A compound of Formula I, enantiomers, diasteriomers, tautomers or pharmaceutically acceptable salts thereof, wherein R 1 , R 2 and R 3 are defined herein, are useful as inhibitors of one or more Janus kinases. A pharmaceutical composition that includes a compound of Formula I and a pharmaceutically acceptable carrier, adjuvant or vehicle, and methods of treating or lessening the severity of a disease or condition responsive to the inhibition of a Janus kinase activity in a patient are disclosed.
