摘要 |
The present invention provides compounds of formula (I) wherein R<SUP>1</SUP>, R<SUP>2</SUP>, R<SUP>3 </SUP>and R<SUP>4 </SUP>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. |