Journal : J Med Chem
Title : Selective IKur Inhibitors for the Potential Treatment of Atrial Fibrillation: Optimization of the Phenyl Quinazoline Series Leading to Clinical Candidate 5-[5-Phenyl-4-(pyridin-2-ylmethylamino)quinazolin-2-yl]pyridine-3-sulfonamide.
Year : 2017
Volume : 60
Issue : 9
First Page : 3795
Last Page : 3803
Authors : Gunaga P, Lloyd J, Mummadi S, Banerjee A, Dhondi NK, Hennan J, Subray V, Jayaram R, Rajugowda N, Umamaheshwar Reddy K, Kumaraguru D, Mandal U, Beldona D, Adisechen AK, Yadav N, Warrier J, Johnson JA, Sale H, Putlur SP, Saxena A, Chimalakonda A, Mandlekar S, Conder M, Xing D, Gupta AK, Gupta A, Rampulla R, Mathur A, Levesque P, Wexler RR, Finlay HJ.
Abstract : We have recently disclosed 5-phenyl-N-(pyridin-2-ylmethyl)-2-(pyrimidin-5-yl)quinazolin-4-amine 1 as a potent IKur current blocker with selectivity versus hERG, Na and Ca channels, and an acceptable preclinical PK profile. Upon further characterization in vivo, compound 1 demonstrated an unacceptable level of brain penetration. In an effort to reduce the level of brain penetration while maintaining the overall profile, SAR was developed at the C2' position for a series of close analogues by employing hydrogen bond donors. As a result, 5-[5-phenyl-4-(pyridin-2-ylmethylamino)quinazolin-2-yl]pyridine-3-sulfonamide (25) was identified as the lead compound in this series. Compound 25 showed robust effects in rabbit and canine pharmacodynamic models and an acceptable cross-species pharmacokinetic profile and was advanced as the clinical candidate. Further optimization of 25 to mitigate pH-dependent absorption resulted in identification of the corresponding phosphoramide prodrug (29) with an improved solubility and pharmacokinetic profile.
