. . . "A compound having the following formula ##STR15## wherein X is selected from the group consisting of H, alkoxy radicals and halogen, R1 is selected from the group consisting of H and alkyl radicals, provided that at least one of X and R1 is other than H, R2 is selected from the group consisting of methylene, substituted emthylene, ethylene, substituted ethylene, oxo, divalent oxyhydrocarbon radica" . .