PIPERAZINE DERIVATIVES AND USE OF THE SAME

摘要

Compounds represented by general formula (I) or salts thereof and a process for producing the same wherein R<1> represents carboxy or carboxamide; R<2> represents hydrogen or lower alkyl, or R<2> may be bonded to R<3> or R<4> to thereby form a ring; R<3> and R<4> represent each hydrogen, lower alkyl or sulfide, or R<3> and R<4> may be bonded to each other to thereby form a ring; R<5> represents substituted phenyl or substituted sulfonyl represented by general formula (III): -SO2-R<7> (wherein R<7> represents aryl or amino); and n is 0 or 1. Because of having the effect of inhibiting cysteine protease, the compounds are useful as a preventive or remedy for various diseases in which cysteine protease participates, for example, ischemic diseases, inflammation, muscular dystrophy, immunologic diseases, essential hypertension, Alzheimer's disease, subarachnoidal bleeding, osteoporosis, etc.