Patent ID: 7365096

Claim:
An in vitro method of suppressing Janus tyrosine kinase 3 (Jak3)-dependent proliferation of a cell expressing Janus tyrosine kinase 3, comprising: selectively targeting Jak3 activity in the cell for inhibition by contacting the cell with at least one compound of the formula (I) wherein R 1 is H, ═CH 2 , CH 2 N(CH 3 ) 2 , CH 2 SC(O)CH 3 , CH 2 SC 6 H 5 , CH 2 SCH 2 -(4-C 6 H 4 OCH 3 ), CH 2 SC(O)C 6 H 5 or CH 2 N(CH 2 CH 3 ) 2 ; R 2 is O; R 3 is CH 2 N(CH 3 ) 2 , CH 2 N(CH 2 CH 3 ) 2 or CH 2 —(N-morphyl); or a salt thereof, at a concentration effective to selectively inhibit Janus tyrosine kinase 3 activity, whereby Jak3-dependent proliferation of the cell is suppressed.