Abstract: Compounds of the formula provide pharmacological agents which are inhibitors of PTPases, in particular, the compounds of formula I inhibit PTP-1B and TC PTP, and thus may be employed for the treatment of conditions associated with PTPase activity. The compounds of the present invention may also be employed for inhibition of other enzymes with a phosphotyrosine binding region such as the SH2 domain. Accordingly, the compounds of formula I may be employed for prevention or treatment of insulin resistance associated with obesity, glucose intolerance, diabetes mellitus, hypertension and ischemic diseases of the large and small blood vessels.