Hydroxylation of naphthalene

Acid-cataly2ed hydroxylation of naphthalene with 90% hydrogen peroxide gives either 1-naphthol or 2-naphthiol at a 98% yield, depending on the acidity of the system and the solvent used. In anhydrous hydrogen fluoride or 70% HF—30% pyridine solution at — 10 to + 20°C, 1-naphthol is the product formed in > 98% selectivity. In contrast, 2-naphthol is obtained in hydroxylation in super acid (HF—BF, HF—SbF, HF—TaF, FSO H—SbF ) solution at — 60 to — 78°C in > 98% selectivity (57). Of the three commercial methods of manufacture, the pressure hydrolysis of 1-naphthaleneamine with aqueous sulfuric acid at 180°C has been abandoned, at least in the United States. The caustic fusion of sodium 1-naphthalenesulfonate with 50 wt % aqueous sodium hydroxide at ca 290°C followed by the neutralization gives 1-naphthalenol in a ca 90% yield. 

Uniquely regioselective hydroxylation of naphthalene was also achieved in acidic systems.778 Regioselectivity was found to depend markedly on the acidity of the system and the solvent used ... 

The intermediacy of arene oxides in these systems has been firmly established by subsequent mechanistic studies.658"668 Nonenzymatic rearrangement of 3,4-toluene-4-2H oxide gave 4-hydroxytoluene with the same amount of deuterium retention (in the 3-position) as that observed in the enzymatic hydroxyla-tion of toluene-4-2H by liver microsomes 658 1,2-Naphthalene oxide could actually be isolated as the initial product of the enzymatic hydroxylation of naphthalene.659... 

Metelitsa et al.6S3 recently reported the hydroxylation of naphthalene to a-naphthol with Mo(CO)6-02 at 75° to 95°C in acetonitrile solutions. Oxygen activation by the (Ci0H8)Mo(CO)3 complex was suggested ... 

Thus, the substituted heteropolyanion is stable and active even in the presence of oxidants such as /-BuOOH or PhIO. Note that the heteropolyanion is unstable with respect to hydrogen peroxide. Based on the high stability, TMSP can be used for alkane hydroxylation [67b]. Mansuy et al. have reported that P2Wn06i (Mn3+ Br)8 is oxidation resistant and more active for the epoxidation of cyclooctene with PhIO than those containing Fe3+, Co2+, Ni2+, or Cu2+ [68]. The oxygenations of cyclohexane, adamantane, and heptane and the hydroxylation of naphthalene, are also catalyzed by TMSP. 

Figure 2.7 Hydroxylation of naphthalene using Sn-mesoporous materials...

Hydroxylation of naphthalene. Reaction of naphthalene with H2O2 (90%) in HF or in HF (70%)/pyridinc (30%) at -10° to 20° gives mixtures of naphthols in 26-43% yield in which 1-naphthol is the major product. If the reaction is conducted in a su-pcracid (HF/SbFs, HF/BF.i), 2-naphthol is obtained almost exclusively. The difference is... 

Olah 0t al. have previously studied the acid-catalyzed hydroxylation of naphthalene with a number of systems, inciuding 90% hydrogen peroxide, and reported that high regioselectivity can be obtained depending upon the acidity of the catalyst system and solvent used. 

D. M. Jerina, J. W. Daly, B. Witkop, S. Zaltzman-Nirenberg, and S. Udenfriend (1969), 1,2-Naphthalene oxide as an intermediate in the microsomal hydroxylation of naphthalene. Biochemistry 9,147-156. 

Enzymatic oxidation of naphthalene by bacteria proceeds by way of the intermediate ciy-diol shown. Which prochiral faces of C-1 and C-2 of naphthalene are hydroxylated in this process ... 

Bunce NJ, L Liu, J Zhu, DA Lane (1997) Reaction of naphthalene and its derivatives with hydroxyl radicals in the gas phase. Environ Sci Technol 31 2252-2259. 

Chaudhari et al. (277) had observed a linear dependence of H2O2 selectivity on Ti content in Ti-MCM-41 in the hydroxylation of 1-naphthol to 1,2-dihydroxy naphthalene with aqueous H202 (Fig. 47). Both XAS and EPR results had indicated the presence of mainly the tripodal titanium sites on Ti-MCM-41. As a consequence of the large surface area of the material, these sites are well dispersed, leading to the linear dependence of catalytic activity on Ti content. 

Boyd, D.R., McMordie, R.A S., Sharma, N.D., Dalton, H., Williams, P. and Jenkins, R.O., Stereospecific benzylic hydroxylation of bicyclic alkenes by Pseudomonas putida isolation of (+)-/ -l-hydroxy-l,2-dihydronaphthalene, an arene hydrate of naphthalene from metabolism of... 

Kinetic parameters of metabolism of fluorinated analogues of propanolol by cytochrome enzyme (recombinant CYP1A2) have been determined. They clearly indicate that the A-dealkylation process was 10-fold lower for the N—CH2CF3 compound with respect to propanolol itself. Hydroxylation of the naphthalene ring process is not observed in the case of propanolol but it becomes the major process with the fluoro analogue (Figure 3.13)." The same decreased metabohsm trend has also been observed with lower pKa values for CYP2D6 cytochrome enzyme." ... 

The oxidation of naphthalene was one of the earliest examples of an epoxide as an intermediate in aromatic hydroxylation. The epoxide can rearrange nonenzymatically to yield predominantly 1-naph-thol, interact with the enzyme epoxide hydrolase to yield the dihydrodiol, or interact with glutathione S-transferase to yield the glutathione conjugate, which is ultimately metabolized to a mer-capturic add. 

When the hydroxylation reaction of naphthalene was carried out with Fe3+ and H202 (the Fenton reaction), which produce the OH radical, the main products... 

C. tert-Butyl-tert-ootylamine. In a dry 500-nL, three-necked flask equipped with a mechanical stirrer, addition funnel, and nitrogen Inlet are placed 25.6 g (0.20 mol) of naphthalene, 250 nt of dry tetrahydrofuran (THF), and 10.8 g (0.47 mol) of sodium pieces. The mixture is stirred at room temperature for 30 min. To the blue-green sodium naphthalenide solution is added the hydroxyl amine mixture (Note 10) in 50 iri. of THF over 20 m1n (Caution exothermic reaction). The mixture is stirred for 2.5 hr at room... 

R. E. Parales, D. T. Gibson, H. Eklund, and S. Ramaswamy, Structure of an aromatic ring-hydroxyl-dioxygenase-naphthalene-... 

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