[1,2,4]Triazolo[4,3-a]pyridin-3(2H)-one; 1,2,4-Triazolo[4,3-a]pyridine-3(2H)-one; s-Triazolo[4,3-a]pyridin-3-ol; 3-Hydroxytriazolo[4,3-a]pyridine; [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one