The present invention relates to new CGRP-antagonists of general formula I wherein U, V, X, Y, R1, R2 and R3 are defined as stated hereinafter, the tautomers, the isomers, the diastereomers, the enantiomers, the hydrates, the mixtures thereof and the salts thereof and the hydrates of the salts, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, pharmaceutical compositions containing these compounds, their use and processes for preparing them.