ATR is an attractive new anticancer drug target whose inhibitors have potential as chemo- or radiation sensitizers or as monotherapy in tumors addicted to particular DNA-repair pathways. We describe the discovery and synthesis of a series of sulfonylmorpholinopyrimidines that show potent and selective ATR inhibition. Optimization from a high quality screening hit within tight SAR space led to compound 6 (AZ20) which inhibits ATR immunoprecipitated from HeLa nuclear extracts with an IC50 of 5 nM and ATR mediated phosphorylation of Chk1 in HT29 colorectal adenocarcinoma tumor cells with an IC50 of 50 nM. Compound 6 potently inhibits the growth of LoVo colorectal adenocarcinoma tumor cells in vitro and has high free exposure in mouse following moderate oral doses. At well tolerated doses 6 leads to significant growth inhibition of LoVo xenografts grown in nude mice. Compound 6 is a useful compound to explore ATR pharmacology in vivo.
I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high‐yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert‐butoxycarbonyl, EWG=electron‐withdrawing group, Ns=4‐nitrobenzenesulfonyl, Ts=4‐toluenesulfonyl.
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