4-Methyl-2,6-di-tert-butyl phenol

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).

Synonyms/Trade Names BHT Butylated hydroxytoluene Dibutylated hydroxytoluene 4-Methyl-2,6-di-tert-butyl phenol ... 

Tetrahydrofuran (THF, tetramethylene oxide, diethylene oxide, 1,4-epoxybutane, tetrahydrofurane, oxoiane) is an industrial solvent widely recognized for its unique combination of useful properties. DuPont THF is better than 99.9% pure with a small (0.025-0.040 wt %) amount of butylated hydroxytoluene (BHT, 4-methyl-2,6-di-tert-butyl phenol) added as an antioxidant. Tetrahydrofuran is a cycloaliphatic ether and is not "photochemically reactive" as defined in Section k of Los Angeles County s Rule 66 (equivalent to Rule 442 of the Southern California Air Pollution Controi District). THF has an ethereal odor. 

This rearrangement proceeds via a 2,3-peroxy radical mechanism4,5 24. Radicals are probable intermediates as these reactions are initiated or accelerated by light or free radical sources (benzyl peroxides, tert-butyl hyponitrite) 2 6, are inhibited by radical scavengers (4-methyl-2,6-di-/ert-butyl phenol)6,7, and display ESR signals of allyl peroxy radicals7-9. 

Synonyms 2,6-di-fert-butyl-i-hydroxy-4-methylbenzene 2,6-di-tert-butyl-4-methylphenol 3,5-di-tert-butyl-4-hydroxytoluene 4-hydroxy-3,5-di-terf-butyltoluene BHT butylhydroxytoluene dibutylated hydroxytoluene butylated hydroxytoluene di-n-butyl hydroxytoluene 4-methyl-2,6-di-t-butyl-phenol 2,6-bis(i,i-dimethylethyl)-4-methylphenol Annulex BHT Antracine 8 Catalin CAO-3 Dalpac DBPC Embanox BHT Hydagen DEO Impruvol lonol CP Sustane Tenox BHT Topanol OC and o Vianol di-ferf-butyl-p-cresol bis(i,i-dimethylethyl)-4-methylphenol Topanol... 

Oxidation of 2,6-di(tert-butyl)phenol (23), both ortfjo-positions of which are blocked by the bulky tert-butyl groups, was effected with 4 equivalents of methyl(trifluoromethyl)dioxirane (553) at 0°C for 1 min to afford three oxygenated products (554, 74 and 555) in 4, 24 and 70% yields, respectively. Dimethyldioxirane-promoted oxidation of 23 required much longer reaction time (48 h) to yield the... 

A complication in the preparation of compounds having sec- and tert-alkyl groups in the 2- and in the 4-positions is their vulnerability to thermal dealkylation with acidic catalysts, particularly with 1% oleum in the range 160-200°C, and, as has been mentioned, to aluminium phenoxide when this is used at high temperature (ref.12). Indeed above 250°C all sec- and tert- groups are eliminated from alkylated phenols. The role of thermal dealkylation has been mentioned for the preparation of nonylphenol from dinonylphenol. In the case of 5-methyl-2,4-di-tert-butylphenol and 4-methyl-2,6-di-tert-butylphenol resulting from the tert-butylation of 3-methyl and 4-methylphenol mixtures, the former... 

Figure 5.13 Separation of phenolic antioxidants by thin-layer chromatography. Solvent benzene development distance 15 cm indicators (a) borate buffer (b) 0.1% 2,6-dichloro quinonechlorimide in methanol. 1 = hydroquinone monobenzyl ether 2 = 2,6-di-rerr-butyl-phenol 3 = 2,6-di-tert-butyl-4-methyl-phenol 4 = 2,6-di-tcrt-butyl-a-methoxy-4-methyl-phenol 5 = 2-a-methyl-cyclohexyl-4, 6-dimethyl-phenol 6 = butylated hydroxyanisole 7 = butylated hydroxy toluene 8 = 4,4"-bis (2,6-di-terf-butyl-phenol) 9 = 2,2"-methylene-bis (4-methyl-6-terf-butyl-phenol) 10 = 2,2"-methylene-bis (4-ethyl-6-fert-butyl-phenol) Reproduced from Kreiner and Warner, Journal of Chromatography [119]...

Lewis, M. A. Graff Yoerg, D. Bolton, J. L. Thompson, J. A. Alkylation of 2 -deoxy-nucleosides and DNA by quinone methides derived from 2,6-di-tert-butyl-4-methyl-phenol. Chem. Res. Toxicol. 1996, 9, 1368-1374. 

