The present invention relates to compounds of formula I wherein R1, R2, R3, R4, and X are as defined herein or to pharmaceutically acceptable acid addition salts thereof, with the exception of 4-methoxy-N-[2-oxo-2-(phenylamino)ethyl]-N-phenyl-benzamide, 4-chloro-N-[2-[(4-methylphenyl)amino]-2-oxoethyl]-N-phenyl-benzamide, 4-chloro-N-[2-[5-chloro-2-methoxyphenyl)amino]-2-oxoethyl]-N-benzamide, 4-methyl-N-(2-oxo-2-[(2,4,6-trichlorophenyl)amino]ethyl]-N-benzamide, N-[2-[(4-methylphenyl)amino]-2-oxoethyl]-N-phenyl-benzamide, 4-methyl-N-[2-[(4-methylphenyl)amino]-2-oxoethyl]-N-phenyl-benzamide, 4-chloro-N-(2-oxo-2-[(2,4,6-trichlorophenyl)amino]ethyl]-N-benzamide and N-[2-[(2,4-dimethoxyphenyl)amino]-2-oxoethyl]-N-[(2-fluorophenyl)methyl]-benzeneacetamide. The compounds are useful in the treatment of neurological and neuropsychiatric disorders.
