SUBSTITUTED PYRIDO [1,2-a] ISOQUINOLINE DERIVATIVES

摘要

The present invention relates to compounds of formula (I) wherein R1 to R4 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.