Disclosed is a compound of formula I or a pharmaceutically acceptable salt thereof wherein A is phenyl； R1 is up to two substituents independently selected from chloro, isopropoxy, and cyano； R2 is hydrogen or methyl； B is a piperidyl ring； R3 is hydrogen, methyl or (CH2)1-3CO2H and R4 is hydrogen. Specific examples of formula I include 5-(5-{ 3-chloro-4-[(1-methylethyl)oxy]phenyl} -1,2,4-oxadiazol-3-yl)-1,2,3,4-tetrahydroisoquinoline 2-[(1-methylethyl)oxy]-5-[3-(1,2,3,4-tetrahydro-5-isoquinolinyl)-1,2,4-oxadiazol-5-yl]benzonitrile [5-(5-{ 3-cyano-4-[(1-methylethyl)oxy]phenyl} -1 ,2 ,4-oxadiazol-3-yl)-3,4-dihydro-2(1H)isoquinolinyl]acetic acid Also disclosed is the use of the compound in the manufacture of a medicament for use in the treatment of conditions or disorders mediated by S1P1 receptors, such as multiple sclerosis, autoimmune diseases, chronic inflammatory disorders, asthma, inflammatory neuropathies, arthritis, transplantation, Crohn's disease, ulcerative colitis, lupus erythematosis, psoriasis, ischemia-reperfusion injury, solid tumours, and tumour metastasis, diseases associated with angiogenesis, vascular diseases, pain conditions, acute viral diseases, inflammatory bowel conditions, insulin and non-insulin dependant diabetes.
