Dihydroxy naphthalene

Chicago acid (l,8-dihydroxy-naphthalene-2,4- disulfomc acid) [82-47-3... 

Chromotropic acid (1,8-dihydroxy naphthalene- 3,6-disulfonic acid)[148-25-4... 

Naphthalene-3,6-disulfonic acid, l,8-dihydroxy-2-(2-thiazolylazo)-analytical uses, 6, 328 Naphthalenes... 

More recently, Kim et al. synthesized dendritic [n] pseudorotaxane based on the stable charge-transfer complex formation inside cucurbit[8]uril (CB[8j) (Fig. 17) [59]. Reaction of triply branched molecule 47 containing an electron deficient bipyridinium unit on each branch, and three equiv of CB[8] forms branched [4] pseudorotaxane 48 which has been characterized by NMR and ESI mass spectrometry. Addition of three equivalents of electron-rich dihydrox-ynaphthalene 49 produces branched [4]rotaxane 50, which is stabilized by charge-transfer interactions between the bipyridinium unit and dihydroxy-naphthalene inside CB[8]. No dethreading of CB[8] is observed in solution. Reaction of [4] pseudorotaxane 48 with three equiv of triply branched molecule 51 having an electron donor unit on one arm and CB[6] threaded on a diaminobutane unit on each of two remaining arms produced dendritic [ 10] pseudorotaxane 52 which may be considered to be a second generation dendritic pseudorotaxane. 

Brown HT (El55, Cl Food Brown 3, Chocolate brown) is a bis azo dye, with the chemical name disodium 4,4 -(2,4-dihydroxy-5-hydroxymethyl-l,3-phenylene-bisazo) di(naphthalene-l-sulfonate). The calcium and potassium salts are also permitted. Brown HT is a reddish-brown powder or granules, soluble in water, insoluble in ethanol, with a maximum absorption in water at 460 nm, pH 7, = 403). 

Eaton RW, PJ Chapman (1992) Bacterial metabolism of naphthalene construction and use of recombinant bacteria to study ring cleavage of 1,2-dihydroxy naphthalene and subsequent reactions. J Bacteriol 174 7542-7554. 

Kuhm AE, A Stolz, K-L Ngai, H-J Knackmuss (1991) Purification and characterization of a 1,2-dihydroxy-naphthalene dioxygenase from a bacterium that degrades naphthalenesulfonic acids. J Bacteriol 173 3795-3802. 

Condensation of benzotriazole with 2-carboxybenzaldehyde gives 3-(benzotriazol-l-yl)phthalide 795 (Scheme 127). The anion derived from phthalide 795 adds to the ft-carbon atom of a,( -unsaturated carbonyl compounds E to produce anion 796 that by intramolecular nucleophilic attack on the phthalide carbonyl group is converted to anion 797. Spontaneous expulsion of benzotriazole from molecules 797 followed by aromatization leads to 1,4-dihydroxy-naphthalenes 798 <1997SC3951>. 

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. 

The suitability of ethers derived from 1,4-dihydroxy-1,2,3,4-tetrahydro-naphthalene (DHTN) in the design of polymers susceptible to catalyzed thermolytic cleavage is demonstrated by the behavior of its bis-p-nitrophenyl ether derivative upon treatment by a trace of acid. Figure 2, curve A, shows the H-NMR spectrum of the starting compound, while curve B shows the product which is obtained upon addition of triflic acid. It is readily seen from these spectra that quantitative cleavage into naphthalene and p-nitrophenol is obtained as elimination occurs easily to afford the aromatic product. The driving force in this reaction is the facile aroma-tization which produces naphthalene. 

Figure 13.21 Mononuclear non-haem iron enzymes from each of the five families in structures which are poised for attack by 02. (a) The extradiol-cleaving catechol dioxygenase, 2,3-dihydroxy-biphenyl 1,2-dioxygenase (b) the Rieske dioxygenase, naphthalene 1,2-dioxygenase (c) isopenicillin N-synthase (d) the ot-ketoglutarate dependent enzyme clavaminate synthase and (e) the pterin-dependent phenylalanine hydroxylase. (From Koehntop et al., 2005. With kind permission of Springer Science and Business Media.)...

Wilson and Madsen [152] used the metabolic pathway for bacterial naphthalene oxidation as a guide for selecting l,2-dihydroxy-l,2-dihydronaphthalene as a unique transient intermediary metabolite whose presence in samples from a contaminated field site would indicate active in situ naphthalene biodegradation (Fig. 26). Naphthalene is a component of a variety of pollutant mixtures. It is the major constituent of coal tar [345], the pure compound was commonly used as a moth repellant and insecticide [345], and it is a predominant constituent of the fraction of crude oil used to produce diesel and jet fuels [346]. Prior studies at a coal tar-contaminated field site have focused upon contaminant transport [10,347], the presence of naphthalene catabolic genes [348, 349], and non-metabolite-based in situ contaminant biodegradation [343]. 

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). 

In a static-culture-flask screening test, naphthalene (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. After 7 d, 100% biodegradation with rapid adaptation was observed (Tabak et al, 1981). In freshwater sediments, naphthalene biodegraded to c/5-1,2-dihydroxy-1,2-dihydronaphthalene, 1-naphthol, salicylic acid, and catechol. 

Jerina, D.M., Daly, J.W., Jeffrey, A.M., and Gibson, D.T. cis-l,2-Dihydroxy-l,2-dihydronaphthalene abacterial metabolite from naphthalene, Arch. Biochem. Biophys., 142 394-396, 1971. 

In a similar approach, monopropargyl derivatives of both catechol 159 and 2,3-dihydroxy naphthalene 160 were cyclized to the corresponding alkylidene benzo- and naphthodioxanes 161 and 162 in DMF in the presence of PdCl2(PPh3)2 as the catalyst (Scheme 13). The OTijfc-cyclization was observed only for the catechol with R = = H. 

HO.C10H2(NO2)4.OH mw 340.16, N 16.47% yel crysts (from acetic acid), mp 227° with expl decompn was prepd by adding dropwise fuming HNO3 to 2,7-dihydroxy-naphthalene in acetic acid (Ref 2). No other expl props were reported... 

Di(4-nitrophenylazo)-2,7-dihydroxy-nophtbalene. See l,8-Bis(4-nitrophenyIazo)-2,7-dihydroxy-naphthalene in Vol 2, p B153-L... 

Di (4-nitrophenylazo)-2,7-dihydroxynaph-thalene see 1,8-Bis (4-nitrophenylazo)-2,7-dihydroxy naphthalene 2 B1S3... 

---