2,6-Di-tert-butylphenols

Chemical D ignations - Synonyms 2,6-Di-tert-butylphenol Chemical Formula 2,6-(t-C4H,),C,H30H. 

The nickel hydroxide electrode resembles in its applications and selectivity the chemical oxidant nickel peroxide. The nickel hydroxide electrode is, however, cheaper, easy to use and in scale-up, and produces no second streams/ waste- and by-products [196], Nickelhydroxide electrode has been applied to the oxidation of primary alcohols to acids or aldehydes, of secondary alcohols to ketones, as well as in the selective oxidation of steroid alcohols, cleavage of vicinal diols, in the oxidation of y-ketocarboxylic acids, of primary amines to nitriles, of 2,6-di-tert-butylphenol to 2,2, 6,6 -tetra-rert-butyldiphenoquinone, of 2-(benzylideneamino)-phenols to 2-phenyloxazols, of 1,1-dialkylhydrazines to tetraalkyltetrazenes. For details the reader is referred to Ref. [195]. 

F. G. Bordwell, X.-M. Zhang. Acidities and Homolytic Bond Dissociation Enthalpies of 4-Substituted-2,6-di-tert-Butylphenols. J. Phys. Org. Chem. 1995, 8, 529-535. 

Merck Kieselgel 60 (Art. 9385) was used. The checkers found that loading the column in this way avoids precipitation of a by-product during column elution. The chromatography removes a few percent of remaining epoxide and 4-bromo-2,6-di-tert-butylphenol. 

Di-tert-butylphenol was obtained from Nacalai Tesque Co. and used without any purification. 

Bromo-2,6-di-tert-butylphenol Phenol, 4-bromo-2,6-di-tert-butyl- (8) Phenol, 4-bromo-2,6-bis(1,1-dimethylethyl)- (9) (1139-52-2)... 

Di-tert-butylphenol Phenol, 2,6-di-tert-butyl- (8) Phenol,... 

Stevels WM, Ankone MJK, DijkstraPJ, Feijen J (1996) A versatile and highly efficient catalyst system for the preparation of polyesters based on lanthanide tris(2,6-di-tert-butylphenolate) s and various alcohols. Macromolecules 29 3332-3333... 

It has long been known (93) that cobalt(II) complexes of phthalocyanines interact with molecular oxygen. The water-soluble tetrasulfonato derivative of the parent phthalocyanine selectively and catalytically oxidizes 2,6-di-tert-butylphenol to the benzoquinone and the dipheno-quinone in both homogeneous solution (94) and when polymer-supported (95). The active intermediate in the catalytic cycle is proposed to be the (as expected) mononuclear dioxygen complex of the cobalt-tetrasulfonatophthalocyanine system (92). It has been proposed that the formation of a peroxo-bridged dinuclear complex is responsible for the deactivation of the cobalt(II)-tetrasulfonatophthalocyanine system, since such a dinuclear system would be unable to further bind and activate dioxygen (96). Such deactivation results, ultimately, in loss of the catalyst and low turnover ratios. 

Fig. 1 Spectra measured 50, 250 and 1000 ps (downwards from the top) upon fs-laser photolysis of 5xl0"3 mol dm"3 2,6-di-tert.-butylphenol (left) or 4-methyl-2,6-di tert.-butyl phenol (right) in pure acetonitrile and in samples containing 1 mol dm"3 water (below).

Fig. 2 Transient spectrum taken in the ns-laser photolysis (15 mJ)of a 02 purged solution of 10"3mol dm"3 4-methyl-2,6-di-tert.-butylphenol in n-butyl chloride taken ( ) 10 ns and (>) 8 s after the pulse. The inset shows the photonity in the transient maxima where the 450 nm curve was threefold amplified (absorption given for I0= 300 mV).

