Abstract: A compound having the structural formula ##STR1## where R.sup.1 and R.sup.2 are the same or different and are hydrogen; however, both R.sup.1 and R.sup.2 cannot be hydrogen if R.sup.3 and R.sup.4 are both hydrogen or if one of R.sup.3 and R.sup.4 is hydrogen and the other nitro; in addition R.sup.1 and R.sup.2 may be the same or different and may be fluorine, chlorine, bromine, iodine, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.2 haloalkyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.7 -C.sub.9 aralkyl, phenyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 alkylthio, C.sub.1 -C.sub.6 alkylsulfinyl, C.sub.7 -C.sub.9 aralkoxy, phenoxy, provided that if both R.sup.3 and R.sup.4 are hydrogen, then R.sup.1 and R.sup.2 cannot be 3-phenoxy and hydrogen; also R.sup.1 and R.sup.2 may be the same or different and may be phenylthio, phenylsulfonyl, alkali metal carboxylate, C.sub.2 -C.sub.5 alkoxycarbonyl, phenoxycarbonyl or --NR.sup.5 R.sup.6 ; R.sup.3 and R.sup.4 are the same or different and are C.sub.1 -C.sub.