The invention relates to compounds of the general formula (I) wherein R.sup.1, R.sup.2, R.sup.3, Ar, and X are as defined herein, or a pharmaceutically acceptable salt, hydrates, geometrical isomers, racemates, tautomers, optical isomers, N-oxides and prodrug forms thereof. The compounds may be used for the treatment or prophylaxis of disorders related to the MCH1R receptor and for modulation of appetite. The invention also relates to such use as well as to pharmaceutical formulations comprising a compound of formula (I).