Methoxy-2-naphthol

The preparation of 6-methoxy-2-naphthol is of particular interest as the starting point in many synthetic sequences. It is readily converted to 6-methoxy-2-tetralone through a Birch reduction... 

Methoxy-2-Naphthol. A mixture of 10 g of 6-bromo-2-methoxynaphalene, 0.5 g of copper bronze, 8.5 g of NaOH, and 175 cc of water are shaken in a suitable high pressure vessel at 200° for 75 minute. Cool, dilute with a little water, filter copper off, and acidify with coned HCl acid. Collect the resulting product, wash with water and dry in air. Recrystallize the resulting crude product with dilute ethanol to get a little over 5 g. 

Methyl-[ 5,7-dinitro-8-hydroxy-naphthyl-(l)] -ether, 2,4-Dinitro-8-methoxy-naphthol-(l) ). (02N)2CioH4(OH).O.CH3, mw 264.21, N 10.61%, OB to C02 -121.12%, gold plates from ale, mp 179—80° (decompn). Sol in dil alkali ale. Prepn from 2,4-dinitro-1,8-dime thoxy-naphthalene by reaction with 2N NaOH Ref Beil 6, 5284 ... 

Acetic acid-(2,4-dinitro-5-methoxy-naphthyl-(l)-ester), [2,4-Dinitro-5-methoxy-naphthyl-( 1)] acetate). (02N)2CioH4(C2H302).O.CH3, mw 306.25, N 9.15%, OB to CO2 -125.39%, gold cryst, mp 154 (decompn). Prepn from 2,4-dinitro-5-methoxy-naphthol by refluxing with AC2O coned sulfuric acid Ref BeU 6, 5274 ... 

Mikami et al. have reported that the chiral titanium reagent 12 derived from bi-naphthol and TiCl2(0-i-Pr)2 catalyzes the Diels-Adder reaction of a-bromoacrolein or methacrolein with isoprene or 1-methoxy-l,3-butadiene to afford the cycloadducts with high enantioselectivity [18] (Scheme 1.25). 

Nitroso-1-Naphthol (Naphthochinon-(l,4)-monoxime). ON.CioHg.OH, mw 173.18, N 8.09%, OB to C02 —198.64%, pale yellow needles from benz or dil ale, mp 193—94° (decompn at 190° thru mp). Sol in ale, me ale, acet, eth, chlf C disulfide. Prepn from 4-nitroso-1-methoxy-naphthalene by saponification with mineral acid. 1166.4cal/g-mole q 1166.5 cal/g-mole... 

Table 12-2 gives some of Sterba s results for 1-naphthol, resorcinol, 1-methoxy-naphthalene, 3-methoxyphenol and 1,3-dimethoxybenzene. The data in the table show that the 1-naphthoxide ion is 108 times more reactive than the undissociated naphthol, which is 102 times more reactive than 1-methoxynaphthalene. The rate ratios for the monoanion of resorcinol relative to resorcinol, 3-methoxyphenol, and 1,3-dimethoxybenzene are of similar magnitudes. The dissociation of both OH groups of resorcinol gives rise to a rate constant (2.83 X 109 m -1 s-1) which, in our opinion, is probably mixing- or diffusion-controlled (see Sec. 12.9). 

Nearly 25 years after its discovery the mechanism of the benzannulation reaction has been theoretically and experimentally elucidated in detail. The most predominant outcome of this reaction is the formation of the 4-methoxyphe-nol or 4-methoxy-l-naphthol skeleton coordinated to a Cr(CO)3 fragment. Therefore the mechanism leading to this type of product will be discussed first. 

In geteilter Zelle und 2 n Schwefelsaure laBt sich Phenol an Platin-Kathoden zu Cyclo-hexanol hydrieren (niedrige Stromdichte 56% d.Th.)6,7. Analog reagieren Methyl-phe-nole, -aniline und -benzoesauren sowie Methoxy-toluole usw.7. 1-Naphthol wird zu 7-Hydroxy-dekalin und 2-Naphthol zu 6-Hydroxy-tetralin in mittleren Ausbeuten reduziert7. 

These studies have recently been extended to the naphthalene system.(142) In alkaline media 2-methoxy-5-nitro-, l-methoxy-6-nitro-, and 2-methoxy-7-nitro-naphthalenes all undergo photosubstitutions to produce naphthols ... 

Decyl-5-methoxy-l-naphthol [Reduction of a Secondary Benzylic Alcohol to a Methylene Group with Concomitant Loss of a MOM Protecting Group].167... 

Decy 1-5-methoxy-1 -naphthol reduction procedure, benzyl alcohol reduction, 121... 

