2-naphthol, 1-Methyl

Methyl-2-naphthylamlne (2) A mixture ol 1 methyl 2 naphthol 1 (7 8 g, 50 mmol), NaHSOs (10 g 0 1 mol) 28% NH4OH (40 mL) and water (10 mL) was healed to 200 205°C lor 48 (1 The cooled solution was made alkaline with NaOH solution and extracted with EI2O The dned ether solution was treated with HCI gas to allord 2 hydrochlonde which was littered treated with alkali and extracted with El20 Evaporation ol the solvent gave 7 2 g ol 2 (S3%), mp 46 SQ C Recrysiallized from petroleum ether (bp 60 70°C) mp 49 50°C... 

H BrjNO Dibnmunethyl-naphthocliiiiibol aus 4.6-I>ibrom-l-methyl-naphthol-(2)... 

A contact insecticide with the trade name Sevin . White solid, m.p. 142 C. It is prepared by reaction of I-naphthol with methyl isocyanate or with phosgene and a base. 

Required Benzeneazo-naphthol from above experiment methylated spirit, 100 ml. stannous chloride, 22 g. hydrochloric acid, 60 ml. 

Naphthol, Ethanolic, 1%. Dissolve 1 g. of i-naphthol in methylated spirit and make up to 100 ml. with spirit. 

It is interesting to note that azo dyestuffs may be conveniently reduced either by a solution of stannous chloride in hydrochloric acid or by sodium hyposulphite. Thus phenyl-azo-p-naphthol 3delds both aniline and a-amino-p-naphthol (see formula above), and methyl orange gives p-aminodimethylaniline and sulphanilic acid ... 

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°. 

Diazo coupling involves the N exocyclic atom of the diazonium salt, which acts as an electrophilic center. The diazonium salts of thiazoles couple with a-naphthol (605). 2-nitroresorcinol (606), pyrocatechol (607-609), 2.6-dihydroxy 4-methyl-5-cyanopyridine (610). and other heteroaromatic compounds (404. 611) (Scheme 188). The rates of coupling between 2-diazothicizolium salts and 2-naphthol-3.6-disulfonic acid were measured spectrophotometrically and found to be slower than that of 2-diazopyridinium salts but faster than that of benzene diazonium salts (561 i. The bis-diazonium salt of bis(2-amino-4-methylthiazole) couples with /3-naphthol to give 333 (Scheme 189) (612). The products obtained from the diazo coupling are usuallv highly colored (234. 338. 339. 613-616). 

Naphthol is mainly used in the manufacture of the insecticide carbaryl (59), l-naphthyl A/-methyicarbamate/ iJ-2j5 - (Sevin) (22), which is produced by the reaction of 1-naphthol with methyl isocyanate. Methyl isocyanate is usually prepared by treating methylamine with phosgene. Methyl isocyanate is a very toxic Hquid, boiling at 38°C, and should not be stored for long periods of time (Bhopal accident, India). India has developed a process for the preparation of aryl esters of A/-alkyl carbamic acids. Thus l-naphthyl methylcarbamate is prepared by refluxing 1-naphthol with ethyl methylcarbamate and POCl in toluene (60). In 1992, carbaryl production totaled > 11.4 x 10 t(35). Rhc ne-Poulenc, at its Institute, W. Va., facihty is the only carbaryl producer in United States. 

Pigment Red 3 [2425-85-6] 12120 Beta-Naphthol (Toluidine Red) coupling of dia2oti2ed 2-nitto-4-methyl-aniline with 2-naphthol... 

Pigment Red 53, barium salt [5160-02-1] 15585 1 BONA (Ba salt) (Lake Red C) coupling of dia2oti2ed 2-amino-4-methyl-5-chloroben2enesulfonic acid with 2-naphthol, foUowed by salt formation... 

