Polycyclic heteroaryl substituted triazoles useful as axl inhibitors

#This invention is directed to polycyclic heteroaryl substituted triazoles and pharmaceutical compositions thereof which are useful as inhibitors of the receptor protein tyrosine kinase known as Axl. This invention is also directed to methods of using the compounds and compositions in treating diseases and conditions associated with Axl activity, particularly in treating diseases and conditions associated with angiogenesis and/or cell proliferation.

#All of the protein kinases that have been identified to date in the human genome share a highly conserved catalytic domain of around 300 aa. This domain folds into a bi-lobed structure in which reside ATP-binding and catalytic sites. The complexity of protein kinase regulation allows many potential mechanisms of inhibition including competition with activating ligands, modulation of positive and negative regulators, interference with protein dimerization, and allosteric or competitive inhibition at the substrate or ATP binding sites.

#Axl (also known as UFO, ARK, and Tyro7; nucleotide accession numbers NM—021913 and NM—001699; protein accession numbers NP—068713 and NP—001690) is a receptor protein tyrosine kinase (RTK) that comprises a C-terminal extracellular ligand-binding domain and N-terminal cytoplasmic region containing the catalytic domain. The extracellular domain of Axl has a unique structure that juxtaposes immunoglobulin and fibronectin Type III repeats and is reminiscent of the structure of neural cell adhesion molecules. Axl and its two close relatives, Mer/Nyk and Sky (Tyro3/Rse/Dtk), collectively known as the Tyro3 family of RTK's, all bind and are stimulated to varying degrees by the same ligand, Gas6 (growth arrest specific-6), a ˜76 kDa secreted protein with significant homology to the coagulation cascade regulator, Protein S. In addition to binding to ligands, the Axl extracellular domain has been shown to undergo homophilic interactions that mediate cell aggregation, suggesting that one important function of Axl may be to mediate cell-cell adhesion.

#Definitions

#As used in the specification and appended claims, unless specified to the contrary, the following terms have the meaning indicated:

#“Amino” refers to the —NH2 radical.