A compound of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, which are inhibitors of the enzyme protein kinases such as Janus Kinase 3 and as such are useful therapy as immunosuppressive agents for organ transplants, xeno transplation, lupus, multiple sclerosis, rheumatoid arthritis, psoriasis, Type I diabetes and complications from diabetes, cancer, asthma, atopic dermatitis, autoimmune thyroid disorders, ulcerative colitis, Crohn's disease, Alzheimer's disease, Leukemia and other autoimmune diseases.