Nitration of naphthalene

Prepared by the direct nitration of naphthalene with a mixture of nitric and sulphuric acids. Its chief use was for the preparation of l-naphthyiamine and its derivatives. 

The nitration of naphthalene and its derivatives has been much studied,... 

Davies and Warren have investigated the nitration of naphthalene, ace-naphthene and eight dimethylnaphthalenes in acetic anhydride at o °C. Rates relative to naphthalene were determined by the competition method, and the nitro-isomers formed were separated by chromatographic and identified by spectrophotometric means. The results, which are summarised in the table, were discussed in terms of various steric effects, and the applicability of the additivity rule was examined. For the latter purpose use was made of the data of Alcorn and Wells (table 10.2) relating to the nitration of monomethyl-naphthalenes at 25 °C. The additivity rule was found to have only limited utility, and it was suggested that the discrepancies might be due in part to the... 

Nitronaphthalene. 1-Nitronaphthalene is manufactured by nitrating naphthalene with nitric and sulfuric acids at ca 40—50°C (37). The product is obtained in very high yield and contains ca 3—10 wt % 2-nitronaphthalene and traces of dinitronaphthalene the product can be purified by distillation or by recrystaUization from alcohol. 1-Nitronaphthalene is important for the manufacture of 1-naphthalenearnine. Photochemical nitration of naphthalene by tetranitromethane in dichioromethane and acetonitrile to give 1-nitronaphthalene has been described (38). 

As in the nitration of naphthalene, sulfonation gives the 1-substituted naphthalene. However, because the reverse reaction (desulfonation) is appreciably fast at higher temperatures, the thermodynamically controlled product, naphthalene-2-sulfonic acid, can also be obtained. Thus it is possible to obtain either of the two possible isomers of naphthalene sulfonic acid. Under kineticaHy controlled conditions naphthalene-l-sulfonic acid [85-47-2] (82) is obtained thermodynamic control gives naphthalene-2-sulfonic acid [120-18-3] (83). 

In Ref 8 are discussed the effects of acid concns on the formn of mono- and polynitro compds by the mixed acid nitration of naphthalene. Other studies on the coml prodn of 1-MNN are in Refs 16, 20,29 30... 

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... 

Below is collected info on mixts of DNN and on compds of unspecified structure. The nitration of naphthalene with mixed acid gives a 2 1 mixt of 1,8- and 1,5-DNN contg a small amt oflhe 1,3- isomer (Ref 54), This is the compn of the coml DNN used in the expls industry... 

Preparation. On a coml scale the nitration of naphthalene is carried out in two steps using a cylindrical jacketed reactor 1.6 x lm with a conical bottom. It is fitted with a discharge pipe 8cm in diameter and a stirrer which can be rotated at 85—90rpm. The jacket can be heated with steam or cooled with cold w. The cover is provided with an opening for the addn of naphthalene and a vent for the removal of gaseous prods... 

Higher Nitrated Naphthalenes, besides the claim by KatalystChemie, FrP 821767 (1937) CA 32, 3964 (1938), that penta- and hexanitro-naphthalenes can be prepd by nitration of naphthalene if certain catalysts are used, no higher nitrated naphthalenes have been reported in the literature... 

For the nitration of naphthalene a ratio of 1- to 2-mononitronaphthalene of about 20 1 is found in industrial processes. This ratio is dramatically increased to more than 30 by using micro reactors [166]. 

The nitration of naphthalene was used as a test reaction [37]. As a consequence of having two aromatic rings, a particularly large variety of nitration products are in principle possible. This refers to multiplicity of nitration and to positional selectivity for each nitration step. 

P 24] The nitration of naphthalene was carried out with dissolved or in situ generated N2O5 gas [37]. The temperatare was set to -10 to 50 °C and residence times to 15—45 s. The reaction mixtare processed in the micro reactor was quenched with water, extracted and analyzed by HPLC or GC with mass-selective detection. 

Figure 4.48 Product spectra and isomer ratios for the nitration of naphthalene with HNOj in micro reactors from different suppliers [98],...

