4-(4-chlorophenoxyacetyl)piperazinyl; (2) R4 is an unsubstituted alkyl group, preferably methyl; R5 is ???H or an unsubstituted alkyl group, preferably ???H or methyl; (4) R1 is an unsubstituted alkyl group, preferably ethyl; and (5) at least one of R2 and R3 is a group that enhances water solubility, ???OCF3, ???NO2 and/or a halogen.