The present invention relates to new CGRP-antagonists of general formula I wherein R1, R2, R3, Ra, Rb, Rc, X, Y and Z are defined as mentioned hereinafter, the individual diastereomers, the individual enantiomers and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, medicaments containing these compounds, the use thereof and processes for the preparation thereof.