| abstract |
The present invention provides a compound represented by formula (I): wherein R1 is a C1-6 alkyl group, optionally substituted with C3-10 cycloalkyl group, R2 is C2-6 alkyl group, R3 is hydrogen atom, a C1-6 alkyl group or a halogen atom, and X is -OR 6 or -NR 4 R 5, wherein R 4 and R 5 are each independently a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, R 5 is an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group or an optionally substituted hydroxy group, or R R5 optionally forms, together with the adjacent nitrogen atom, an optionally substituted nitrogen-containing heterocycle, or a salt thereof. The compound of the invention has a superior peptidase inhibitory activity and is useful as a means of prophylaxis or treatment of diabetes and the like. |