Piperidine inhibitors of janus kinase 3

1. A method of treatment of a disorder selected from the group consisting of renal transplant rejection, rheumatoid arthritis, psoriasis, inflammatory bowel disease, dry eye syndrome, asthma, and transplant rejection comprising the administration, to a patient in need thereof, of a therapeutically effective amount of a compound having the structural formula

or a pharmaceutically acceptable salt thereof.

2. The method as recited in claim 1 wherein said disorder is rheumatoid arthritis.