. . . . "tient an effective amount of a compound having the formula: [0029] where R1, R2, and R3 are the same or different and are a hydrogen, a nitro, a cyano, a carbamoyl, a halogen, a perfluoroalkyl, a haloalkylamido, an isothiocyanate, an azide, a diazocarbonyl, a substituted oxirane, or a ??-chloroethylamine; [0030] R4 is a hydrogen, an alkyl, or is joined to R5; [0031] R5 is a hydrogen, a hydroxy, an" .