4- Nitro-l-naphthol

Nitro-l-naphthol, see Naphthalene Nitrophenol, see Benzene, Toluene 2-Nitrophenol, see Benzene. Nitrobenzene, Phenol... 

Nitration of arenes. Reaction of 1-naphthol with CAN in acetic acid results in 2,4- and 4,6-dinitro derivatives. The reaction with CAN absorbed on silica gel results in 2-nitro- and 4-nitro-l-naphthol in 42 and 38% yield, respectively. Polynuclear arenes are not oxidized to quinones by CAN supported on silica but are converted mainly into mononitro derivatives. Thus phenanthrene is converted into 2-nitrophenanthrene (45% yield) and 3-nitrophenanthrene (28% yield).1... 

A bicyclic aromatic ring system provides additional stabilization of the anionic a-adducts hence, nitronaphthalene derivatives show good reactivity in the VNS hydroxylation. 1-Nitronaphthalenes give 2- and 4-hydroxy derivatives in high yields. The orientation of the hydroxylation depends on the kind of base. For instance, treatment of 1-nitronaphthalene (15) with f-butyl hydroperoxide and potassium t-butoxide affords l-nitro-2-naphthol (16) whereas using sodium hydroxide as base gives 4-nitro-l-naphthol (14) (equation 34) . 

Can be coupled in the 4-position with dia-zotized bases to give a series of azo dyestuffs more usually it is first sulphonated to give a valuable series of intermediates for solubilized azo dyestuffs. The nitro-l-naphthols are themselves dyestuffs, e.g. 2,4-dinitro-l-naph-thol ( naphtol yellow ). 

Naphthalenol also is used ia the preparation of azo, iadigoid, and nitro, eg, 2,4-dinitro-l-naphthol, dyes, and ia making dye iatermediates, eg, naphtholsulfonic acids, 4-chloro-1-naphthalenol, and l-hydroxy-2-naphthoic acid. 1-Naphthalenol is an antioxidant for gasoline, and some of its alkylated derivatives are stabilizers for plastics and mbber (68). 

Nitro-4-lodo-1-Oxy-Naphthalene (2-Nitro-4-iodo-l-naphthol). (02N)C1oHs(I).OH, mw 315.09, N 4.45%, OB to C02 -101.56%, clear golden needles, mp 115° (decompn). Prepn from 4-nitro-2-acetoxymercuric-naphthol-(l) by reacting with iodine... 

Tri nitro-1 -N aphthol (2,4,7 -Trinitro-1 -oxy-naphthalene). Yellow prisms from AcOH or benz, mp 145° (decompn). Sol in AcOH glac AcOH. Prepn from 2,4-dinitro-l-naphthol by mixed acid (nitric-sulfuric-acetic) nitration. The compound is extracted as the Na salt from... 

X,X,X-Tetranitro-1 -Naphthol (4,X,X,X-Tetranitro-l-oxy-naphthalene). Yellow needles from ale, mp 215°. Prepn from 4-nitro-l-ethoxy naphthalene by nitration Ref Beil 6, 621... 

Synthesis of DBA 3,4-dihydrodiol from DBA 3,4-dione via bro-mination and reduction of the 1,2-dibromo compound with sodium bo-rohydride has also been described (44). The DBA 3,4-dione was synthesized by Kundu from 5-bromo-2-nitro-l-naphthol in nine steps in 4.2% overall yield (45). More recently, reduction of DBA 3,4-dione with NaBH, in the presence of air has been reported to afford directly the 3,4-dihydrodiol (22). 

N(—> N N.Cj0H6.OH purple-red crysts, mp 228° sol in ale, glac acet ac. eth acet si sol in benz chlf forms a K sait, KCi6H10N3O4, green + bronze luster crysts (from ale), which explodes on heating (Refs 1 5) 4-Nitro-l-hydroxybenzene-(3 azo D-2-naphthol,... 

Nitro-l-dictzo-2-napbtbol [called 4-Nitro-l -diazo-naphthol-(2) or 4-Nitro-naphthochinon (l 2)-diazid-(l) in Get], yel ndLs (from petr eth), mp 130-34° (dec) readily sol in acet, glacial acet acid St benz mod sol in ale si sol in w was prepd by diazotizing 2,4-dinitro-1-n aphthy lamin e (Refs 1, 4 St 6) J-Nitro-l-diazo-2-napbthol, crysts (from diox-ane), mp 160-62°(dec) was obtd when the 2, 7-dinitro-l-naphthylamine diazotized salt was poured into water contg Na acetate (Ref 8) Refs 1) Beil 16, 533 2) Beil 16, (365)... 

C22H13N707, mw 487.38, N 20.12% dk crysts (from benz or acet+w), mp 265- 5 mod sol in benz or toluene si sol in anisole or acet diffc sol in ale insol in alkalies dissolves in in coned H2S04 giving a green color was prepd by treating 4-nitrobenzene-5 -nitro-l-naphthol in ale soln with 4-nitro-benzene-l-diazoniumchloride. Its expl props were not investigated... 

To a mixture of 103 grams of 62 per cent nitric acid (40° B6) and 300 grams of 80 per cent sulfuric acid, 128 grams of naphthalene is added. The mixture is stirred continuously for 6 hours at 50°C., and then the temperature is raised to 60° during the course of 1 hour. On cooling the mixture, the nitronaphthalene floats as a porous cake on the surface of the acid. It contains about 90 to 92 per cent of the o-nitro compound, 4 to 5 per cent of the j3-nitronaphthalene, 2 to 3 per cent of dinitronaphthalene, and about 0.5 per cent of 2,4-dinitro-l-naphthol (Martins yellow). 

Nitro-4 diazo-l naphthol (called 2-Nitro-4-dia2otiaphthalene l-oxide by Hodgson Sc Smith), pale-yel ndls (from ale), mp 163°... 

Nitro-l-diazo-2-naphthol [called 4-Nitro-i -diazo-naphthol (2) or 4-Nitro-naphthochinon... 

Reeves and co-workers [76] correlated the change in the chemical shift of NMR spectra caused by formation of an intramolecular hydrogen bond in o- ubstituted phenols including o-nitrophenol, 2,4-dinitrophenol, I-nitro-2-naphthol, 2,4-dinitro-l-naphthol etc. 

Hodgson and Smith found that with use of just 3 equivalents of stannous chloride 2,4-dinitro-l-naphthol can be reduced selectively to 2-nitro-4-amino-l-napthol. A suspension of the dinitro compound in coned, hydrochloric acid and ethanol was OH... 

Note that in the partial reduction of 2,4-dinitro-l-naphthol with alcoholic stannous chloride to 2-nitro-4-amino-l-naphthol6 the nitro group selectively reduced is not that ortho to the hydroxyl group but that in the reactive a-position of the naphthalene nucleus. 

Benzotropolones take part in electrophilic substitution reactions, for example halogenation [293,328,331] and coupling with aryldiazonium salts [332]. They may undergo rearrangement to benzenoid compounds in some instances, for example treatment of 3,4-benzotropolone with excess bromine gives 2,3-dibromonaphtho-quinone and with excess concentrated nitric acid leads to 2,4-di-nitro-l-naphthol [333]. Like other tropolones, 3,4-benzotropolone is photochemically converted into a bicycloheptadienone [334]... 

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