The invention relates to novel acylamino-hydroxy-benzamides of formula (I), wherein R
1
is phenyl substituted by phenyl, phenoxy, phenylamino or heteroaryl, all optionally further substituted; bicyclic aryl, monocyclic heteroaryl substituted by optionally substituted phenyl, or bicyclic heteroaryl, R
2
is hydrogen or methyl, and R
3
and R
4
have the meanings indicated in the description. These compounds are useful for the treatment and/or prophylaxis of skeletal muscle atrophy, schizophrenia and Alzheimer's disease, and as cognitive enhancers.