| abstract |
A novel compound has the following formula: <IMAGE> [I] in which R1 and R2 are methyl or a group having the formula: <IMAGE> [II] provided that one of R1 and R2 is methyl and the other is said group, wherein R stands for a hydrogen atom or a lower alkyl group, Z stands for a group <IMAGE> in which X1 and X2, which may be the same or different, stand for a hydrogen atom, a lower alkyl group, a lower alkoxy group, a trifluoromethyl group or a halogen atom, or a pyridyl group or a group <IMAGE> in which Y1 and Y2, which may be the same or different stand for a hydrogen atom, a lower alkyl group, a lower alkoxy group, a trifluoromethyl group or a halogen atom, X stands for a nitrogen or carbon atom, and n is an integer of from 2 to 10, provided that when R2 is the group having the formula II, X is not carbon and Z is not pyridyl. |