Design, Synthesis, and Anaplastic Lymphoma Kinase (ALK) Inhibitory Activity for a Novel Series of 2,4,8,22-Tetraazatetracyclo[14.3.1.13,7.19,13]docosa-1(20),3(22),4,6,9(21),10,12,16,18-nonaene Macrocycles

A novel set of 2,4,8,22-tetraazatetracyclo[14.3.1.1(3,7).1(9,13)]docosa-1(20),3(22),4,6,9(21),10,12,16,18-nonaene macrocycles were prepared as potential anaplastic lymphoma kinase (ALK) inhibitors, designed to rigidly lock an energy-minimized bioactive conformation of the diaminopyrimidine (DAP) scaffold, a well-documented kinase platform. From 13 analogues prepared, macrocycle 2m showed the most promising in vitro ALK enzymatic (IC50 = 0.5 nM) and cellular (IC50 = 10 nM) activities. In addition, macrocycle 2m exhibited a favorable kinase selectivity preference for inhibition of ALK relative to the highly homologous insulin receptor (IR) kinase (IR/ALK ratio of 173). The inclusive in vitro biological results for this set of macrocycles validate this scaffold as a viable kinase template and further corroborate recent DAP/ALK solid state studies indicating that the inverted U shaped conformation of the acyclic DAPs is a preferred bioactive conformation.