Dual-Spectrum Also called Workman. A thermographic copying process. A transparent film base, coated with 4-methoxy-l-naphthol and a photo-reducible dye such as erythrosine, receives the image, which is then transferred to a paper sensitized with sodium behenate. Invented in 1961 by W. R. Workman at the Minnesota Mining and Manufacturing Company, MN, and commercialized for office copying, but later superseded by various electrophotographic processes. 

Trimethylbenzenesulfonyl 30 mol % GaLB was used. f No reaction/4-Methoxy-l-naphthol was used instead of 105. 

Comparative three dimensional X-ray diffraction studies have been carried out on a red and a brown representative of the Naphthol AS pigment series, differing only by the presence or absence of one methoxy group in the anilide function of the coupling component (4). 

A few Naphthol Yellow pigments which are coupling components of the acetoacetic arylide series are also considered members of the Naphthol AS series (see footnote to Table 10, p. 191). These are internationally known as Naphtol AS-G , Naphtol AS-IRG , etc. Naphtol AS-IRG, for instance, is acetoacetic-2,5-methoxy-4-chloroanilide (see also Table 10). 

Experimental Procedure 2.2.3. Benzannulation with a Chromium Phenylcar-hene Complex [ 1 -4 4a,8a-Ti -2-(r rr-Butyl)-4-methoxy-1 -naphthol]tricarbonyl-chromium [37, p 140]... 

After bromination of 144 g. (1 mole) of 2-naphthol, the hot solution is poured into water and filtered. The dry precipitate is mixed with a solution of 200 ml. of concentrated sulfuric acid in 500 ml. of technical methanol and heated to vigorous reflux for 4 hours. An oily layer separates during the heating period. The hot mixture is poured into 3 1. of ice and water, and the solids are removed by filtration. The moist solid is triturated with 11. of hot 5% sodium hydroxide. After chilling the mixture to solidify the oil, it is filtered and the product is washed and dried. The 6-methoxy-2-bromonaphthalene is purified by distillation, b.p. 114-118° (0.2 mm.). After distillation the product is most conveniently handled by remelting and pouring it into a mold to solidify. The overall yield is 173-208 g. (73-88%), m.p. 101.5-103°. 

Methoxy-l-Nitroso-2-Naphthol. A fine suspension of 8 g of the above naphthol in dilute acetic acid (this can be accomplished by adding 75 g of ice to 38 cc of acetic acid) is treated rapidly with 3.17 g of solid sodium nitrite, with vigorous stirring. The mixture is stirred at -5° for 20 min and an additional. 35 g of sodium nitrite is added. Continue stirring for 20 min and the resulting yellow, brown solid is collected, washed well with water, then with methanol and dried. Yield 8.4 g. 

Photocycloadditions of naphthalene derivatives to alkcnes have been recently reviewed.60 Examples of such reactions are the photocycloaddition of naphthalene to 2,3-dihy-drofuran,61 of 4-methoxy-l-naphthonitrile to acrylonitrile62 and of 2-trimethylsiloxynaph-thalene to methyl acrylate.63 2-Naphthols undergo cycloaddition with ethene in the presence of aluminum trihalides only.64 Other bicyclic aromatic compounds, e.g. A-acylindoles65-67 and /V-methylphenanthrene-9,10-dicarboximide,68 have also been studied in detail. Irradiation of 5/f-dibenzo[u,i7]cyclohepten-5-one (21) and dimethyl 2-methylfumarate (22) in dioxane gives the cyclobutane adduct 23 in 73% yield.69... 

HO.CioH3(N02)3.0H mw 295.16, N 14.24% yel ndls (from aq acet ac), mp-dec 260° was prepd by heating 2,4,6-trinitro-5-acetoxy-l-naphthole or 2,6,8-trinitro-5-methoxy-1-acetoxynaphthalene with 2% NaOH (Refs 1 2). No expl props are reported Refs 1) Beil 6, 5275 2) R.H. Thomson... 

When hypofluorous acid reacts with aromatic substrates 7 the isomeric distribution of phenols formed suggests the nature of the transformation is electrophilic, rather than radical 4-methoxy(2-2H)phenol (8) isolated from (4-2H)anisole shows a marked NIH effect (77% incorporation of deuterium).11 A similar reaction with naphthalene gives a mixture of up to three products in low yield (1-naphthol 2.9%, 2-naphthol 0.75% and 1.4-naphthoquinone 7.4%).9... 

The starting material for the 1,2-disubstituted tetrahydro-naphthalenes was 5,6,7,8-tetrahydro-2-naphthol. This compound was converted in low yield to the known Via by the Reimer-Tiemann reaction. VI6 and Vic both were prepared from 1-bromo-2-methoxy-5,6,7,8-tetrahydronaphthalene. Although VI6 was prepared according to the method of O Farrell et al. [3], we obtained a much higher yield,... 

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