Discovery of 5-Amino-N-(1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide Inhibitors of IRAK4

ACS Med Chem Lett. 2015 Apr 20;6(6):683-8. doi: 10.1021/acsmedchemlett.5b00107. eCollection 2015 Jun 11.


Interleukin-1 receptor associated kinase 4 (IRAK4) is an essential signal transducer downstream of the IL-1R and TLR superfamily, and selective inhibition of the kinase activity of the protein represents an attractive target for the treatment of inflammatory diseases. A series of 5-amino-N-(1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamides was developed via sequential modifications to the 5-position of the pyrazolopyrimidine ring and the 3-position of the pyrazole ring. Replacement of substituents responsible for poor permeability and improvement of physical properties guided by cLogD led to the identification of IRAK4 inhibitors with excellent potency, kinase selectivity, and pharmacokinetic properties suitable for oral dosing.

Keywords: 5-amino-N-(1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide; IRAK4; SAR; inflammatory disease; kinase inhibitor; serine-threonine kinase.