摘要 |
The present invention relates to compounds of formula (I) wherein R<SUP>1 </SUP>to R<SUP>4 </SUP>are as defined in the description and claims, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prophylaxis of diseases which are associated with DPP-IV, such as diabetes, particularly non-insulin dependent diabetes mellitus, and impaired glucose tolerance. |