Pyrazolo[1,5-a]pyridines, a class of fused heteroaromatic bicyclic compounds, have been investigated for their pharmacological and biological activities. They are used as dopamine D2/D3/D4 antagonists, anti-herpetic agents, p38 kinase inhibitors, PI3 kinase inhibitors, antitubercular agents, EP1 receptor antagonists, 5HT3-antagonists, melatonin receptor (MT1/MT2) ligands, Mcl-1Bcl-xL dual inhibitors, and corticotropin-releasing factor 1 antagonists. Pyrazolo[1,5-a]pyridine has been used as a fluorophore in the research of Zhang et al. and exhibited high quantum yield (0.64, pH 2.4), high selectivity and sensitivity, and extremely short response time[1].