Naphthols derivatives

Azoic Dyes. These are used to produce cost-effective heavy yellow, orange, red, maroon, navy blue, brown, and black shades and are ptinted alongside other dye classes to extend the coloristic possibiUties for the designer. Two approaches are adopted. The common method ia the United States is to use both a naphthol derivative and a stabilized color base, usually in the form of a diazo imino compound in the same print paste. This mixture is soluble in dilute caustic soda and no coupling takes place at this stage. The dried prints are passed through steam at 100—105°C that contains acetic and/or formic acid vapor. As neutralization takes place on the print, the coupling occurs rapidly and the insoluble azoic dye is formed. 

The 2a,7b-dihydrocyclobuta[7>]benzofuran structure, obtained by addition of activated acetylenes to benzofurans (see Houben-Weyl, Vol.E6b, p 148), isomerizes thermally to a 1-benz-oxepin182 184 185 which reacts further to 1-naphthol derivatives at higher temperature182,185 (see Section 1.2 ). Under photochemical conditions, the 1-benzoxepins undergo ring contraction to the starting material.182 184... 

Benzoxepins are capable of rearranging to naphthalene derivatives 4 and 5 under thermal conditions.182,185,246,247 When 3,5-diacetoxy-4-phenyl-l-benzoxepinis heated to 150°C a mixture of 1- and 2-naphthol derivatives 4a and 5a is obtained due to the intramolecular acetylation of the reactive intermediate.246... 

The reaction between epoxides and ammonia is a general and useful method for the preparation of P-hydroxyamines. " Ammonia gives largely the primary amine, but also some secondary and tertiary amines. The useful solvents, the ethanolamines, are prepared by this reaction. For another way of accomplishing this conversion, see 10-54. The reaction can be catalyzed with Yb(OTf)3 and in the presence of a-BINOL is l,l -bi-2-naphthol derivative gives amino alcohols with high asymmetric induction. A variation used Yb(OTf)3 at lOkbar or at ambient pressure. Lithium triflate can also be used. Primary and secondary amines give, respectively, secondary and tertiary amines, for example. 

The reaction course has not been elucidated (cf. also sodium hydroxide reagent). Hydrolyzation reactions and aromatizations are probably primarily responsible for the formation of colored and fluorescent derivatives. Substituted nitrophenols - e.g. the thiophosphate insecticides — can probably be hydrolyzed to yellow-colored nitro-phenolate anions by sodium hydroxide or possibly react to yield yellow Meisenheimer complexes. Naphthol derivatives with a tendency to form radicals, e.g. 2-naphthyl benzoate, react with hydrolysis to yield violet-colored mesomerically stabilized 1,2-naph-thalenediol radicals. 

Lukeman, M. Veale, D. Wan, R Munasinghe, V. R. N. Corrie, J. E. T. Photogeneration of 1,5-naphthoquinone methides via excited-state (formal) intramolecular proton transfer (ESIPT) and photodehydration of 1-naphthol derivatives in aqueous solution. Can. J. Chem. 2004, 82, 240-253. 

Naphthol AS pigments, 9 425 Naphthol couplers, 19 252-253 in chromogenic chemistry, 19 251 a-Naphthol derivatives, 21 145 P-Naphthol derivatives, 21 145 Naphthol dyes, 9 182, 407 08 Naphthol reds/maroons, 19 437-438 Naphtholsulfonic acids, 9 356 N aphthopyrans... 

For orange colours, simple 2-naphthol derivatives are the most commonly used coupling components as, for instance, in 2,4-dinitroaniline—>2-naphthol (4.118 Cl Pigment Orange 5). As in the yellow series, superior disazo pigments can be prepared using 3,3 -dichlorobenzidine as tetrazo component with derivatives of 1 -phenyl-3-methylpyrazol-5-one as couplers. 

Fig. B4.3.1. Schematic illustration of the average residence sites of the probes NOH (1), NSOH (2), NDSOH (3) in AOT reverse micelles. Length of the surfactant 11 A. Diameter of the water pool 18A at w = 3, 36A at w = 9. Largest dimension of the naphthol derivatives 9 A (adapted from Bardez et al.a ).

