2-Amino-8-nitronaphthalene

Amino-4-nitronaphthalene [776-34-1] M 188.2, m 195°, pK 0.54. Crystd from EtOH or ethyl acetate. 

I, 4-benzoquinone.4 Other methods that have been employed include the oxidation of naphthalene with hydrogen peroxide,5 the oxidation of 1,4-naphthalenediamine 6 and naphthylamine sulfonic acid 7 and the oxidation of 4-amino-1-naphthol prepared by electrolytic reduction of 1-nitronaphthalene.8... 

The reduction to produce azoxy compounds appears to be successful for a wide range of aromatic nitro compounds. The following compounds, however, could not be reduced 1-nitronaphthalene, m-dinitrobenzene, 3,5-dinitroben-zoic acid (although o-, m-, and p-nitrobenzoic acids were reduced smoothly), compounds containing an amino group o-, orp- to a nitro group (except sodium... 

Sulfurous acid and its salts are inexpensive reducing agents which are, however, usable only in special cases. These reagents frequently give sulfonation simultaneously with reduction (cf. the preparation of l-naphthylamine-2,4-disulfonic acid from 1-nitronaphthalene, and of l-amino-2-naphthol-4-sulfonic acid from nitroso- -naphthol, pages 178 and 201). Also, in the reduction of diazobenzene to phenylhydrazine, a N-sulfonic acid is formed first and this must be split by vigorous treatment with hydrochloric acid (see pages 96 and 128). 

Most of the isomeric Al-aminonaphthotriazoles have been described. Direct amination of naphtho[ 1,2-(/]triazole gives its 3-amino (142) and 2-amino (143) derivatives in yields of 24% and 23%, respectively [67JCS(C)1276]. However, on repeating the experiment, the yield of amines was worse (18% and 3%, respectively) [69JCS(C)756]. Traces of the uncharacterized 1-amino derivatives were found in the mixture. 3-Aminonaphtho[l,2-t/]triazole was also obtained in several steps from 2-amino-1 -nitronaphthalene [67JCS(C) 1276]. 

Aromatic nitro compounds are comparable with pyridine derivatives in reactivity and can sometimes be aminated directly. l-(4 -Nitro-l -naphthyl)-piperidine was obtained from 1-nitronaphthalene and sodium piperidide (sodamide and piperidine).396 Nitrobenzene and the alkali derivative of carbazole397 or diphenylamine398 gave the corresponding /7-amino derivative, 9-(/7-nitrophenyl)carbazole (70%) and 4-nitrotriphenylamine (45%). Huisgen and Rist399 record the reaction of nitrobenzene with lithium piperidide. 

Amination of aromatic nitro compounds often occurs smoothly and directly also on condensation with hydroxylamine in alkaline solution, the amino group normally entering ortho or para to the nitro group. One nitro group activates naphthalene derivatives sufficiently, but in the benzene series two are necessary to induce this reaction. 2-Nitro-l-naphthylamine was thus obtained (80%) from 2-nitronaphthalene,400 and 4-nitro-l-naphthyl-amine (60%) from 1-nitronaphthylamine.401 The amino group also enters the nitrated ring of quinoline derivatives. 

Alkylation and reduction of the nitro group to the amino has been observed in the methyl ether of 4-hydroxy-nitronaphthalene. Cydohexylmagnesium chloride in tetrahydrofuran added dropwise but rapidly at 0°C to the compound in tetrahydrofuran followed successively by tert-butanol and phosphorus trichloride in tetrahydrofuran with completion of the reactton at ambient temperarure during 3 hours gave after acidification with hydrochloric acid,... 

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