The invention is related to compounds of general formula (I) ##STR1## wherein R is methyl, ethyl, n-propyl, iso-propyl, n-butyl or allyl; R' is methyl, methoxy, fluoro, chloro, bromo, azido, trifluorometlhyl, or OCH.sub.x F.sub.y, wherein x=0-2, y=1-3 with the. proviso that x+y=3; R" is hydrogen, fluoro or chloro; with the proviso that R" is fluoro or chloro only when R' is fluoro or chloro; R.sub.4 is hydrogen or pharmaceutically acceptable inorganic or organic cations; R.sub.5 is dimethylamino or nitro; R.sub.6 is hydrogen; and when R' is azido R.sub.5 is also ethyl, n-propyl, iso-propyl, methoxy, ethoxy, chloro, bromo, trifluoromethyl, OCH.sub.x F.sub.y, wherein x=0-2, y=1-3 with the proviso that x+y=3, or R.sub.5 and R.sub.6 taken together are methylenedioxy; and any tautomer thereof. The invention also relates to pharmaceutical compositions containing a compound of the general formula (I) together with a pharmaceutically acceptable carrier. Included are also processes for the preparation of the compounds of formula (I), as well as methods for the treatment of mammals suffering from diseases resulting from autoimmunity and pathological inflammation by administering of a compound having the formula (I) to said mammal.