2- Nitronaphthalene preparation

Colourless crystals m.p. 50 C, b.p. 301 C. Basic and forms sparingly soluble salts with mineral acids. Prepared by the reduction of 1-nitronaphthalene with iron and a trace of hydrochloric acid or by the action of ammonia upon l-naphlhol at a high temperature and pressure. 

Naphthaleneamine. 1-Naphthylamine or a-naphth5iamine/7i5 -i2- can be made from 1-nitronaphthalene by reduction with iron—dilute HCl, or by catalytic hydrogenation it is purified by distillation and the content of 2-naphthylamine can be reduced as low as 8—10 ppm. Electroreduction of 1-nitronaphthalene to 1-naphthylamine using titania—titanium composite electrode has been described (43). Photoinduced reduction of 1-nitronaphthalene on semiconductor (eg, anatase) particles produces 1-naphthylamine in 77% yield (44). 1-Naphthylamine/7J4-J2-. can also be prepared by treating 1-naphthol with NH in the presence of a catalyst at elevated temperature. The sanitary working conditions are improved by gas-phase reaction at... 

H-acid, l-hydroxy-3,6,8-ttisulfonic acid, which is one of the most important letter acids, is prepared as naphthalene is sulfonated with sulfuric acid to ttisulfonic acid. The product is then nitrated and neutralized with lime to produce the calcium salt of l-nitronaphthalene-3,6,8-ttisulfonic acid, which is then reduced to T-acid (Koch acid) with Fe and HCl modem processes use continuous catalytical hydrogenation with Ni catalyst. Hydrogenation has been performed in aqueous medium in the presence of Raney nickel or Raney Ni—Fe catalyst with a low catalyst consumption and better yield (51). Fusion of the T-acid with sodium hydroxide and neutralization with sulfuric acid yields H-acid. Azo dyes such as Direct Blue 15 [2429-74-5] (17) and Acid... 

Tetranitronaphthalene was prepared by adding nitric acid/sulphuric acid mixture to 1-nitronaphthalene. A solid residue formed after a valve had broken down. The medium was heated to try to melt the residue. This operation gives rise to a precipitate present in large quantities that blocked the stirrer and caused the reactor to detonate violently. 

Prepare a mixtime of 40 ml. of concentrated nitric acid and 40 ml. of concentrated sulphiu-ic acid as detailed in the previous Section. Introduce 50 g. of findy-powdered naphthalene in small quantities at a time and with vigorous shaking maintain the temperatime at 45-50° and cool in ice water if necessary. When all the naphthalene has been added, warm the mixtime on a water bath at 55-60° for 30-40 minutes or until the smell of naphthalene has disappeared. Pour the mixture into 500 ml. of cold water the nitronaphthalene will sink to the bottom. Decant the liquid. Boil the solid cake with 200 ml. of water for 20 minutes and pour the water away. Transfer the oil to a large flask and subject it to steam distillation (Fig. II, 40, 1) any imattacked naphthalene will thus be removed. Pour the warm contents of the flask into a beaker containing a large volume of water which is vigorously stirred. Filter ofiF the granulated a-nitro-naphthalene at the pump, press it well, and recrystallise it from dilute alcohol. The yield of a-nitronaphthalene, m.p. 61°, is 60 g. 

P-Nitronaphthalene is not formed by direct nitration. For the preparation of p-naphthylamine, the Bucherer reaction may be applied to p-naphthol, i.e., by heating with ammoniacal ammonium sulphite solution at 150° (under pressure). The reaction involves the addition of the bisulphite to the keto form of p-naphthol ... 

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... 

Under spectroscopic conditions, a 100% conversion is easily reached and the reaction is reported to be remarkably clean. High 5delds are obtained in preparative runs. In the same way both nitro groups are exchanged for chlorine in 1,5-dinitronaphthalene, whereas 1,8-dinitronaphthalene gives rise to a tiichloro-naphthalene. 2-Nitronaphthalene was unreactive. 

Beilstein Kuhlberg investigated nitration of toluene with mixed nitric-sulfuric acid of various concns and isolated for the first time several isomers of mono- and dinitro-toluene. They also prepd in 1870 TNT, but did not prepare Trinitrobenzene. At about the same time, mono-, di-, tri- and tetra-nitronaphthalenes were prepd (Ref 12, p 18). Trinitrobenzenes were prepd in 1882 by P. Hepp... 

