Compounds of the formula ##STR00001## are inhibitors of protein tyrosine phosphatases (PTPases) and, thus, may be employed for the treatment of conditions mediated by PTPase activity. The compounds of the present invention may also be employed as inhibitors of other enzymes characterized with a phosphotyrosine binding region such as the SH2 domain. The compounds of formula (I) may be employed for prevention and/or treatment of insulin resistance associated with obesity, glucose intolerance, diabetes mellitus, hypertension and ischemic diseases of the large and small blood vessels, conditions that accompany type-2 diabetes, including hyperlipidemia, hypertriglyceridemia, atherosclerosis, vascular restenosis, irritable bowel syndrome, pancreatitis, adipose cell tumors and carcinomas such as liposarcoma, dyslipidemia, and other disorders where insulin resistance is indicated. In addition, the compounds of the present invention may be employed to treat and/or prevent cancer, osteoporosis, neurodegenerative and infectious diseases, and diseases involving inflammation and the immune system.