The invention relates to phenylpropionamide compounds of Formula I: and pharmaceutically acceptable salts, prodrugs, and solvates thereof, wherein A, B, R 1 , R 2 , R 3 , R 4 and R 5 are defined as set forth in the specification. The invention is also directed to the use of compounds of Formula I to treat, prevent or ameliorate a disorder responsive to the activation of opioid receptors, particularly µ-opioid receptors. Compounds of the present invention are especially useful for treating pain.