Collier et al. (10) demonstrated that HPLC was an effective technique for the separation of aromatic hydrocarbon metabolites in exposed marine organisms. Radioactive bioconversion products were studied in liver and gall bladder of coho salmon dosed with H-naphthalene. Quantitative identifications of glucuronide, sulphate, dihydrodiol, glycoside, and 1-naphthol derivatives were obtained. Three additional polar compounds of unknown structure were found. A typical HPLC profile is shown in Figure 2. 

The potential utility of the Mannich-type phenolic bases makes the aminoalkyla-tion reaction of naphthol derivatives a subject of current chemical interest. But, because of the relatively low reactivity of 1-naphthol, the reaction gave only a moderate yield and displayed moderate diastereoselectivity [5]. 

Uses Intermediate for phthalic anhydride, naphthol, 1,4-naphthoquinone, 1,4-dihydro-naphthalene, 1,2,3,4-tetrahydronaphthalene (tetralin), decahydronaphthalene (decalin), 1-nitro-naphthalene, halogenated naphthalenes, naphthol derivatives, dyes, explosives mothballs manufacturing preparation of pesticides, fungicides, detergents and wetting agents, synthetic resins, celluloids, and lubricants synthetic tanning preservative emulsion breakers scintillation counters smokeless powders. 

The first systematic investigations of the catalytic Friedel-Crafts-type reaction with alcohols and olefines were performed by Yamamoto and colleagues. After reporting the development of a Pd-catalyzed method for the allylation of different naphthol derivatives [24], the authors used Mo(CO)g for the Friedel-Crafts-type alkylation of electron-rich arenes with allyl acetates [25], The same molybdenum catalyst was additionally used for a Friedel-Crafts-type alkylation of arenes using 1-phenylethanol and styrene as alkylating reagents [26], However, Mo(CO)g is toxic and must be handled under strictly inert conditions. Thus, more stable Lewis acids were necessary. 

Cycloaddition between Propargylic Alcohols and Phenol and Naphthol Derivatives... 

Scheme 7.28 Cycloaddition of propargylic alcohols with phenol and naphthol derivatives.

CATALYTIC OXIDATIVE CROSS-COUPLING REACTION OF 2-NAPHTHOL DERIVATIVES... 

Table 8.2 shows the results of the cross-coupling reaction between two differently substituted 2-naphthol derivatives using the CuCl-(5)Phbox catalyst. In conclusion, the first catalytic asymmetric oxidative coupling with a high cross-coupling selectivity was accomplished under mild conditions. 

Propranolol is chemically a naphthol derivative (dl-(isopropylamino)-3-(l-naphthyloxy)-2-propanol). It is a racemic mixture, and the laevo form is the active P-adrenergic blocking agent [10]. After oral administration, it is completely absorbed [11]. However, the systemic availability is relatively low with considerable variation in plasma levels [12,13]. The hepatic extraction of propranolol is about 80- 90%, and thus the main route of drug elimination is via hepatic metabolism [14]. One of the maj or metabolites of propranolol is 4-hydroxypropranolol, and the half-life has been reported to be 3 l-l/2h [15-18]. Since the drug is rapidly metabolized after oral administration, it necessitates a multiple dosage after oral strict patient compliance. 

Salicylic acid derivatives serve a similar purpose to 2-hydroxyacetophenones in a number of chromone syntheses, acting as a precursor of the 1,3-diketone fragment. For instance, a Claisen reaction between methyl 2-methoxybenzoate and acetone takes place in the presence of sodium to give the diketone. Demethylation occurs on reaction with hydriodic acid with concomitant ring closure to the chromone (00CB1998). The corresponding naphthol derivatives are a source of benzochromones (52JOC1419). 

The synthesis has been extended to benzochromanones (611) through the cyclization of naphthyloxypropanoic acids. If the 1-position of the naphthol derivative is occupied, cyclization gives the linear benzochromanone (612) (66BSF3249). 

The reaction of octafluoronaphthalene with 90% hydrogen peroxide at 100 °C gives a complex mixture of products that includes naphthoquinone, naphthol derivatives, and benzene denvatives as products of nng degradation [47]... 

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