| abstract |
The present invention, the following general formula (1): wherein, X 1, X 2 is a different halogen atoms, R 1, R 2 are each the formula -OH, -OR 3, -OC (= O) -R 4 , Or -OC (= O) -NH-R 5 , R 1 and R 2 may be the same group or different groups, and R 3 , R 4 and R 5 are each a group of 1 to 18 carbon atoms An aromatic hydrocarbon group or an aliphatic hydrocarbon group having 1 to 18 carbon atoms, and R 3 , R 4 and R 5 may be the same or different groups.] |