4-tcrt-Butylphenol

The addition of trichlorotitanium 4-tcrt-butylphenolate 89 to phthalaldehyde gives the intermediate 90, which nndergoes a ring-chain tautomerism to afford the cyclic isomer 91. The latter reacts with the second molecule of 89 to yield the final product 92 via replacement of the acetalic OH group by the p-t-butylphenol moiety (equation 36). 

DBU), l,5-diazabicyclo[4.3.0]non-5-ene (DBN), and N, N-dimethylaminopyridine (DMAP) afforded polyether diols containing BPA moiety.It was shown by MALDI-TOF spectrometry and and NMR spectroscopies that the product obtained from 4-tcrt-butylphenol and PC at 150 °C contained some amount of oligomers with carbonate linkages. The authors suggested that phenols were ionized by an organic base to form an active phenol anion which attacked cyclic carbonate monomer to generate intermediate ions that could farther capture proton and react with phenol itself to yield polyether or poly(ether-carbonate). 

Trisacetylacetonecobalt(III) oxidises phenols to phenoxyl radicals at 71-120 °C in chlorobenzene with simple second-order kinetics, E = 33 kcal.mole" and AS = 13.6 eu) . When 2,4,6-tcrt-butylphenol was employed, the characteristic ESR spectrum of the phenoxyl radical was obtained with an intensity corresponding to almost quantitative conversion, viz. 

Similar methodology also provides a convenient synthesis of 2-dibenzo-furanol. Treatment of the 2,2 -biphenyldiol 208, (Scheme 52), readily available by oxidative coupling of 2,4-di-tcrt-butylphenol, with an excess of bromine in methanol affords the l-bromo-2-methoxydibenzofuran 209. This undergoes demethylation, debromination, and debutylation on treatment with aluminum chloride in boiling toluene and furnishes 2-dibenzofuranol (210). 

Reaction calorimetry provides useful insights here even if direct enthalpy of formation measurements are absent. Liquid phase isomerization of the o- to p-tcrt-butylphenol has been shown to be exothermic hy 16.9 1.6 kJ mol [T. N. Nesterova, S. P. Verevkin, T. N. Malova and V. A. Pil shchikov, Zh. Prikl. Khim., 58, 827 (1985) Chem. Abstr., 103, 159918x (1985)] while the p- to m-isomerization in both the Uquid and gas phase is exothermic by ca 1 kJ mol [cf. V. A. Pil shchikov, T. N. Nesterova and A. M. Rozhnov, J. Appl. Chem. USSR, 54, 1765... 

A comparison of performance was carried out of DA-UVD and ELD for the determination of trace amounts of phenolic antioxidants, such as BHA (31), 2-tert-butylphenol, 2-tcrt-butyl-4-methylphenol, PG (33a) and OG (33b). The LOD were lower and the linearity ranges wider for ELD than UVD °. ... 

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 soile-up, and produces no ond streams/ waste- and by-products [196], Nickelhydroxide electrode has been applied to the oxidation of primary alcohols to adds 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-tcrt-butyldiphenoquinone, of 2-(benzylideneamino)-phenols to 2-phenyloxazols, of 1,1-dialkylhydrazines to tetraalkyltetrazenes. For details the reader is referred to Ref. [195]. 

Many stable radicals are known and the commercial use of hindered phenols such as 2,4,6-tri-tert-butylphenol or 2,5-di-tcrt-butylhydroxytoluene (BHT) as antioxidants in food and the similar function of vitamin E (a-tocopherol) in cell tissues is based on their ability to form stable free radicals of the type found in oxidative coupling reactions. 

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