Nitro-substituted naphthalenes reaction

The reactions of nitrobenzene and 1- and 2-nitro-substituted naphthalenes with ethyl isocyanoacetate in the presence of DBU were found to proceed very slowly [81, 82], and yields of the target isoindoles proved to be extremely low, with conversion of the starting nitro compounds not exceeding 10% (Scheme 44). 

Grignard reagent.80 Competition by nucleophilic aromatic substitution was not observed unless the only active position(s) was (were) substituted with a leaving group, as in the reaction of l-methoxy-2-nitro-naphthalene which gave 1 -alkyl-2-nitronaphthalenes in 73-95% yields.81 The use of Me3SiCH2MgCl (Peterson reagent) provides an entry to nitro-substituted benzyl anion intermediates, as shown in the example of Scheme 9.82... 

An analogous series of dicationic species have been proposed in the reactions of nitro-substituted arenes in superacid. For example, 2-nitro-naphthalene (212) reacts in superacid to give the arylated product (214) in good yield (eq 62).74... 

The nitro substitution products of naphthalene are easily prepared by the action of nitric acid on the hydrocarbon. By such direct nitration the product obtained is alpha-nitro naphthalene. This is proven by the following series of reactions. Nitro-naphfhalene by reduction yields amino naphthalene, naphthylamine, which by the diazo reaction yields hydroxy naphthalene, naphthol. Now the naphthol so obtained is identical with the one resulting from the phenyl vinyl acetic acid synthesis (p. 768) and this must be the alpha compound. 

The (x-substituted naphthalenes, like substituted benzenes, are ihpst commonly prepared by a sequence of reactions that ultimately goes back to a nitro compound (Sec. 30.8). Preparation of / -substituted naphthalenes, on the other hand, cannot start with the nitro compound, since nitration does not take place in the j3-position. The route to /3-naphthylamine, and through it to the versatile dia-zonium salts, lies through /9-naphthol. /9-Naphthol is made from the /3-sulfonic acid it is converted into /8-naphthylamine when heated under pressure with ammonia and ammonium sulfite (the Bucherer reaction, not useful in the benzene series except in rare cases). 

The acylation of 2-substituted naphthalenes usually occurs at l-(a-) position [2]. But there are some exceptions where it can give rise to different kind of isomers by changing the reaction conditions [9]. 2-Methoxy naphthalene (2-MON) has been shown to be acetylated mostly either in l-(a)-position to yield l-acetyl-2-methoxynaphthalene or at 6-(P)-position to yield 2-acetyl-6-methoxynaphthalene depending on the catalyst and solvent systems used [10]. The a-isomer is rep)orted in most of the cases. But in the case of AICI3 catedysed acylation of 2-MON in presence of certain solvents, especially nitro compounds, a solvated nitro complex is formed by which acylation at the P-position is preferred [3]. 

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]. 

To derive the maximum amount of information about intranuclear and intemuclear activation for nucleophilic substitution of bicyclo-aromatics, the kinetic studies on quinolines and isoquinolines are related herein to those on halo-1- and -2-nitro-naphthalenes, and data on polyazanaphthalenes are compared with those on poly-nitronaphthalenes. The reactivity rules thereby deduced are based on such limited data, however, that they should be regarded as tentative and subject to confirmation or modification on the basis of further experimental study. In many cases, only a single reaction has been investigated. From the data in Tables IX to XVI, one can derive certain conclusions about the effects of the nucleophile, leaving group, other substituents, solvent, and comparison temperature, all of which are summarized at the end of this section. 

Tetradehydrodianthracene undergoes 4 + 2-cycloaddition with electron-deficient dienes such as 1,2,4,5-tetrazines.263 The Diels-Alder reactions of [3.3 ortho-anthracenophanes witli A-(p-nitro, chloro, or methoxy-substituted phenyl)malehnides yield approximately equal quantities of inside and outside adducts.264 The photooxidation of bulky water-soluble 1,4-disubstituted naphthalenes with singlet oxygen yields both the expected 1,4- and the unexpected 5,8-endoperoxides.265... 

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