Title compds. I (R = H, C1-4 alkyl or alkoxy), useful as dye intermediates, are prepd. by oxidn. of nitronaphthalenes with Mn2(SO4)3. A melt contg. 173 parts 1-nitronaphthalene was treated over 30 min with 2200 parts of an aq. 36% Mn2(SO4)3-H2SO4 soln. which contained 0.9% Ce2(SO4)3. The mixt. was stirred at 60 Deg and after work-up gave .apprx.55% I (R = H) of 90-95% purity. [on SciFinder (R)]