The present invention relates to the CGRP-antagonists of general formula I ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and X are defined as in claim 1, the tautomers, the isomers, the diastereomers, the enantiomers, the hydrates, mixtures and salts thereof and the hydrates of the salts, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, as well as those compounds of general formula I in which one or more hydrogen atoms are replaced by deuterium, pharmaceutical compositions containing these compounds, the use thereof and processes for the preparation thereof.