Nitration of naphthalene-1-sulphonic acid produces two isomeric nitronaphthalenes that have very similar solubilities. It is convenient to reduce the mixture without separation, giving a mixture of l-naphthylamine-8-sulphonic acid (4-44 Peri acid) and 1-naphthylamine-5-sulphonic acid (4.45 Laurent s acid), as in Scheme 4-29. These two... 

For instance, nitration of naphthalene, azulene, biphenylene, and triphenylene proceeds preferentially in positions with the greatest constant of hyperfine splitting at the hydrogen atom in ESR spectra of corresponding cation-radicals. The constant is known to be proportional to the spin density on the carbon atom bearing the mentioned hydrogen. It is important, however, that the same orientation is also observed at classical mechanism of nitration in cases of naphthalene, azulene, and biphenylene, but not triphenylene (see Todres 1985). 

Examples of mnltiplicity of nitration mechanisms that depend on IPs of substrates are the nitration of naphthalene (NaphFI + N02 system) and perylene (PerH -I- N02 system) (Scheme 4.40). 

According to Scheme 4.40, NaphH cation-radical cannot be formed as a result of interaction of NaphFI with NOj. In this sense, Ridd s work is relevant (see Johnston et al. 1989, 1991). The work shows that, to some extent, the nitration of naphthalene can indeed proceed through an outer-sphere... 

A kinetic study of nitrous acid-catalyzed nitration of naphthalene with an excess of nitric acid in aqueous mixture of sulfuric and acetic acids (Leis et al. 1988) shows a transition from first-order to second-order kinetics with respect to naphthalene. (At this acidity, the rate of reaction through the nitronium ion is too slow to be significant the amount of nitrous acid is sufficient to make one-electron oxidation of naphthalene as the main reaction path.) The reaction that initially had the first-order in respect to naphthalene becomes the second-order reaction. The electron transfer from naphthalene to NO+ has an equilibrium (reversible) character. In excess of the substrate, the equilibrium shifts to the right. A cause of the shift is the stabilization of cation-radical by uncharged naphthalene. The stabilized cation-radical dimer (NaphH)2 is just involved in nitration ... 

Nitration of naphthalene (NaphH) by means of dinitrogen tetroxide is described as follows NaphH -f 2N2O4 NaphNOj + HNO3 -l- N2O3... 

In reality, nitration of naphthalene with dinitrogen tetroxide in an aprotic medium is a complex process. The leading role belongs to nitrosyl cation. This species is a strong oxidant acting according to the outer-sphere mechanism (compare with Section 1.7.10) ... 

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... 

We observe that nitration of naphthalene using nitric acid-sulfuric acid gives predominantly 1-nitronaphthalene (sometimes a-nitronaphthalene), and... 

Felhoen Powder — patented in England in 1879 consisted of 90p of Black Powder with 10p of a product obtained on nitration of naphthalene (lp) with 4parts of nitric acid (d 1,4). The nitrated product consisted of mononitronaphthalene with a small amount of the dinitro-compd Ref Daniel (1902), 298... 

The nitro group does not undergo migration of the naphthalene ring during the usual nitration procedures. Therefore, mono- and polynitration of naphthalene is similar to low temperature sulfonation, The nitronaphthalenes and some of their physical properties arc listed in fable 2. Many of these compounds are not accessible by direct nitration of naphthalene but are made by indirect methods, e.g nitrite displacement of diazonium halide groups in the presence of a copper catalysts, decarboxylation of nitronaphtbalcnccar-boxylic acids, or deamination of nitronaphthalene amines. They are nsed in the manufacture of chemicals, dye intermediates, and colorants for plastics. 

The commercial product of the dinitration melts at about 140°, and consists principally of the a- and /3-compounds. The nitration of naphthalene at very low temperatures,44 —50° to —60°,. gives good yields of the y- compound, and some of this material is undoubtedly present in the ordinary product. 

Nitration of naphthalene by use of cerium(IV) ammonium nitrate suspended on silica gel, or in homogeneous solution, in the presence of alcohols, sodium or tetrabutylammonium nitrite and acid gives mainly l-alkoxy-4-nitronaphthalenes together with some of the 2-nitro isomers.34 The results are consistent with initial attack by N02- alone or complexed with cerium(IV) ion at the 1- and 2-positions in a ratio of 5 1. 

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