Naphthylamine from 0-naphthol

BUCHERER - LE PETIT Naphthol(Naphthylamine)Synthesis Synthesis of naphthylamines from naphthols and naphthots from naphthylamines... 

The kinetic isotope effects shown in Fig. 11 (Forster, 1972) resemble those reported for 2-naphthol by Stryer (1966). Like 2-naphthylamine, 2-naphthol shows an increased quantum yield and protonation of Sj occurs at lower acidities in D20 than in H20. For 2-naphthol, p-KJSj )-values of 3 0 in H20 and 3-4 in D20 are calculated from the measured excited state rate constants in H20 k.j = 5-29 x 107 s 1 and k2 = 5-5 x 101 0 dm3 mole-1 s-1, while in D20 k1 = 1 3 x 107 s-1 and k2 = 3-5 x 1010 dm3 mole-1 s-1. These results confirmed the earlier p/ (S )-values calculated by Wehry and Rogers (1966) using the Forster cycle (Table 9), which show incidentally that the pK-values are closer by about 0 1 unit in the Sj state. 

The most important dyes derived from naphthylamine sulphonic acids and from naphthol sulphonic acids result from coupling them as azo compounds with other rings. This coupling is effected through a diazonium salt made by diazotizing an amine and bringing this di-... 

Bucherer carbazole synthesis. Formation of carbazoles from naphthols or naphthylamines, aryl-hydrazines, and sodium bisulfite. 

The naphthylamines may be prepared by reduction of the corresponding nitro compound, but they are readily accessible from naphthols by the Bucherer reaction The naphthol is heated, preferably under pressure in an autoclave, with ammonia and aqueous sodium hydrogen sulfite solution, when an addition-elimination sequence occurs. The detailed mechanism is not completely elucidated, but the Bucherer reaction is restricted to those phenols that show a tendency to tautomerize to the keto form, such as the naphthols and 1,3-dihydroxybenzene (resorcinol). Using 1-naphthol for illustration, the first step is addition of the hydrosulfite across the 3,4-double bond of either the enol or keto tautomer (Scheme 12.9). Nucleophilic attack by ammonia at the carbonyl group... 

The complex spiro hetero-/-fused naphtho[l,2-6]pyrans e.g. 63 show two absorption bands (444 - 474 and 568 - 582 nm) and have half-lives of 2 - 3 minutes <00JP344761, 00JP344762>. The synthesis of 4-acetoxy-l-phenyl-2-naphthylamine from 4-hydroxy-l-phenylnaphthalene-3-carboxylic acid allows annulation of an isoquinoline unit onto 1-naphthol and subsequent reaction with a propynol yields the fused pyranophenanthridine 64, Xmax 550 nm, t /2= 12 s (polymethacrylate) <02USP6379591>,... 

BUCHERER - LE PETIT Naphtbol(Naphthylamine)Synthesis Synthesis of naphthylammes from naphthols and naphfhols from naphthylatrvnes... 

Reversible formation of P-naphthylamine from p-naphthol and aqueous ammonium sulfite or bisulfite via intermediate formation of tetralonesulfonic and tetraloneiminosulfonic acids ... 

Bucherer Reaction. The reversible conversion of a naphthylamine to a naphthol in the presence of an aqueous sulfite or bisulfite is valuable in the synthesis of naphthalene dye intermediates. It is used in the preparation of naphthols from naphthylamine or is employed for the reverse transformation—naphthyl-amines from naphthols ... 

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... 

Nitro-l-diazo-2-naphthol-4-sulfonic acid prefers the 2-position in spite of the nitro group, and increasing alkalinity favors ortho coupling with diazophenols. 1-Naphthalenesulfamic acid [24344-19-2] (ArNHSO H) and N-nitro-1-naphthylamine [4323-69-7] (ArNHNO ) couple exclusively in the para position. The substitution of resorcinol [108-46-3] and y -phenylenediamine [108-45-2] is compHcated and has been discussed (29,30). The first azo dyes from aniline, eg. Aniline Yellow [60-09-3] (19) (Cl Solvent Yellow 1 Cl 11000) were manufactured in 1861 and Bismark Brown [10114-58-6] (20) (Cl Basic Brown 1 Cl 21000) appeared in 1863. The reaction is as follows ... 

BUCHERER LE PETIT Naphthol (Naphihylamine) Synthesis Synthesis of naphihylamines tram naphthols and naphihols from naphthylamines... 

