Abstract: Compounds of formula (I) and salts and solvates are provided: wherein R2 is selected from phenyl substituted with n R1 groups, and pyridyl substituted with n R1 groups; n=0, 1 or 2; each R1 is independently selected from the group consisting of halo, C1-4alkyl, C1-4alkoxy, haloC1-4alkyl, haloC1-4alkoxy and cyano; R3 is selected from hydrogen and C1-2 alkyl; R4 is selected from the group consisting of ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl; or R3 and R4 together with the nitrogen atom to which they are attached form a saturated 5- or 6-membered heterocyclic ring optionally substituted with one or more groups X; each X is independently selected from the group consisting of C1-4alkyl, and haloC1-4alkyl; R12 is selected from the group consisting of hydrogen, fluoro, chloro, bromo, methyl and methylthio; R13 is selected from hydrogen, chloro and trifluoromethyl; R14 is selected from hydrogen, trifluoromethyl and chloro; R15 is selected from hydrogen, chloro and trifluoromethyl; R16 is selected

Abstract: The invention provides a compound of formula (I) or a salt or solvate thereof: wherein R1, n, X, Y and Z are as defined in the specification, and uses of such compounds. The compounds inhibit GlyT1 transporters and are useful in the treatment of certain neurological and neuropsychiatric disorders, including schizophrenia.