A compound represented by the following general formula (I) or a pharmacologically acceptable salt thereof, wherein R 1 represents a C1 to C6 alkyl group which may be substituted by one to three groups selected from substituent group A, or the like (substituent group A: a hydroxy group, a halogeno group, a cyano group, a nitro group, an amino group, a carboxy group, a C1 to C3 alkyl group, etc.)； R 2 , R 3 , and R 8 each independently represent a hydrogen atom or a C1 to C3 alkyl group； R 4 , R 5 , R 6 , R 7 , R 9 , and R 10 each independently represent a hydrogen atom or the like； and R 11 represents a hydrogen atom or the like, has TAFIa enzyme inhibitory activity and is useful as a therapeutic drug for myocardial infarction, angina pectoris, acute coronary syndrome, cerebral infarction, deep vein thrombosis, pulmonary embolism, or the like.
