Therapeutic agent for cerebral infarction

A piperazine compound represented by formula <2>

• wherein
• R1 and R2 are the same or different and each is hydrogen, halogen, lower alkyl, lower alkoxy, amino, nitro, hydroxyl, cyano or amino which is mono- or di-substituted by at least one functional group selected from the group consisting of lower alkyl and lower acyl,
• R3, R4 and R5 are the same or different and each is hydrogen, halogen, lower alkyl, lower alkoxy, nitro, amino, hydrocyano or amino which is mono- or di-substituted by at least one functional group selected from the group consisting of lower alkyl and lower acyl,
• R6 and R7 are the same or different and each is hydrogen, lower alkyl, lower alkyl substituted by 1 to 3 halogens, aralkyl, acyl or lower acyl substituted by 1 to 3 halogens,
• R8 and R9 are the same or different and each is hydrogen or lower alkyl,
• Ra-Rd are the same or different and each is hydrogen, lower alkyl, aralkyl or hydroxy lower alkyl, or any two of Ra-Rd are bonded to each other to form alkylene having a carbon number of 1-2,
• Y is a group represented by formula
• wherein
• R10 and R11 are the same or different and each is hydrogen or lower alkyl,
• R12 and R13 are the same or different and each is hydrogen or lower alkyl, or R12 and R13 are groups that form alkylene in combination,
• R14 and R15 are the same or different and each is hydrogen or lower alkyl,
• m is an integer of 0-2, n is an integer of 0-2, and 0≦m+n≦2,
• ring A is phenyl, pyrimidyl, thiazolyl, pyridyl, pyrazinyl or imidazolyl, and
• ring B1 is pyridyl or thienyl,
• or a pharmaceutically acceptable salt thereof.

A method of treating a cerebral infarction, the method comprising:

• administering to a subject in need thereof an effective amount of a piperazine compound represented by formula <1>
• wherein
• R1 and R2 are the same or different and each is hydrogen, halogen, lower alkyl, lower alkoxy, amino, nitro, hydroxyl, cyano or amino which is mono- or di-substituted by at least one functional group selected from the group consisting of lower alkyl and lower acyl,
• R3, R4 and R5 are the same or different and each is hydrogen, halogen, lower alkyl, lower alkoxy, nitro, amino, hydroxyl, cyano or amino which is mono- or di-substituted by at least one functional group selected from the group consisting of lower alkyl and lower acyl,
• R6 and R7 are the same or different and each is hydrogen, lower alkyl, lower alkyl substituted by 1 to 3 halogens, aralkyl, acyl or lower acyl substituted by 1 to 3 halogens,
• R8, R9 are the same or different and each is hydrogen or lower alkyl,
• Ra-Rd are the same or different and each is hydrogen, lower alkyl, aralkyl or hydroxy lower alkyl, or any two of Ra-Rd are bonded to each other to form alkylene having a carbon number of 1 or 2,
• Y is a group represented by the formula
• wherein
• R10 and R11 are the same or different and each is hydrogen or lower alkyl,
• R12 and R13 are the same or different and each is hydrogen or lower alkyl, or R12 and R13 are groups that form alkylene in combination,
• R14 and R15 are the same or different and each is hydrogen or lower alkyl, and
• m is an integer of 0-2, n is an integer of 0-2 and 0≦m+n≦2,
• ring A is phenyl, pyrimidyl, thiazolyl, pyridyl, pyrazinyl or imidazolyl, and
• ring B is pyridyl or thienyl,
• or a pharmaceutically acceptable salt thereof.