Thallium trinitrate oxidi2es naphthols and hydroquinone monoethers, respectively, to quinones and 4,4-diaIkoxycyclohexa-2,5-dienones, eg, 4,4-dimethoxy-2-methyl-2,5-cyclohexadienone [57197-11 -2] (108) (111,112). The yield of (108) is 89%. Because the monoacetal is easily converted to the quinone, the yield of 5-hydroxy-l,4-naphthoquinone [481-39-0] is 64%. 

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). 

In mordant dyes, phenols, naphthols, and enolizable carbonyl compounds, such as pyrazolones, are generally the couplers. As a rule, 2 1 metal complexes are formed ia the afterchroming process. A typical example of a mordant dye is Eriochrome Black T (18b) which is made from the important dyestuff iatermediate nitro-l,2,4-acid, 4-amiQO-3-hydroxy-7-nitro-l-naphthalenesulfonic acid [6259-63-8]. Eriochrome Red B [3618-63-1] (49) (Cl Mordant Red 7 Cl 18760) (1, 2,4-acid — l-phenyl-3-methyl-5-pyrazolone) is another example. The equiUbrium of the two tautomeric forms depends on the nature of the solvent. 

Direct Blue 218 had reported sales of 623 t valued at 4.4 million ia 1987. It is produced from Direct Blue 15 (76) by metallizing and elimination of methyl groups from the methoxide to form the copper complex. Direct Blue 15 (76) is prepared by coupling o-dianisidine [119-90-4] to two moles of H-acid (4-amiQO-5-hydroxy-2,7-naphthalenedisulfonic acid) under alkaline pH conditions. Other important direct blues iaclude Direct Blue 80 (74), (9-dianisidine coupled to two moles of R-acid (3-hydroxy-2,7-naphthalenedisulfonic acid [148-75-4]) followed by metallizing to form a bis copper complex, and Direct Blue 22 (77), an asymmetrical disazo dye, prepared by coupling o-dianisidine to Chicago acid [82-47-3] and 2-naphthol. Direct Blue 75 (78) is an example of a trisazo dye represented as metanilic acid — 1,6-Q.eve s acid — 1,6-Q.eve s acid — (alb) Ai-phenyl J-acid. 

Methyl-2-naphthol [26593-50-0] M 158.2, m 118 , pK, -9.7. Crystd from EtOH or ligroin. Sublimed in vacuo. 

Oxygen -I- Methyl Formamide-1- a—Naphthol = Carbaryl + Water (12.2) which yields an economic potential of 39.99 million per year, and... 

Methyl Amine + a-Naphthol Chloroformate = Carbaryl -I- Hydrogen Chloride,... 

Naphthol - N -Ethyl-N -(2-methanesulfonamidoethyl)-2-methyl-l, 4-phenylenediamine Reagent)... 

Dipping solution Dissolve 3 g 1-naphthol in 150 ml methanol and add 1350 ml water. Dissolve 0.5 g potassium disulfite (potassium metabisulfite) in this solution, add 20 ml glacial acetic acid and dissolve 0.5 g iron(II) sulfate THiO followed by 2.2 g N -ethyl-N -(2-methanesulfonamidoethyl)-2-methyl-l,4-phenylenediamine (sesquisulfate, monohydrate) (color developer 3, Merck). Care should be taken at each step that the solution has clarified before adding further components. 

Naphthalene, 216 Naphthalene picrate, 217 Naphthalene sulphonaie ofsodiiim, 218-/ J-Naphthol, 219 Naphthol yellow, 224 /i Naphthyl acetate, 222 /j-Naphthyl methyl ether, 220 /-Nitracetanilide, 153 w-Nitraniline, 154 /-Nitraniline, 153 Nitric acid (fuming), 22 NitroVienzene, 142 w-Nitrobenzoic acid, 200 Nitrogen, qualitative e rimation, 2 quantitative estimation, 13 Nitrophenol, 183 Nitrosohenzene, 146 /-Nitrosodimethylaniline, 157 Niirosoplienol, 159... 

---