Pyrido [2,1-a] isoquinoline derivatives

摘要

The present invention provides compounds of formula (I) wherein R<1>, R<2>, R<3 >and R<4 >are as indicated in the description, or a pharmaceutically acceptable salt thereof. The compounds are useful for the treatment of diseases which are associated with DPP-IV, such as diabetes, particularly non-insulin dependent diabetes mellitus, and impaired glucose tolerance.