Phenol, 2-6-di-tert-butyl-4-methyl 0 Phenol, 3-[2-(3-hydroxy-4 -methoxy-pheny 1 )-ethyl]-5-methoxy PI ... 

Fig. 37. Polymerization of propylene oxide (PO) initiated with the (TPP)AlCl (l,X=Cl)-2-pro-panol (2-PrOH) system in the presence of methylaluminum bis(2,6-di-tert-butyl-4-methyl-phenolate) (3e) ([2-PrOH]o/[PO]o/[l]o=9/200/l) in CH2CI2 at rt. Relationship between p/ TPP ( ) [Mw/Mn (O)] at 100% conversion and the initial mole ratio [3e]o/[l]o-l p and ATtpp Numbers of the molecules of the produced polymer and initiator 1, respectively...

The BBrs reaction with 1. l-dimethoxy-2.4.6-di-tert-butyl-4-(4 -methoxyphenyl)-X -phosphorin 200 leads to cleavage of both methoxy groups in addition to the methoxy group at the phosphorus, the 4 -methoxy group is attacked. The 2-hydro-4-(4 -hydroxyphenyl)-phosphinic acid methyl ester 201 can be methylated with methyl iodide in methanol/sodium methylate at the phenolic group, leading to 202, which can also be prepared by hydrogen peroxide oxidation of 2.6-di-tert-butyl-4-(4 -methoxy phenyl)-X -phosphorin 204 to 203, followed by diazomethane methylation (see Table 13, p. 61). 

Methyl-l-phenyl-4,5-dihydro- -1-oxid E2, 46 aus Isopren/Dichlor-phenyl-phosphan und 2,6-Di-tert.-butyl-4-methyl-phenol E2, 30 3-Mcthyl-l-tetradecyl-4,5-dihydro- -1-oxid E2,... 

A simple, rapid, and reliable viscometric technique for evaluating the protective capacity of commercially available materials as inhibitors of ozone-induced polymer chain scission has been described (1). This work included the results of an evaluation of several chemicals such as A,A -di-sec-butyl-p-phenylenediamine, nickel dibutyl di-thiocarbamate, l-(m-aminophenyl)-2,5-dimethylpyrrole, and 2,6-di-tert-butyl-4-methyl-phenol as antiozonants A,A -di-sec-butyl-p-phenylenediamine exhibited superior inhibiting characteristics. However, because of the potential toxic effects and relatively high vapor pressure of this chemical, its use is considered impractical. 

Sterically hindered phenols react with nitric oxide under basic conditions to give either cyclohexadienone diazenium diolates or oximates. Phenols with 2,6-di-tert-butyl and 4-methyl (butylated hydroxytoluene, BHT), 4-ethyl or 4-methoxymethyl substituents yield the corresponding 2,6-di-tert-butyl-2,5-cyclohexadienone-4-alkyl-4-diazenium diolate salts (equation 58)". ... 

Co(salen)-catalyzed oxidation of phenols with fert-butyl hydroperoxide in CH2CI2 at room temperature provides predominantly tert-butylperoxylated products . On catalytic oxidation of 2,6-di(tert-butyl)-4-acetylphenol oxime O-methyl ether (261), both o- and p-(ferf-butylperoxy)quinol ethers (262 and 263) were obtained in 8.1 and 87.3% yields, respectively. On the other hand, catalytic oxidation of 264 provided the corresponding o- and p-quinol ethers (265 and 266) in 91.1 and 6.8% yields, respectively (Scheme 56). The remarkable difference of the o/p ratio in the reactions of 261 and 264 reflects clearly a combination of both steric and electronic factors. 

The reactions which can occur with sterically hindered phenols in the presence of 102 and a sensitizer are shown on the example of 2,6-di-tert-butyl-4-methyl-phenol XXIV in Scheme 13. It may be expected that the oxidation of XXIV by the excited sensitizer proceeds to phenoxyl XXV, or that phenol XXIV is attacked by 02 giving either again phenoxyl XXV or, by the 1,4-addition, endoperoxide CXIII, which is transferred to hydroperoxycyclohexadienone CXIV160, The latter compound may also originate via biradical CXV, as stated in161 (Scheme 13). 

The experimental studies on the phenolic lignin model compounds (4-propyl-guaiacol, eugenol, isoeugenol, coniferyl alcohol, coniferyl aldehyde and 4-allyl-2,6-dimethoxyphenol) demonstrated that these compounds had more active antioxidants activity than the commercial inhibitor (2,6-di-tert-butyl-4-methyl-phenol) BHT during peroxidation of styrene in chlorobenzene initiated by... 

