Conversion of 2′-substituted chalcones in the presence of BSA as evidenced by 1H NMR studies

•The present work deals with the cyclization of o-substituted chalcones to respective flavanones in presence of BSA in aqueous medium in absence of any other reagent.•The results are deduced on the 1H NMR spectral data.•The work can be beneficial in correlating the biological properties of chalcones and flavanones. The emergence of albumin as a biocatalyst has created continuous interest of researchers for its application not only in the field of asymmetric oxidations and reductions but also in chemical reactions such as additions, condensations and eliminations. In the present work we report the cyclization reactions in presence of an albumin protein, Bovine Serum Albumin (BSA). The work is focused on cyclization of 2′-hydroxychalcone and 2′-aminochalcone to flavanones and azaflavanone, respectively. The results are supported by 1H NMR studies.