N‐arylthiophene‐2‐carboxamidoxime derivatives (a‐e) were synthesized by using two methods and then subjected to thermolysis at 200–250 °C for 2 h under nitrogen atmosphere either alone or in the presence of tetralin and/or naphthalene as radical scavengers yielded imidazole, oxazole, triazine and amide derivatives. The pyrolysates from both reactions were separated with their constituents by column chromatography and analyzed then identified 1H NMR, 13C NMR and GC‐MS. A plausible mechanism is suggested through two competitive pathways involving the homolysis of N‐O and/or C‐N bonds to account for the thermolysis products.