An important reaction in the chemistry of naphthalenes is the Bucherer reaction,i.e. the conversion of naphthols 1 to naphthylamines 2 as well as the reverse reaction. The reaction is carried out in aqueous medium in the presence of catalytic amounts of a sulfite or bisulfite. Apart from very few exceptions it does not apply to benzene derivatives, which limits the scope of that reaction. 

Dinitro-1 -Naphthol (4,6-Dinitro-1 -oxy-naphthalene). Crysts from methanol (as Na salt), mp 240°. Sol in chlf. Prepn from 1,4,6-trinitro-2-naphthylamine by diazotization in AcOH-sulfuric acid to yield 4j6-dinitro-2-diazo-... 

P-Bromonaphthalene. The preparation from p-naphthylamine, which has carcinogenic properties, is avoided by the use of 2-naphthylamine-1-sulphonic acid ( 2-amino-1-naphthalenesulphonic acid ) the latter is obtained commercially by cautious treatment of p-naphthol with sulphuric acid—the SOjH group first enters the 1-position—followed by the Bucherer reaction. Diazotisation and reaction with cuprous bromide yields 2-bromonaphthalene-l-sulphonic acid heating with sulphuric acid eliminates the sulphonic acid group to give 2-bromonaphthalene. 

The reaction just described is carried out technically on a large scale in iron vessels provided with stirrers, for /9-naphthol, as well as the numerous sulphonic acids which can be obtained from it by the action of sulphuric acid, is widely used for the preparation of azo-dyes. Moreover, by the action of ammonia under pressure, /3-naphthylamine is produced from /S-naphthol ... 

Naphthylamine and also its sulphonic acids are likewise employed technically for the manufacture of azo-dyes. In the same way a-naph-thol is made from naphthalene-a-sulphonic acid by fusion with sodium hydroxide although on a smaller scale than /3-naphthol. a-Naphthyla-mine, on the other hand, is obtained by the reduction of a-nitronaph-thalene (analogy to aniline). The fusion of alkali salts of arylsulphonic acids with alkali also serves technically for the production of pure phenol and of many phenol derivatives. 

Let us now turn to compounds with more than one benzenoid ring. The first species are the isomeric a- and /J-naphthylamincs, 18a and 18b. The archival enthalpies of formation are found to be 157.6 6.9 and 133.8 5.1 kJmol-1. The 24 9 kJmol-1 difference of these two numbers is incompatible with the near-zero difference of the enthalpies of formation for the isomeric naphthols, methyl- and bromonaphthalenes32. Which or either naphthylamine has the correct enthalpy of formation The gas-phase enthalpies of formation of the naphthols differ from their single benzene ring analog, phenol, by 66 kJmol-1 in close agreement with the difference between the methylnaphthalenes and toluene, 63, and between the brominated and parent hydrocarbons, 69 6 and 68 2 kJmol-1 respectively. That is, it is plausibly asserted33 that the difference quantities 17 are nearly constant and equal. 

What about jr-electron donor substituents on nitrosoarenes other than dimethylamino Pedley gives us the enthalpies of formation for three hydroxy derivatives the isomeric 4-nitroso-l-naphthol, 2-nitroso-l-naphthol and l-nitroso-2-naphthol, species 45-47 respectively. Of the three species, only the first cannot have an intramolecular hydrogen bond. By analogy to nitrophenols75 — there being no thermochemical data for the more related and hence relevant nitronaphthols—we expect that species 46 would be less stable than 45. After all, gaseous 2-nitrophenol is ca 20 kJ mol 1 less stable than its 4-isomer. We recall from the discussion of the isomeric naphthylamines that 1- and 2-naphthol are of almost identical stability. This suggests that species 46 and 47 should be of comparable stability. Both expectations are sorely violated by the literature results the enthalpies of formation of species 45, 46 and 47 increase in the order —20.3 4.9, —5.4 6.2 and 36.1 4.7 kJmol-1 respectively. If there is experimental error, where does the error lie ... 

Seventeen priority pollutant compounds can be classified as polynuclear aromatics (PNA). These compounds consist of two or more benzene rings that share a pair of carbon atoms. They are all derived from coal tar, with naphthalene being the largest constituent. Naphthalene derivatives such as alpha-naphthylamine and alpha-naphthol are used in some pesticide processes therefore, naphthalene is by far the most prevalent PNA priority pollutant in the industry. Acenaphthene, anthracene, fluorene, fluoranthene, and phenathrene are found as raw material impurities. Acenaphthene is found in one pesticide process as a raw material. The remaining ten PNAs are not suspected to be present in pesticide processes. 

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