2-Naphthol, oxidation

Oxidation base 13A. See 2-Chloro-p-phenylenediamine sulfate Oxidation base 16. See o-Phenylenediamine Oxidation base 19. See p-Aminoacetanilide Oxidation base 25. See 4-Amino-2-nitrophenol Oxidation base 33. See 1-Naphthol Oxidative base 12. See 4-Methoxy-m-phenylenediamine... 

A catalytic version of the copper(II)-mediated stoichiometric chiral amine naphthol oxidative couplings has been developed as an extension of the successful achiral version. Smrcina and co-workers first carried out such a reaction in order to obtain information on the mechanism of their stoichiometric amine reactions. They obtained the biphenyl product (S)-207 in 41 % yield with a modest enantiomeric excess (32 % ee) (Scheme 56) [88]. 

A 1933 patent claimed the preparation of naphth[l,8-Z)c]oxete (23) along two routes a-naphthol oxidation by iron(lll) chloride, and 1,8-dihydroxynaphthalene dehydration (33BRP394,511) at 300 °C under a carbon dioxide atmosphere. 

A heterosupramolecule, defined by the authors as an artificial microdevice that carries out advanced functions by cooperating with inorganic solids and organic molecules has been constructed from Ti02 and a cationic surfactant. The surfactant, trimethylstearylammonium chloride, forms a bilayer on the surface of the semiconductor, and the substrate, in this case 2-naphthol, is incorporated into hydrophobic nanospaces in the adsorbed bilayer. A very high level of activity for 2-naphthol oxidation to phthalic acid is obtained. The activity is attributed to the concentration of the substrate near the Ti02 surface and an increase in the effective surface area due to the improved dispersibility of the particles. 

Naphthalenol a-Naphthol Oxidation base 33 Classification Polycyclic phenol Empirical CioHjO Formula C10H7OH... 

H,3H,5H-Oxazolo [3,4-c] oxazole-7a(7H)-methanol Oxazolo [3,4-c] oxazol-7a-yl-methanol. See Hydroxymethyl dioxoazabicyclooctane 2-Oxepanone. See e-Caprolactone monomer Oxidation base 33. Seel-Naphthol Oxide of chromium. See Chromium oxide (ic)... 

Naphthol Oxidations. a-Naphthols can be oxidized to 1,2-or 1,4-naphthoquinones by Fremy s salt. Again, the nature of the para substituent is critical. 1,4-Naphthoquinones predominate if the para position is unsubstituted. 1,2-Naphthoquinones are formed if an alkyl or aryl group occupies the para position, if there is a hydroxy group in the 2-position, or if the para position is hindered. Approximately equal amounts of 1,2- and 1,4-naphthoquinones are obtained if a hydroxy group occupies the 5-position. It has been reported that 1,4-naphthoquinones are produced from oxidation of 2- or 9-SMe substituted phenols. fi-Naphthols are generally oxidized to 1,2-naphthoquinones (eq 1). ... 

Fig. 16. The yield of phenol and naphthol oxidation in the presence of Cu++, O2, and morpholine (MH). Both are oxidized to substituted o-quinones.

Although 2-naphthol is employed chiefly for the manufacture of dyes, considerable quantities are used in the manufacture of anti-oxidants. 

Naphthol Antipyrine, camphor, phenol, iron(III) salts, menthol, oxidizing materials, permanganates, urethane... 

Oxidation H ir Colorant. Color-forming reactions are accompHshed by primary intermediates, secondary intermediates, and oxidants. Primary intermediates include the so-called para dyes, -phenylenediamine, -toluenediamine, -aminodiphenylamine, and p- am in oph en o1, which form a quinone monoimine or diimine upon oxidation. The secondary intermediates, also known as couplers or modifiers, couple with the quinone imines to produce dyes. Secondary intermediates include y -diamines, y -aminophenols, polyhydroxyphenols, and naphthols. Some of the more important oxidation dye colors are given in Figure 1. An extensive listing is available (24,28). 

Oxidation inhibitors function by intermpting the hydroperoxide chain reaction. At temperatures up to ca 120°C, di-Z fZ-butyl- -cresol, 2-naphthol,... 

