Addition-Elimination reaction route results in the formation of Py-N-ene. Starting with XIII-Br, we used QST3 method to compute the final reaction profile for the formation of Py-N-ene (R5, Scheme 6). We proposed an addition-elimination reaction route between XIII-Br and the surrounding NaH which formed a low energy adduct, XV-Br. We rationalized this step by calculating the Fukui index of the electrophilic carbon alpha to pyrazolyl nitrogen during a nucleophilic attack of surrounding NaH (fA + (Cα) = 0.623). Specifically, we show the site of addition reaction by mapping the electrostatic potential around XIII-Br as the electronic isodensity surface (inset, Scheme 6). Following the addition reaction a concomitant β-elimination of acetonitrilic ion, rationalized by the calculated reduced bond order between the Cα and Cβ (inset, Scheme 6), led to the formation of experimentally observed unexpected product Py-N-ene.