Bis-pyrrolyl-tetrazolyl derivatives as hybrid polar compounds: A case of lipophilic functional bioisosterism with bis-acetamides

► Functional bioisosterism between the amide moiety and 3-substituted tetrazole. ► Compound 3 induced MEL cell differentiation, but to a lower extent than HMBA. ► Compound 3 caused Hb accumulation close to that of HMBA. ► Cell growth inhibition after 96 h was equal to that of HMBA. ► Compound 3 represents a novel inducer of Hb gene activation in leukemic cells.