Cholesteryl chloroformate AnhydrousTHF Anhydrous triethylamine 2,6 -di- tert-butyl- 4 -methyl-phenol (BHT)... 

Dobies [35] has described detailed procedures for determining various antioxidants in PE and PP films. A feature of this method is that it requires only a small polymer sample (5 g) for the determination of down to 0.02% antioxidant compared to sample sizes of up to 1 kg in previously reported procedures. They describe the extraction procedure used for isolating the antioxidants from the polyolefins, the TLC separation of various antioxidants used industrially, and a quantitative determination of the antioxidant to detect 0.02-0.20% of an antioxidant by the use of the double beam scanning densitometer. The six antioxidants he studied were 4,4 -butylidene (2-tert-butyl-5-methyl)phenol 4,4-thiobis(6-tcft-butyl-m-cresol) pentaerythritol tetrakis(3,5-di- er -butyl-4-hydroxyhydrocinnamate) 2,2 -methylenebis(4-methyl-6-tcft-butylphenol) octadecyl (3,5-di-tert-butyl-4-hydroxyphenyl) acetate and 2,6-di-tert-butyl-p-cresol. 

The introduction of substituents containii a-hydrogens into the para-position of phenol sharply changes the EPR spectra splitting on these protons appears. Thus, the radicals of 2,6-di-tert-butyl-4-methyl-phenol (ionol) (IV)... 

UVA 2-hydroxy-4-octyloxybenzophenone 2-hydroxy-4-methoxybenzophenone 2-(2H-benzotriazol-2-yl)-p-cresol 2-(2H-benzotriazole-2-yl)-4,6-di-tert-pentylphenol 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetraethylbutyl)phenol 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazole-2-yl)-phenol 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy) phenol ethyl-2-cyano-3,3-diphenylacrylate HAS 1,3,5-tri-azine-2,4,6-triamine, N,N [1,2-ethane-diyl-bis[[[4,6-bis[butyl-(1,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl] imino]-3,1 -propanediyi] bis[N ,N -dibutyl-N ,N -bis(1,2,2,6,6-pentamethyl-4-piperidinyl)- bis(2,2,6,6-tetramethyl-4-piper-idyl) sebacate 2,2,6,6-tetramethyl-4-piperidinyl stearate N,N -bisformyl-N,N -bis-(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylendiamine alkenes, C20-24-.alpha.-, polymers with maleic anhydride, reaction products with 2,2,6,6-tet-ramethyl-4-piperidinamine 1,6-hexanediamine, N, N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with 2,4-di-ohloro-6-(4-morpholinyl)-1,3,5-triazine 1,6-hexanediamine, N,N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with morpholine-2,4,6-trichloro-1,3,5-triazine reaction products, methylated Phenolic antioxidants ethylene-bis(oxyethylene)-bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate) 2,6,-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5,-triazine-2-ylamino) phenol pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) 2-(1,1 -dimethylethyl)-6-[[3-(1,1 -dimethylethyl)-2-hydroxy-5-methylphenyl] methyl-4-methylphenyl acrylate isotridecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate 2,2 -ethylidenebis (4,6-di-tert-butylphenol) 2,2 -methylenebis(4-ethyl-6-tertbutylphenol) 3,5-bis(1,1-dimethyethyl)-4-hydroxy-benzenepropanoic acid, C13-15 alkyl esters phenol, 4-methyl-, reaction products with dicyclopen-tadiene and isobutene Phosphite trinonylphenol phosphite isodecyl diphenyl phosphite... 

Stabilizers UVA 2(2 -hydroxy-5-methylphenyl)benzotriazole Screener carbon black HAS bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-n-butyl-2-( 3,5-di-tert-bulyl-4-hydroxy-benzyl) malonate Phenolic antioxidants phenol, 4-methyl-, reaction products with dlcyclopentadiene and isobutene 2,6,-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5,-triazine-2-ylamino) phenol 2- (1,1 -dimethylethyl)-6-[[3-(1,1 -dimethylethyl)-2-hydroxy-5-methylphenyl] methyl-4-methylphenyl acrylate isotridecyl- 3- (3,5-di-tert-biAyl-4-hydroxyphenyl) propionate 3,5-bis(1,1-dimethyethyl)-4-hydroxy-benzenepropanoic acid. Cl 3-15 alkyl esters 2,2 -isobutylidenebis(2,4 imethylphenol) Amine nonylated diphenylamine Thiosynergist 2,2 -thiobis(6-tert-butyl-4-methylphenol) 4,6-bis(octylthiomethyl)-o-cresol ... 

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