1.4- Dimethyl-2-naphthol

Naphthyl methyl ether (nerolin). Use 36 0 g. of p-naphthol, 10-5 g. of sodium hydroxide in 150 ml. of water, and add 31 -5 g. (23 -5 ml.) of dimethyl sulphate whilst the mixture is cooled in ice. Warm for 1 hour at 70-80°, and allow to cool. Filter oflF the naphthyl methyl ether at the pump, wash with 10 per cent, sodium hydroxide solution, then liberally with water, and drain thoroughly. Recrystallise from benzene or methylated spirit. The yield is 33 g., m.p. 72°. 

Dienes can also be used ia Friedel-Crafts cyclo alkylations. For example, treatment of phenol with 2,5-dimethyl-2,4 hexadiene gives 5,5,8,8-tetramethyl,6,7-dihydro-2-naphthol. 

O- Alkylation is comparable to A/-alkylation, but since the sodium salts are water-soluble it is most convenient to treat the phenol or naphthol in aqueous caustic solution with dimethyl sulfate or diethyl sulfate. These are comparatively expensive reagents, and therefore, alkoxy groups are introduced at a prior stage by a nucleophilic displacement reaction whenever possible. 

Heating ll-methyldibenz[6,/][l,4]oxazepine (3) with dimethyl sulfate in boiling toluene for two hours gives the methylene compound 4, which condenses with l-nitroso-2-naphthol to yield the thermo- and photochromic spiro compound 5.45... 

Dinitro-5-methoxy-naphthol-(l), methyl-[6,8-Dinitro-5-hydroxy-naphthyl-(])] -ether). (O2N)2C10H4(0H).O.CH3, mw 264.21, N 10.61%, OB to C02 —121.12%, orange needles from CCI4, mp 173° (decompn). Sol in CCI4. Prepn from 2,4-dinitro-naphthalenediol-(l,5) by reacting with an excess of dimethyl sulfate in dil NaOH... 

Orange 1 - 4-Phenylazo)-2-naphthol Yellow N,N-Dimethyl-p-phenylazoaniline Blue 1,4-Diamylaminoanthraquinone Mixts of these dyes produce muddy colors of various hues... 

Formation of hydrogen bonds between phenols and naphthols on the one hand, and dimethyl, divinyl, diphenyl sulphoxides and other sulphinyl or sulphonyl derivatives on the other, have also been documented in the literature95-97. 

Alkoxy(carbene)iron(0) and amino(carbene)iron(0) complexes usually react with alkynes to give rj4-pyrone iron complexes and furans, respectively [54]. Nevertheless the chemoselective formation of naphthols was reported for alkoxy(carbene)iron(0) complexes with the electron-poor alkyne dimethyl... 

Bindschedler s Green (6.204) can be made by condensing p-nitroso-N,N-dimethylaniline with N,N- dimethyl aniline. A similar condensation with 2-naphthol gives Meldola s Blue (6.209 Cl Basic Blue 6), the first oxazine dye, discovered in 1879. The symmetrical Cl Basic Blue 3 (6.210) is of more commercial significance. It is synthesised by nitrosation of N,N-diethybrn-anisidine followed by condensation with N,N-diethybm-aminophenol, and is used for dyeing acrylic fibres. This dye is now classified by ETAD as toxic [73]. 

Methylbutyl acetate, see sec-Amyl acetate 3-Methylbutyl acetate, see Isoamyl acetate 3-Methyl-l-butyl acetate, see Isoamyl acetate 3-Methylbutyl ethanoate, see Isoamyl acetate Methylbutyl ethyl ketone, see 5-Methyl-3-heptanone Methyl n-butyl ketone, see 2-Hexanone Methylcarbamate-l-naphthalenol, see Carbaryl Methylcarbamate-l -naphthol, see Carbaryl Methyl carbamic acid, 2,3-dihydro-2,2-dimethyl-7-... 

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... 