Oxidation. Naphthalene may be oxidized direcdy to 1-naphthalenol (1-naphthol [90-15-3]) and 1,4-naphthoquinone, but yields are not good. Further oxidation beyond 1,4-naphthoquinone [130-15-4] results in the formation of ortho- h. h5 ic acid [88-99-3], which can be dehydrated to form phthaUc anhydride [85-44-9]. The vapor-phase reaction of naphthalene over a catalyst based on vanadium pentoxide is the commercial route used throughout the world. In the United States, the one phthaUc anhydride plant currently operating on naphthalene feedstock utilizes a fixed catalyst bed. The fiuid-bed process plants have all been shut down, and the preferred route used in the world is the fixed-bed process. 

The most important process to produce 1-naphthalenol was developed by Union Carbide and subsequently sold to Rhc ne-Poulenc. It is the oxidation of tetralin, l,2,3,4-tetrahydronaphthalene/719-64-2] in the presence of a transition-metal catalyst, presumably to l-tetralol—1-tetralone by way of the 1-hydroperoxide, and dehydrogenation of the intermediate ie, l-tetralol to 1-tetralone and aromatization of 1-tetralone to 1-naphthalenol, using a noble-metal catalyst (58). 1-Naphthol production in the Western world is around 15 x 10 t/yr, with the United States as the largest producer (52). 

A process variation of the extraction of 2-isopropylnaphthalene hydroperoxide from the cmde oxidation product with an alkylene glycol has been patented (71). The 2-naphthalenol plant of American Cyanamid, which was using the hydroperoxidation process and had a 14 x 10 t /yr capacity (72), ceased production in 1982, leaving the United States without a domestic producer of 2-naphthol. The 2-naphthol capacity in the Western world is approximately 50 x 10 t/yr, with ACNA, Italy and Hoechst AG, Germany operating the largest plants. China produces about 7 x 10 t/yr. Other important producing countries are Poland, Romania, the former Czechoslovakia, and India (35,52). 

Sulfation by sulfamic acid has been used ia the preparation of detergents from dodecyl, oleyl, and other higher alcohols. It is also used ia sulfating phenols and phenol—ethylene oxide condensation products. Secondary alcohols react ia the presence of an amide catalyst, eg, acetamide or urea (24). Pyridine has also been used. Tertiary alcohols do not react. Reactions with phenols yield phenyl ammonium sulfates. These reactions iaclude those of naphthols, cresol, anisole, anethole, pyrocatechol, and hydroquinone. Ammonium aryl sulfates are formed as iatermediates and sulfonates are formed by subsequent rearrangement (25,26). 

An electrorefining plant may operate with either an acid or an alkaline bath. The acid bath contains stannous sulfate, cresolsulfonic or phenolsulfonic acids (to retard the oxidation of the stannous tin in the solution), and free sulfuric acid with P-naphthol and glue as addition agents to prevent tree-like deposits on the cathode which may short-circuit the cells. The concentration of these addition agents must be carefliUy controlled. The acid electrolyte operates at room temperature with a current density of ca 86—108 A/m, cell voltage of 0.3 V, and an efficiency of 85%. Anodes (95 wt % tin) have a life of 21 d, whereas the cathode sheets have a life of 7 d. Anode slimes may be a problem if the lead content of the anodes is high the anodes are removed at frequent intervals and scmbbed with revolving bmshes to remove the slime (7). 

In a biotechnology-based approach, Japanese workers have reported on the microbial conversion of 2-methylnaphthalene to both 2-methyl-1-naphthol and menadione by Jiodococcus (64). The intermediate 2-methyl-1-naphthol can readily be converted to menadione by a variety of oxidizing agents such as heteropoly acids (65) and copper chloride (66). A review of reagents for oxidizing 2-methylnaphthalene and naphthol is available (67). 

Certain dyes when appHed by the afterchrome method are oxidized prior to metal complex formation. Examples iaclude. Chromotrope EB [3567-69-9] (52) (Cl Acid Red 14 Cl 14720) (naphthionic acid — l-naphthol-4-sulfonic acid) ia which a hydroxyl group is iatroduced by oxidation at the... 

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