Recent Enamine’s paper disclosed novel heteroaryl difluoroacetates and the corresponding carboxylic acids, amides, nitriles and alcohols as promising building block in drug design. Known literature example of metabolism-directed optimization of 3-aminopyrazinone acetamide thrombin inhibitor 1 led to the the corresponding 2,2-difluoro-2-pyridin-2-yl derivative 2, which is not prone to metabolic oxidation at the α-methylene group next to the aromatic moiety.
