Compounds of formula (I): wherein X, L
1
, R
1
, L
2
, R
2
, R
3
, and R
4
are as defined herein, are useful in the treatment or prophylaxis of Duchenne muscular dystrophy, Becker muscular dystrophy, or cachexia.
式(I)的化合物:其中X,L1,R1,
L2,R2,R3和R4如本文所定义,在治疗或预防杜甫肌肉营养不良症、贝克尔肌肉营养不良症或消瘦症方面是有用的。