display blue fluorescence not only in dilute solution but also in the solid state.