Nitrophthalic acid has been prepared by the oxidation of nitronaphthalene,1 and by the nitration of phthalic acid in a variety of ways by many different workers.2 The present method is based on those of Bogert and Boroschek3 and of Lawrance.4... 

The potassium salt of pcrfluoro-1-naphthol is oxidized similarly but to a mixture of quinoidal structures which are difficult to separate.170 In contrast, quinone structures are obtained in preparative yields by the oxidation of perfluoro-2-naphthol with concentrated nitric acid. The isolable l-nitronaphthalen-2(l //)-one 10 is easily transformed to 1,2-naphthoquinone 11 in high yield.120... 

Nitration of aromatic hydrocarbons is usually carried out with the above mixed acid reagent at comparatively low temperatures (e.g. about 50 °C, as used in the preparation of nitrobenzene and 1-nitronaphthalene, Expt 6.17). Unnecessarily high temperatures should be avoided since polynitration is then more likely and oxidative breakdown of the aromatic ring system may occur. 

The ferrous oxalate procedure has been employed successfully to prepare 8,10-dimethyl-3,4-benzophenanthridine from 2-mesityl-l-nitronaphthalene.85 However, an attempted preparation of 4,9-diazachrysene from 2,2 -dimethyl-6,6/-dinitrobiphenyl failed, while treatment with an excess of triethyl phosphite gave 1,10-dimethyl -benzo[c]cinnoline (11%) as the only recognizable product. Failure... 

The easiest preparation of naphthylamines involves the catalytic reduction of the nitronaphthalenes. 

Thus the authors prepared a- nitronaphthalene from naphthalene with the yield of 80% by warming I with naphthalene. In a similar way toluene was nitrated at 80°C to 2,4-dinitrotoluene (yield 65%). By warming chloroform with I at 40-50°C chloropicrine resulted with the yield of ca. 30%. 

Roussin [11] prepared a mixture of mono- and di-nitronaphthalenes which he was able to separate by utilizing the fact that the latter is not soluble in carbon disulphide,... 

The commercial product obtained by the nitration of a- nitronaphthalene is a mixture of the 1,5- and 1,8- isomers, with only a small content of the 1,3-isomer. The melting point of the product ranges from 140- 160°C. It is used for the preparation of explosives or for further nitration, without separating the isomers. The... 

Pure nitronaphthalene is sent, while still molten, for the preparation of a- naph-thylamine by reduction. 

If a- nitronaphthalene is to be used for preparing explosive compositions, it is poured off from the drying kettle into pans for solidification and then broken up into lumps. 

The product is washed as described below (see preparation of dinitronaphthalene from nitronaphthalene). 

Cognate preparation. 1-Nitronaphthalene. Use 40 ml of concentrated nitric acid and 40 ml of concentrated sulphuric acid with 50 g (0.39 mol) of finely powdered naphthalene as detailed for nitrobenzene. The subsequent heating at 60 °C should be for 30-40 minutes or until the smell of naphthalene has disappeared. Pour the reaction mixture into 500 ml of water decant the washings from the product and then boil the solid with 200 ml of water for 20 minutes. Decant the water and subject the oil to steam distillation (Fig. 2.102) to remove unreacted naphthalene. Pour the warm residue into a large volume of water with vigorous stirring. Filter and recrystallise from dilute alcohol to give pure 1-nitronaphthalene (60 g, 89%), m.p. 61 °C. 

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). 

As we would expect, introduction of these groups opens the way to the preparation of a series of u/p/ra-substituted naphthalenes from 1-nitronaphthalene via the amine and diazonium Its, and from 1-bromonaphthalene via the Grignard reagent. 

Problem 30.13 Diazonium salts can be converted into nitro compounds by treatment with sodium nitrite, usually in the presence of a catalyst. Suggest a method for preparing 2-nitronaphthalene. 

This method is essentially that described by Goldhahn. 4-Nitro-l-naphthylamine has also been prepared by the nitration of a-naphthylamine, acetyl-a-naphthylamine, and ethyl-1-naphthyloxamate, by the oxidation of 4-nitroso-l-naphthyl-amine, and by reaction of 4-chloro-l-nitronaphthalene with ammonia. ... 

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