Benzene fused monocyclic enediynyl amides: synthesis, reactivity and DNA-Cleavage activity in comparison to the corresponding sulfonamides

Monocyclic enediynyl amides 2a–2c have been synthesized via the corresponding free amine 5. Kinetic studies in chloroform revealed the reactivity of these amides towards Bergman cyclization to be less than that of the corresponding sulfonamides. However, differential scanning calorimetry (DSC) measurements in the solid state and DNA-cleavage studies in aqueous buffer showed higher reactivity for the amides than the sulphonamides.