5-membered heterocyclic compounds, processes for preparing them and pharmaceutical compositions containing these compounds

摘要

Compounds of the formula <IMAGE> (I) wherein X1 to X5 are as defined herein, the tautomers, the stereoisomers including the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases. The compounds are useful for inhibiting undesirable cell aggregation.