Synthesis of 3-phenyl-4-phenylvinyl Benzopyranones and the Corresponding 2,2-dimethyl-benzopyrans with Structural Similarity to Estradiol, as Estrogen Receptor Ligands

7-Methoxy-3-phenyl-4-phenylvinyl benzopyran-2-ones and the corresponding 2,2-dimethyl-benzopyrans, substituted with different alkylamino residues were synthesized. Except compound 13e, all compounds showed high level of estrogen agonistic activity (>81 %) whereas, compounds 13 b-e and 15a showed significant estrogen antagonistic activity (>20 %). X-Ray analysis of a 7-methoxy-3-phenyl-4-phenylvinyl benzopyran-2-one derivative 13d showed its structural resemblance to endogenous estrogen, 17β-estradiol. Estrogenic and antiestrogenic activities of these derivatives demonstrate their estrogen receptor (ER) binding ability. The lack of hydroxyl groups at appropriate positions resulted in poor Relative Binding Affinity (RBA).