Provided are phenyl-3-aza-bicyclo[3.1.0]hex-3-yl-methanone derivative compounds of general formula (I), wherein the variables are as described in the specification. Examples of the compounds include [5-Methanesulfonyl-2-(2,2,2-trifluoro-1-methyl-ethoxy)-phenyl]-[1-(5-trifluoromethyl-[1,2,4]oxadiazol-3-yl)-3-aza-bicyclo[3.1.0]hex-3-yl]-methanone and [5-Methanesulfonyl-2-(2,2,2-trifluoro-1-methyl-ethoxy) phenyl]-{ 1-[5-(3-methyl-oxetan-3-yl)-[1,2,4]oxadiazol-3-yl]-3-aza-bicyclo[3.1.0]hex-3-yl} -methanone. The compounds are glycine transporter-1 (GlyT1) inhibitors. The compounds may be useful in the treatment of the positive and negative symptoms of schizophrenia as well as cognitive impairments associated with schizophrenia, Alzheimer&rsquo；s disease and other neurological and psychiatric disorders.
