Transition metal free Brønsted acid mediated synthesis of pyrido[1,2-a]indole scaffolds has been developed through aza-Nazarov type cyclization of readily available diaryl(2-pyridyl)methanol using formic acid for the synthesis of biologically and medicinally important pyrido[1,2-a]indole, indolo[1,2-a]quinoline and pyrimido[1,2-a]indole derivatives.