2-Pyridin-2-yl-1H-indole derivatives: Synthesis, estrogen receptor binding affinity, and photophysical properties

A series of novel 2-pyridin-2-yl-1H-indole derivatives (4a–f) was prepared by intramolecular cyclodehydration of α-anilinyl (or 3-anisidyl)-2-pyridin-2-yl-ethanones (2a–f) and their optical spectroscopy and estrogen receptor (ER) binding properties were studied. These compounds showed long wavelength fluorescent emission, which is sensitive to solvent polarity and pH, while indol-6-ols 4b, e, and f displayed reasonably good binding affinities to ER.