R1's and R2's are each independently a hydrogen atom, a deuterium atom, a halogen atom, or a group selected from the group consisting of an alkyl group, an aryl group, an alkoxyl group and an amino group which may be substituted or unsubstituted; and R3 is a deuterium atom, a halogen atom, or a group selected from the group consisting of an alkyl group and an alkoxyl group which may be substituted