Patent ID: 8163907

Claim:
A compound of a general formula (I) or a pharmaceutical salt thereof: wherein R 1 represents a substituted or unsubstituted heterocyclic, aromatic ring or aralkyl group, and a substituent is selected from the collection of a C 1 -C 4 alkyl group, a C 1 -C 4 alkoxyl group, a halogen, a cyano-group, a trifluoromethyl group, a trifluoromethoxyl group, a methylthio group, a nitro group, an amino group and a hydroxyl group, R 2 represents a C 1 -C 8 alkyl group selected from the collection of an alkyl group having a hydroxyl group or a C 1 -C 6 alkoxyl substituent, R 3 and R 4 are the same or different, and independently represent hydrogen, halogen, a cyano-group, a trifluoromethyl group, a trifluoromethoxyl group, a methylthio group, a nitro group, an amino group, a C 1 -C 4 an alkyl group, a C 1 -C 4 alkoxyl group, a C 1 -C 4 alkenyl group or a C 1 -C 4 alkinyl group, R 5 and R 6 are the same or different and represent a C 1 -C 4 alkyl group selected from the collection of an alkyl group having a hydroxyl group and a C 1 -C 4 alkoxyl substituent, X represents O, S or a single bond, m=0-6, n=1-6, and m and n are the same or different.