Xanthine derivatives, their preparation and their use in pharmaceutical compositions

摘要

Compounds of formula (I) wherein R<1 >to R<4 >are defined as in the claims, or the prodrugs or salts thereof, particularly the physiologically acceptable salts thereof, pharmaceutical compositions containing these compounds, and methods of treating type I and type II diabetes mellitus, arthritis, obesity, allograft transplantation, or calcitonin-induced osteoporosis using these compounds.