Anodic oxidation of 2,6-di-tert-butylphenols (35) in acetonitrile or acetonitrile-perchloric acid leads to 7-tm-butyl-2-methylbenzoxazoles (36). In the absence of nucleophiles, the initially formed cation 37 adds acetonitrile to give 38, which loses a fert-butyl cation, [Eq. (41)].87... 

In a variation on this theme cobaltphthalocyaninetetrasulfonate (CoPcTs) was bound via the anionic sulfonate groups to styrene-divinylbenzene copolymer latexes containing quaternary ammonium ions.46 The resulting colloidal catalyst was used to effect the autoxidation of 2,6-di-tert-butylphenol in aqueous solution, to the corresponding diphenoquinone (reaction 21). The rate of oxidation was ten times faster than with homogeneous CoPcTs in water. 

Frankfurt OS, Lipchina LP, Bunto TV, Emanuel NM. 1967. [The effect of 4-methyl-2,6-di-tert.-butylphenol (ionol) on liver tumor induction in rats]. Biull Eksp Biol Med 64 86-88. 

Consideration of the benchmark chemicals illustrates this approach. Anthracene and 2,6-di-tert-butylphenol have no hydrolyzable functional groups (i.e., are NLFG compounds), hence they cannot undergo hydrolysis. Trichloroethylene hydrolysis has been reported (Jeffers et al., 1989 Jeffers and Wolfe, 1996), but the measured rate constants imply an environmental half-life at pH 7 and 25°C of 100,000 years. Similarly long half-lives have been calculated for other halogenated ethenes, so that, as a class, hydrolysis can be disregarded for these compounds. 

As examples of the calculation of OH radical reaction rate constants using the method discussed above (Kwok and Atkinson, 1995), the OH radical reaction rate constants for lindane [y-hexachlorocyclohexane cyclo-(-CHCl-)6], trichloroethene (CHC1=CC12), 2,6-di-tert-butylphenol, and chloropyrofos appear below. As the section dealing with OH radical addition to aromatic rings mentions, at present the rate constant for the reaction of the OH radical with anthracene (and other PAH) cannot be estimated with the method of Kwok and Atkinson (1995). In carrying out these calculations, one first must draw the structure of the chemical (the structures are shown in the appendix to Chapter 1). Then one carries out the calculations for each of the OH radical reaction pathways which can occur for that chemical. 

At the same time, there is little advantage in having the alkoxy group in position 4 of 2,6-di-terf-butylphenol, as shown on comparison with the compound substituted in the same position by the methyl group and with 2,6-di-tert-butylphenol itself, a compound with a free position 4 (Ari = 2.69). Different influences of the nature of the substituent in... 

Fluorinated aromatic substrates have been used in the synthesis of fluorinated biaryl derivatives via S l reactions650. Substrates YC6H4Br (Y = F, CF3 or OCF3) were treated with the anions from 2,4-di-ter/-butylphenol, 2,6-di-tert-butylphenol, / ara-methoxyphenol, / 0ra-(trifluoromethoxy)phenol and 2-naphthol leading to the biaryls YC6H4—ArOH by C-arylation at the carbon atom ortho to the deprotonated hydroxyl group (C-l in 2-naphthol), but at the para carbon atom in 2,6-di-terr-butylphenol. 

Other 2,6-disubstituted phenols react in the same manner, provided the substituents are not too large oxidation of phenols with bulky ortho substituents, such as 2,6-di-tert-butylphenol, yields the diphenoquinone as the major product (16) (Reaction 2). 

The oxidation of organic compounds by /<-peroxo complexes has not been studied in any detail. There have been several reports of the decomposition of /<-peroxo complexes containing dipeptide ligands in which the peptide is oxidised. A recent investigation has shown that this involves oxidation of the N-terminal position of the peptide, leading to a coordinated imine . The complex [(bipy)2Co(M-OH)( -02)Co(bipy)2] has recently been reported to catalyse the oxidation of 2,6-di-tert-butylphenol in methanol solution ), but it is not clear if the oxidation is catalysed by thecomplex... 

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