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Naphthalene hydroxylation

Pseudomonas putida P450 MO epPCR/StEP digital image screening enhanced naphthalene hydroxylation/formation of dihydroxy compounds 35, 37... [Pg.332]

Picrates, Many aromatic hydrocarbons (and other classes of organic compounds) form molecular compounds with picric acid, for example, naphthalene picrate CioHg.CgH2(N02)30H. Some picrates, e.g., anthracene picrate, are so unstable as to be decomposed by many, particularly hydroxylic, solvents they therefore cannot be easily recrystaUised. Their preparation may be accomplished in such non-hydroxylic solvents as chloroform, benzene or ether. The picrates of hydrocarbons can be readily separated into their constituents by warming with dilute ammonia solution and filtering (if the hydrocarbon is a solid) through a moist filter paper. The filtrate contains the picric acid as the ammonium salt, and the hydrocarbon is left on the filter paper. [Pg.518]

Bis (trimethyl silyl) peroxide (CH2)3SiOOSi(CH2)3 can be used with triflic acid (CF SO H) and acts as an effective hydroxylating agent of aromatics such as toluene, mesitylene and naphthalene (165). Sodium perborate (a safe and inexpensive commercial chemical) can be used in conjunction with the triflic acid to hydroxylate aromatics (166). [Pg.561]

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. [Pg.497]

Fusion/Hydroxylation. The conversion of arylsulfonic acids to the corresponding hydroxy compound is normally effected by heating with caustic soda (caustic fusion). The primary examples are P-naphthol in the naphthalene series and resorcinol in the benzene series further examples are m- am in oph en o1 from metanilic acid and diethyl-y -arninophenol from /V,/V-diethy1metani1ic acid. In the naphthalene series the hydroxy group is much... [Pg.291]

Many different combinations of carboxyflc acid and hydroxyl groups have been tested to form LCPs. An aromatic stmcture (ben2ene, naphthalene, anthracene, etc) is required that has its functional groups symetricaHy arranged on opposite sides of the molecule. Examples are a 1,4-substituted ben2ene compound or 2,6-substituted naphthalene compound. These monomers are often complex and expensive molecules and account for a significant portion... [Pg.274]

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 ... [Pg.121]

A slightly related reaction involves the amino group of naphthylamines can be replaced by a hydroxyl group by treatment with aqueous bisulfite. The scope is greatly limited the amino group (which may be NH2 or NHR) must be on a naphthalene ring, with very few exceptions. The reaction is reversible (see 13-6), and both the forward and reverse reactions are called the Bucherer reaction. [Pg.861]

Singer S.M. and Allot M.T., Thermoplastic polyurethane elastomer based on a saturated hydroxyl terminated polyol, difunctional aromatic chain extender and 1,5-naphthalene diisocyanate, US Patent 5 599 874, 1997. [Pg.155]

The transformation of arenes in the troposphere has been discussed in detail (Arey 1998). Their destruction can be mediated by reaction with hydroxyl radicals, and from naphthalene a wide range of compounds is produced, including 1- and 2-naphthols, 2-formylcinnamaldehyde, phthalic anhydride, and with less certainty 1,4-naphthoquinone and 2,3-epoxynaphthoquinone. Both 1- and 2-nitronaphthalene were formed through the intervention of NO2 (Bunce et al. 1997). Attention has also been directed to the composition of secondary organic aerosols from the photooxidation of monocyclic aromatic hydrocarbons in the presence of NO (Eorstner et al. 1997) the main products from a range of alkylated aromatics were 2,5-furandione and the 3-methyl and 3-ethyl congeners. [Pg.20]

Considerable attention has been directed to the formation of nitroarenes that may be formed by several mechanisms (a) initial reaction with hydroxyl radicals followed by reactions with nitrate radicals or NO2 and (b) direct reaction with nitrate radicals. The first is important for arenes in the troposphere, whereas the second is a thermal reaction that occurs during combustion of arenes. The kinetics of formation of nitroarenes by gas-phase reaction with N2O5 has been examined for naphthalene (Pitts et al. 1985a) and methylnaphthalenes (Zielinska et al. 1989) biphenyl (Atkinson et al. 1987b,c) acephenanthrylene (Zielinska et al. 1988) and for adsorbed pyrene (Pitts et al. 1985b). Both... [Pg.20]

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. [Pg.39]

