Process for the preparation of 5-nitro-1,4-naphthoquinones
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)]
4278752
Alternative title(s) : (de) Verfahren zur herstellung von 5-nitro-1,4-naphthochinonen. (fr) Procédé de préparation de 5-nitro-1,4-naphtoquinone. (en) Process for the preparation of 5-nitro-1,4-naphthoquinone.
Patent number | Country code | Kind code | Date issued |
US4880571 | US | A | 1989-11-14 |
EP0221022 | EP | A3 | 1988-12-07 |
JPS62103044 | JP | A | 1987-05-13 |
EP0221022 | EP | A2 | 1987-05-06 |