Design, synthesis and evaluation of dual pharmacology β2-adrenoceptor agonists and PDE4 inhibitors

A novel series of formoterol-phthalazinone hybrids were synthesised and evaluated as dual pharmacology β2-adrenoceptor agonists and PDE4 inhibitors. Most of the hybrids displayed high β2-adrenoceptor agonist and moderate PDE4 inhibitory activities. The most potent compound, (R,R)-11c, exhibited agonist (EC50 = 1.05 nM, pEC50 = 9.0) and potent PDE4B2 inhibitory activities (IC50 = 0.092 μM).