Nitro, acids naphthalenes

Amino-3-hydroxy-7-nitro-l-naphthalene-sulfonic acid [6259-63-8]... 

EBT indicator solution Dissolve 0.2g EBT (3-hydroxy-4-[(l-hydroxy-2-naphthyl)azo]-7-nitro-l-naphthalene-sulphonic acid, sodium salt) in 100 mL methanol. Filter the solution and store between 0 and 5 C. 

Fischer-Hepp rearrangement The nitros-amines of aromatic secondary amines when treated with hydrochloric acid give nuclear substituted nitrosoamines. Among the benzene derivatives, if the para position is free the -NO group displaces the hydrogen atom there in naphthalene derivatives it enters the 1-position ... 

Davies and Warren" found that when 1,4-dimethylnaphthalene was treated with nitric acid in acetic anhydride, and the mixture was quenched after 34 hr, a pale yellow solid with an ultraviolet spectrum similar to that of a-nitro-naphthalene was produced. However, if the mixture was allowed to stand for 5 days, the product was i-methyl-4 nitromethylnaphthalene, in agreement with earlier findings. Davies and Warren suggested that the intermediate was 1,4-dimethyl-5 nitronaphthalene, which underwent acid catalysed rearrangement to the final product. Robinson pointed out that this is improbable, and suggested an alternative structure (iv) for the intermediate, together with a scheme for its formation from an adduct (ill) (analogous to l above) and its subsequent decomposition to the observed product. 

Fluoronaphthalene [321-38-0] is prepared from 1-naphthylamine by the Balz-Schiemaim reaction in 52% yield or by diazotization in anhydrous hydrogen fluoride in 82% yield. Electrophilic substitution occurs at the 4-position, eg, nitration with fuming nitric acid in acetic acid gave 88% yield of l-fluoro-4-nitro-naphthalene [341 -92-4]. 

Naphthalene-1,8-dicarboxylic add, its nitro-substituted derivatives, and naphthalene-1,4,5,8 tetracarboxylic acid, on treatment with sulfur tetrafluoride at 0 C, undergo dehydration to form quantitatively the corresponding anhydrides [218, 221] Unsubstituted and mononitrated monoanhydndes react further at 200-250 °C to give derivatives of 1,1,3,3-tetrafluoro-l// naphtho[I,8 c,d]pyran Dinitronaphthalene-l,8-di-carboxyhc acid anhydndes and naphthalene 1,4,5,8 tetracarboxylic acid dianhydnde give the respective tetra- and octafluoroethers only in the presence of an excess of anhydrous hydrogen fluoride [221] (equabons 113 and 114)... 

This leaction is lesorted to for the reason that naphthalene forms only the n-nitro-compound with niti icacid. The method, similar to that used for prepaiing aniline from nitiobenzene, cannot, therefore, be employed for the production of /3-n.tphtliyl-.amine. u-Naphthol is mainly used foi the manufacture of yellow and orange colours (Martins and naphthol yellow) by the action of nitric acid, and are similai m constitution to picric acid (see Prep. 107). 

Dinitro-1 -Methylnaphthalene, mp 14.2—43°, needles from ale. Prepn from 5-nitro-1-methyl-naphthalene by nitration on a steam bath using nitric (d 1.52g/cc) coned sulfuric acids in glac AcOH Acj O... 

MNN is obtained in 3—5% yield by the nitration of naphthalene and is present at this level in coml MNN. It is best prepd by indirect methods for example, by the removal of an amino group from an appropriately substituted nitro-naphthylamine. The amine is treated with Na nitrite and acid to form the diazonium salt which is replaced with a H atom by redn with EtOH (Ref 7). It may also be prepd by treatment of 6-nitro-l, 2,3,4-tetrahydronaphthalene with Br to form a dibromo compn (probably the 1,4-isomer), followed by removal of two moles of H bromide by distn in the presence of base (Ref 10). 2-Naphthalenediazonium fluoroborate... 

Nitro-1 -Naphthol (8-Nitro-l-oxy-naphthalene). (O2N)C10H6.OH,mw 189.18, N 7.41%, OB to C02 —173.38%, mp 212° (decompn). Prepn from 1-naphthy 1-m-nitrobenzene sulfonate by nitration with nitric acid in AcOH, then hydrolysis with piperidine... 

Nitro-3,4,6-Tribromo-2-Naphthol (1-Nitio-3,4,6-tribromo-2-oxy-naphthalene). 02N.CloH3Br3.OH, mw 425.87, N 3.29%, OB toC02 -71.38%, turns black at 135°, mp 136° (decompn). Prepn from l,3,4,6 tetrabromo-l-nitro-2-naphthol by reaction with nitric acid, then alkali Ref Beil 6,655... 

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... 

Trinitro-1-Naphthol (2,4,8-Trinitro-l-oxy-naphthalene). Yellow prisms, mp 175°. Sol in cold w. Prepn from 8-nitro-naphthoquinone-(l,4)-oxime by heating with dU nitric acid Ref Beil6, 620 (309)... 

Toxicity. Picric Acid is more toxic than the nitro derivatives of toluene, xylene or naphthalene. It is, however, much less toxic than nitro derivatives of benzene... 

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. 

H acid (4.2) is possibly the most important single naphthalene-based intermediate. The preparation of this intermediate starts with a high-temperature sulphonation of naphthalene using 65% oleum (anhydrous sulphuric acid in which 65% by mass of sulphur trioxide has been dissolved) to give mainly naphthalene-1,3,6-trisulphonic acid, the nitration product from which is purified by selective isolation. Reduction of the nitro group followed by hydrolysis of the 1-sulphonic acid substituent by heating with sodium hydroxide solution at 180 °C completes the process (Scheme 4.27). 

The introduction of halogen and of the nitro-group leads exclusively to the a-derivative. This is also the case with the sulphonic group. When naphthalene is sulphonated at a low temperature, such as that mentioned above, the a-sulphonic acid is produced it can thus be prepared also on a technical scale. The jS-sulphonic acid, on the other hand, is only formed at higher temperatures when the a-acid is, to a large extent, decomposed hydrolytically into naphthalene and sulphuric acid. The equilibrium between sulphonation and hydrolysis at the temperature (170°-180°) here used lies rather to the left in the case of the a-acid, and far to the right in that of the j8-acid. 

Chemical/Physical. Under atmospheric conditions, the gas-phase reaction of o-xylene with OH radicals and nitrogen oxides resulted in the formation of o-tolualdehyde, o-methylbenzyl nitrate, nitro-o-xylenes, 2,3-and 3,4-dimethylphenol (Atkinson, 1990). Kanno et al. (1982) studied the aqueous reaction of o-xylene and other aromatic hydrocarbons (benzene, toluene, w and p-xylene, and naphthalene) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride. The amount of cyanogen chloride formed increased at lower pHs (Kanno et al., 1982). In the gas phase, o-xylene reacted with nitrate radicals in purified air forming the following products 5-nitro-2-methyltoluene and 6-nitro-2-methyltoluene, o-methylbenzaldehyde, and an aryl nitrate (Chiodini et ah, 1993). 

The successive nitration of naphthalene allows the introduction of four nitro groups. Nitration of naphthalene with concentrated nitric acid mainly yields 1-nitronaphthalene and a small amount of 2-nitronaphthalene. Nitration of pure 1-nitronaphthalene with mixed acid yields... 

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