SAR and in vivo evaluation of 4-aryl-2-aminoalkylpyrimidines as potent and selective Janus kinase 2 (JAK2) inhibitors.

We report the discovery of a series of 4-aryl-2-aminoalkylpyrimidine derivatives as potent and selective JAK2 inhibitors. High throughput screening of our in-house compound library led to the identification of hit 1, from which optimization resulted in the discovery of highly potent and selective JAK2 inhibitors. Advanced lead 10d demonstrated a significant dose-dependent pharmacodynamic and antitumor effect in a mouse xenograft model. Based upon the desirable profile of 10d (XL019) it was advanced into clinical trials.