2,4,6-Tri-f-butylphenol

Oxidation of 44 is completely inhibited by the addition of a small amount of 2,4,6-tri-f-butylphenol. Consequently, the oxidation of the Si—Si bond with oxygen displays the following features 1) a Si—Si bond which is either angle-strained or substituted with more than two fluorine atoms is easily oxidized 2) a radical mechanism is operative 3) the insertion of oxygen into the Si—Si bond proceeds stereospecifically . Incorporation of molecular oxygen was also observed in the direct photolysis of the cyclopolysilanes 80 and 81 (equations 88 and 89) . ... 

Preparation.l Dialkyl acetals of DMF are generally prepared by transacetal-ization of the dimethyl or diethyl acetal, but this reaction is not useful in the case of the di-r-butyl acetal. Replacement of one methoxy group of DMF dimethyl acetal occurs on refluxing in f-butyl alcohol conversion to the dw-butyl acetal is effected in the presence of 2,4,6-tri-f-butylphenol (equation I). 

Figure 1. Degree of ionization of various phenols in aqueous DMSO as a function of solvent composition ( ) 2,6-di-isopropylphenol, (o) 2-t-butylphenol, (half-shaded circle) 2,4-di-f-butylphenol, ( ) 2,6-di-f-butylphenol, ( ) 2,6-di-f-butyl-4-methylphenol, (half-shaded square) 2,4,6-tri-f-butylphenol. (Albagli et al., 1973.)...

Becker used Attenburrow Mn02 for the conversion of hindered phenols into quinol ethers. For example, 2,4,6-tri-f-butylphenol is oxidized in benzene to give OH O O... 

Tri-f-butylphenol 1-Naphthol Cu(C17H35COO)2 Mn(C17H35COO)2 Cu(acetylacetonate)2 Cu-porfirine... 

Di-tert-butylphenol (2,4-DTBP) or 2,4-bis(l,l-dimethylethyl)phenol is produced by the alkylation of phenol with isobutylene under acid catalysis using a mole ratio of 2 1 (isobutylene to phenol). The cmde product contains 4-/ f2 -butylphenol, 2,4-di-/ f2 -butylphenol, and 2,4,6-tri-/ f/-butylphenol. The... 

Urethanes analogous to the amides of the previous section undergo similar deprohmation followed by alkylation and condensation reactions. For example, 2,4,6-tri-f-butylphenol may be converted into the corresponding urethane which can be further functionalized (equation 32). A(-C arbomethoxy-3-pyrroline has been converted into both the trail pheromone for the Pharaoh ant and gephyrotoxin 223 by using regiospecific alkylations (Scheme 3). ° Similar approaches were used in the preparation of the natural product supinidine. Piperidines also have been t ylated via the r-B(X -protected amines. ... 

Compounds containing protic hydrogen atoms, e.g., inorganic [5 to 7] and organic acids [8], alcohols [5, 8], thiols [8], and amines [8], add across the B-N multiple bond. The proton is always added to the imino nitrogen atom. Also, these 1,2-additions are controlled by the steric requirements of the substituents of the reactants. For example, H2O will hydrolyze amino-iminoboranes readily, while 2,4,6-tri-f-butylphenol will not react at all [2]. 

Shlyapnikov et al. [929] have reported distillation in vacuo at different temperatures (from 20° to 200°C), with indications of the degree of extraction from 0.02-0.1 g PE for 0.2-2.0% diphenylamine, phenyl-a-naphthylamine (Neozon A), phenyl-jS-naphthylamine (Neozon D), A-phenyl-A -cyclo-hexyl-p-phenylenediamine, A,A -di-/3-naphthyl-p-phenylenediamine, lonol, 2,4,6-tri-f-butylphenol, propyl gallate, a-naphthene, 2,2 -methylenebis(4-methyl-6-f-butylphenol), 2,2 -thiobis(4-methyl-6-f-butylphenol), 2,2 -methylenebis(4-chloro-6-f-butyl-phenol), 2,6-bis(2-hydroxy-3-f-butyl-5 -methylben-zyl)-4-methylphenol, and Tinuvin 326 reported accuracy of 1-2% using derivative (n = 2) UV spectrophotometry. 

A soln. of 2 moles of 2,4,6-tri-ferf-butylphenol in benzene stirred 2 hrs. at room temp, under Og-free Ng with an aq. soln. of K-ferricyanide and KOH, the alkaline layer removed, the organic layer washed 5 times with water, a suspension of N-acetyl-L-tyrosine in ethyl acetate added with stirring which is continued until a clear greenish yellow soln. results 4-[p-(2-acetylamino-2-carboxyethyl)phenoxy]-2,4,6-tri-ferf-butyl-2,5-cyclohexadien-l-one. Y 77%. F. e. s. T. Matsuura and A. Nishinaga, J. Org. Chem. 27, 3072 (1962). 

Figure 4. Spectral sensitivity data of PMMA and sensitized PMMA obtained by the equipment shown in Figure 3 (A) PMMA (B) PMMA -f- p-teit-butyl benzoic acid (C) PMMA + 2,4-di-tert-butylphenol (D) PMMA + 2,4,6-tri-teit-butyl-...

Bromo-2,6-di-ferf-butylphenol in ether shaken 1 hr. with a soln. of K-ferri-cyanide and KOH in water under Ng -> diphenoquinone. F. e., also with 2,4,6-tri-ferf-butyl-l-phenoxyl, s. K. Ley et al., B. 97, 2670 (1958). 

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