Compounds and methods useful for stabilizing phenylalanine hydroxylase mutations

The disclosure relates to compounds of Formula I or a pharmaceutically acceptable salt thereof, wherein, m, R1-R5, R5A, and L are defined herein.These compounds are useful in methods for stabilizing a mutant PAH protein or reducing blood phenylalanine concentration in a subject suffering from phenylketonuria. In some embodiments, the mutant PAH protein contains at least one R408W, R261Q, R243Q, Y414C, L48S, A403V, I65T, R241C, L348V, R408Q, or V388M mutation. In other embodiments, the mutant PAH protein contains at least one R408W, Y414C, I65T, F39L, R408Q, L348V, R261Q, A300S, or L48S mutation.