From naphthols

Triflates of phenols are carbonylated to form aromatic esters by using PhjP[328]. The reaction is 500 times faster if dppp is used[329]. This reaction is a good preparative method for benzoates from phenols and naphthoates (473) from naphthols. Carbonylation of the bis-triflate of axially chiral 1,1 -binaphthyl-2,2 -diol (474) using dppp was claimed to give the monocarboxy-late 475(330]. However, the optically pure dicarboxylate 476 is obtained under similar conditions[331]. The use of 4.4 equiv. of a hindered amine (ethyldiisopropylamine) is crucial for the dicarbonylation. The use of more or less than 4.4 equiv. of the amine gives the monoester 475. 

Hydroxyazo dyes fall into four main categories depending upon the nature of the coupling component used to make them, namely acyclics, phenols, heterocyclics, and naphthols. Those derived from naphthols comprise the largest and most important group commercially. 

Carbazoles from naphthols and aryl hydrazines promoted by sodium bisulfite. 

The absorption maxima of indoanilines dyes derived from naphthols can also be extended well into the near-lR by having strongly electron-withdrawing gronps attached to the qninone ring, as shown in (4.19). 

A phenylboronic acid-mediated synthesis of chromenes from naphthols and 3-methylbut-2-enal features in two short routes to 3-lapachone <99S1875>. 

Metanitranillne orange, nitrotoluidine orange, orange from naphthol A C. 

Figure 1. Schematic representation of solvent effect on proton transfer from naphthols.

Triflates derived from phenols are carbonylated to form aromatic esters by using Pd-Ph3P. The carbonylation of triflates is 500 times faster if DPPP (XLIV) is used [219]. This reaction is a good preparative method of benzoates from phenols and naphthoates from naphthols [220]. Carbonylation of enol triflates derived from ketones and aldehydes affords a,/Cunsaturated esters. The enol triflate in 451 is more reactive than the aryl triflate and the carbonylation proceeds stepwise chemoselectively. At... 

Directions for the preparation of a whole series of iodides of phenols are mentioned In the same patent papers e.g., from -naphthol, phenol7 resorcin, salicylic acid, cresotinic acid7 carra crolf p-isobutylphenol7 o-m-p-isobutyleresal, etc. 

C.I. Acid Blue 138 and C.I. Acid Red 138. Because it is well known that azo dyes derived from naphthol and pyrazolone intermediates exist predominantly in the hydra-zone form, this tautomeric form is given for Acid Yellow 42, Acid Red 151, Acid Red 138, and for the appropriate dyes that follow in this chapter. 

The regiochemistry of the coupling products between aryl radicals and ambident nucleophiles was at the center of the recent work of Pierini et al. [116] (see Table 4). Changing the heteroatom of the nucleophile into a softer one by going down in the periodic table (from naphtholate to naphthylthiolate for instance) leads to an increase in heteroatom substitution C substitution increases when the nucleophile heteroatom is more electronegative or if the aryl moiety of the nucleophile is a more delocalized one. 

The rearrangement of naphthol derivatives is best carried out with 5 mol % of ScfOTOj in toluene at 100 C (Scheme 3). ScfOTflj is also the catalyst of choice for the direct synthesis of the ketones 10 from naphthol and acid chlorides in toluene/nitromethane (yield > 90 %). 

The Kolbe-Schmitt reaction is also used in the preparation of the technically very important 2-hydroxyl-3-naphthoic acid from -naphthol. 

Inks— Mannich bases derived from naphthol and benzotriazole are additives providing dispersant and anticorrosion properties for intaglio printing and ballpoint pen inks, respectively. 

BUCHERER - LE PETIT Naphthol(Naphthylamine)Synthesis Synthesis of naphthylamines from naphthols and naphthots from naphthylamines... 

The most important dyes derived from naphthylamine sulphonic acids and from naphthol sulphonic acids result from coupling them as azo compounds with other rings. This coupling is effected through a diazonium salt made by diazotizing an amine and bringing this di-... 

From the facts that azo-dyes from Schaeffer s acid differ but little in shade and solubility from those obtained from -naphthol, and that simple /3-naphthol azo-compounds on sulphonation always yield derivatives of Schaeffer s acid, and never those of crocein-acidj it may naturally be concluded that the azo-group enters in the same position both in /S-naphthol and in Schaeffer s acid. This is the a-y position. 

Bucherer carbazole synthesis. Formation of carbazoles from naphthols or naphthylamines, aryl-hydrazines, and sodium bisulfite. 

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