A compound of the formula wherein R1, R2 and R3 are as defined above, which are inhibitors of the enzyme protein tyrosine kinases such as Janus Kinase 3 and as such are useful therapy as immunosuppressive agents for organ transplants, lupus, multiple sclerosis, rheumatoid arthritis, psoriasis, Type I diabetes and complications from diabetes, cancer, asthma, atopic dermatitis, autoimmune thyroid disorders, ulcerative colitis, Crohns disease, Alzheimers disease, Leukemia and other autoimmune diseases.