Cartoon representation of the binding pocket of JAK3 with compound 39 (a) and 45 (b). In 39, dipyrrolopyridine moiety develops hydrogen bonds to the GLU 903 and LEU 905 of the hinge region while its furanamide moiety interacts with ARG 953 from the lower lobe and ASN 832 from the upper lobe. In compound 45, dipyrrolopyridine moiety develops hydrogen bonds to the GLU 903 and LEU 905 hinge residue while its furanamide moiety makes a bidentate hydrogen bond to the LYS 855 and develops many other interactions with residues from the upper and lower lobe. Hydrogen bonding is represented by dotted lines. All the interacting residues are shown in the line model.