Synthesis of racemic naproxene Friedel-Crafts acylation (aluminum chloride - nitrobenzene) of p-naphthol methyl ether affords 2-acetyl-6-methoxy naphthalene, which, when treated with either dimethyl sulfonium or dimethylsulfoxonium methylide, gives 2-(6-methoxynaphthalen-2-yl)propylene oxide. Treatment of the latter with boron trifluoride etherate in tetrahydrofuran gives 2-(6-methoxynaphthalen-2-yl)propionaldehyde, which is oxidized using Jones reagent (4 M chromic acid) to yield the racemic 2-(6-methoxynaphthalen-2-yl)propionic acid. 

REPELLENT. 1. A substance that causes and insect of animal to turn away from it or reject it as food. Repellents may be in the form of gases (olfactory), liquids, or solids (gustatory). Standard repellents for mosquitos, ticks, etc., arc dtronella oil, dimethyl phthalatc, w-butylmcsityl oxide oxalate, DEET, and 2-ethyl hexanediol-1,3. Actidione is the most effective rodent repellent, but is too toxic and too costly to use. Copper naphthenate and lime/sulfnr mixtures protect vegetation against rabbits and deer. Shark repellents are copper acetate or formic acid mixed with ground asbestos. Bird repellents are chiefly based on taste, but this sense varies widely with the type of bird so that generalization is impossible. G -Naphthol, naphthalene, sandalwood oil, quinine, and ammonium compounds have been used, with no uniformity or result. 

This is exemplified in a-naphthol formation (Eq. 22.2) or in the synthesis of / -methoxybenzonitrile from 1,4-dimethoxybenzene (hydroquinone dimethyl ether) [24] ... 

This reagent has proved especially important in the study of the constitution of the sugars, and of cellulose. A series of methyl-celluloses has been obtained, and by the study of their hydrolysis, or decomposition in a vacuum, some light has been thrown on the structure of the cellulose molecule. (J. S. C. I., 41, 362 R.) In the laboratory dimethyl sulphate is much employed in the methylation of phenols and naphthols. Diethyl sulphate is not so suitable for such alkylations as its lower homo-logue. 

It is also possible to examine the effect of oxygen substituents on the stability of arenonium ions. Wirz has studied keto-enol equilibria for phenol,151 naphthol (Wirz J, Personal communication), and anthrol.152,153 The tautomeric constants may be combined with p/y,s for protonation of the keto tautomer and ionization of the phenol to provide pifas f°r protonation of the aromatic ring of phenol and the phenoxide ion. As illustrated in Scheme 18 the unstable keto tautomer of phenol 22 was produced by photolysis of the bicyclooctene dione 21. Except in the case of the anthrone a pA a for protonation of the keto tautomer has not been measured directly. However, values can be estimated from the pfor protonation of the 4,4-dimethylated analog136 with a correction for the substituent effect of the methyl groups. 

Conversion of phenols into their methyl or ethyl ethers by reaction with the corresponding alkyl sulphates in the presence of aqueous sodium hydroxide affords a method which avoids the use of the more expensive alkyl halides (e.g. the synthesis of methyl 2-naphthyl ether and veratraldehyde, Expt 6.111). Also included in Expt 6.111 is a general procedure for the alkylation of phenols under PTC conditions.38,39 The method is suitable for 2,6-dialkylphenols, naphthols and various functionally substituted phenols. The alkylating agents include dimethyl sulphate, diethyl sulphate, methyl iodide, allyl bromide, epichlorohy-drin, butyl bromide and benzyl chloride. 

Oxamyl (melhyl-N.N -dimethyl-N- [ (methyl-carbarn oyl)oxy] -1 -thio oxamidate) Plants including leaves, potato, tomato and wheat Ethyl acetate extraction of sample Addition of excess copper sulfate, back-titration with standard EDTA to 1 -(2-pyridylazo)2-naphthol [61]... 

Alkylisocyanates react with dimethyl acetylenedicarboxylate to form the reactive intermediate 122, which can be trapped by phenols to afford dimethyl 2-amino-4//-chromene-3,4-dicarboxylates in high yield (Scheme 40) <2003T9409>. Likewise, alkylisocyanates react with dibenzoyl acetylene and naphthols to yield the corresponding 2-amino-3,4-dibenzoyl-4//-chromenes <2003T1289>. 

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