Synthesis and structural analysis of the active enantiomer of famoxadone, a potent inhibitor of cytochrome bc(1)

Famoxadone is a newly commercialized fungicide and potent Q(o)-site inhibit or of cytochrome bet. The S-(-)-enantiomer of famoxadone (the active compon ent) was synthesized by two routes and was analyzed computationally and by X-ray crystallography. The molecule displays an extended conformation with flexibility in the structure imparted by the two terminal phenyl groups. In the crystal lattice, intermolecular hydrogen bonds occur between the NH an d the oxygen atoms of the heterocycle. (C) 2000 Elsevier Science Ltd. All r ights reserved.