. . . . . . . . "substituent selected from a group consisting of hydrogen, hydroxyl, C1-C6 alkyl, C1-C6 alkylamino, halogen, C1-C6 alkoxy, ???NO2, ???NH2, and ???C???N; and R3 is a substituent selected from a group consisting of an aryl, a substituted aryl, a heterocycle, a heteroaryl, a substituted heterocycle, and a substituted heteroaryl. 58." . .