abstract |
Compounds of formula I: n nwherein R 1 , R 2 , R 3 , R 4 and n have any of the values defined in the specification, and their pharmaceutically acceptable salts, are useful for inhibiting β-lactamase enzymes, for enhancing the activity of β-lactam antibiotics, and for treating β-lactam resistant bacterial infections in a mammal. The invention also provides pharmaceutical compositions, processes for preparing compounds of formula I, and novel intermediates useful for the synthesis of compounds of formula I. |