The degradation of salicylate to catechol is initiated by monooxygenation accompanied by decarboxylation (salicylate-l-hydroxylase), and two different and independent salicylate hydroxylases have been found in the naphthalene-degrading Pseudomonas stutzeri ANIO (Bosch et al. 1999). Alternatively, in Rhodococcus sp. strain B4, salicylate is hydroxylated to 2,5-dihydroxybenzoate by salicylate-5-hydroxylase (Grand et al. 1992). An alternative occurs for 5-hydroxy- and 5-aminosalicylate in Pseudaminobacter salicylatoxidans in which ring fission is accomplished directly (Hintner et al. 2001). [Pg.425]

Biermann, H.W., MacLeod, H., Atkinson, R., Winer, A.M., Pitts Jr., J.N. (1985) Kinetics of the gas-phase reactions of the hydroxyl radical with naphthalene, phenanthrene and anthracene. Environ. Sci. Technol. 19, 244—248. [Pg.901]

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. [Pg.150]

The benzanthrone system is susceptible to both electrophilic and nucleophilic attack. The most reactive sites towards electrophiles are the 3- and 9-positions, which can be compared with the 4,4 -positions in biphenyl. The 9-position is somewhat deactivated by the carbonyl group, however. Thus, for example, monobromination takes place at the 3-position and further substitution gives 3,9-dibromobenzanthrone. Nitration and benzoylation similarly give rise to the 3-substituted product. The 3-position is in fact peri-hindered (compare naphthalene) so that sulphonation yields the 9-sulphonic acid. Electron withdrawal by the carbonyl group activates the 4- and 6-positions towards nucleophilic attack for example, hydroxylation occurs at these sites. [Pg.302]

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... [Pg.375]

HETE (138) is known to inhibit 5-LO [334]. A group at Revlon created a series of combined 5-LO inhibitors/LT antagonists derived conceptually from the structure of 15-HETE. REV 5901A (139) [335], the best of the series, inhibited 5-HETE release from rat ISN (0.12 //M) and was fairly selective with respect to CO and 12-LO inhibition. The quinoline could be replaced by another lipophilic aromatic group, but potency decreased (naphthalene was 40-fold less potent, and substituted phenyl was 5- to 20-fold less active). Pyridines were active but also less potent 2-pyridyl was only 4-fold less active, while 3- and 4-pyridyl were 20-fold weaker. Ortho-and pnra-substituted phenylene groups were less active. Elimination of the side-chain hydroxyl to the olefin caused a loss of activity, as did the use of shorter alkyl chains. [Pg.33]

Cultures of Bacillus sp. oxidized naphthalene to (-r)-fran5-l,2-dihydro-l,2-dihydroxy-naphthalene. In the presence of reduced nicotinamide adeninedinucleotide phosphate (NADPH2) and ferrous ions, a cell extract oxidized naphthalene to fra/ 5-naphthalenediol (Gibson, 1968). Hydroxylation by pure microbial cultures yielded an unidentified phenol, 1- and 2-hydroxynaphthalene (Smith and Rosazza, 1974). [Pg.824]

Major oxidation products of propanolol and metoprolol formed during ozonation in aqueous solution were investigated by Benner et al. [102, 103]. In the case of propanolol, the main ozonation product is a ring-opened compound with two aldehyde moieties, which results from ozone attack to the naphthalene ring [103]. Formation of aldehyde moieties was also one of the main oxidation routes during metoprolol ozonation, together with hydroxylation [102]. [Pg.115]


See other pages where Naphthalene hydroxylation is mentioned: [Pg.473]    [Pg.233]    [Pg.765]    [Pg.130]    [Pg.473]    [Pg.233]    [Pg.765]    [Pg.130]    [Pg.117]    [Pg.291]    [Pg.76]    [Pg.804]    [Pg.421]    [Pg.26]    [Pg.70]    [Pg.76]    [Pg.400]    [Pg.408]    [Pg.411]    [Pg.426]    [Pg.507]    [Pg.102]    [Pg.392]    [Pg.187]    [Pg.234]    [Pg.154]    [Pg.192]    [Pg.222]    [Pg.20]    [Pg.667]    [Pg.383]    [Pg.196]    [Pg.40]   
See also in sourсe #XX -- [ Pg.494 , Pg.495 ]

See also in sourсe #XX -- [ Pg.664 ]

See also in sourсe #XX -- [ Pg.273 ]




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