2.6- Di-ferf-butyl-4-methylphenol

Di-ferf-butyl-4-methylphenol, see Terbutol Di-ferf-butyl phenol, see 2-Chlorobiphenvl. 4 ... 

The flask in its wire basket is placed in a water bath at 50 °C. After 5 h the polymerization has finished and the color of the solution is then yellow. After cooling to room temperature, 1 ml of 2-propanol is injected and the excess pressure released by insertion of an injection needle.The flask is opened, 0.5 g of 2,6-di-ferf-butyl-4-methylphenol added as stabilizer, and the polymer precipitated in a three-fold volume of methanol.The viscous product is dried in vacuum at 50 °C.The yield is quantitative.The limiting viscosity number is determined in toluene at 25 C. 

RuClj(Hcbx)(cbx) (Hcbx=A-2 -chlorophenyl-2-pyridine-carboxamide). This red-brown material is made from the ligand and RuClj, and its X-ray crystal structure determined (Fig. 1.36). The system RuCl2(Hcbx)(cbx)/Oj/M( butyraldehyde/DCE epoxidised a number of cyclic alkenes efficiently at room temperatures (Table 3.1). Addition of the radical trap 2,6-di-ferf-butyl-4-methylphenol stopped epoxidation reactions altogether, suggesting that a mechanism involving radicals is involved [801],... 

Various aromatic secondary amines, substituted phenols, and pyrazoli-dones (3) that function as traps for the propagating peroxy radicals gave dead-stop induction periods when used at a concentration of 50 p.p.m. An indication of the ease of oxidation of chloroprene is that 50 p.p.m. of 2,6-di-ferf-butyl-4-methylphenol gave an induction period of only 15 minutes, while the same concentration of antioxidant prevented n-hexadecane from oxidizing for 2 hours at 160°C. 

Table 7. Block copolymerization of methacrylonitrile (MAN) with the living prepolymer of methyl methacrylate (MMA) (2) in the presence of methylaluminum bis(2,6-di-ferf-butyl-4-methylphenolate) (3e) ... 

In the presence of methylaluminumbis(2,6-di-ferf-butyl-4-methylphenolate) (3e), the polymerization of PO with 13 took place smoothly even at room temperature, affording a polymer with narrow MWD An example is shown by the polymerization of PO (200 equiv) with 13 without solvent at room temperature. The polymerization proceeded up to 5.1% conversion in 7 d without 3e, while the monomer conversion reached 29.5 and 43.3% in 15 and 70 min, respectively, after the addition of 3e ([3e]o/[13]o=1.0). This corresponds to approximately 3200-times acceleration compared with the polymerization in the absence of 3e. As estimated by GPC (Fig. 32B), the Mw/Mn ratio of the polymer produced at 43.3% conversion was 1.18,and the Mn was 4200, which is close to that expected (5000) when every molecule of 13 forms one polymer molecule (Table 8, run 3). In the presence of 3e, (Salen)AlCl (14) and (Salpn)AlCl (15) were also capable of bringing about the polymerization of PO at room temperature under appropriate conditions, where the degrees of acceleration are estimated to be 1300- and 1200-times, respectively (Table 8, runs 4 and 5). 

Di-ferf-butyl-4-methylphenol see 2,6-di-ferf-butyl-p-cresol. 

Analyte pulse perturbation-chemiluminescence spectroscopy Arthromyces rasomus peroxidase Ascorbic acid Adenosine triphosphate Avalanche photodiode 5-Bromo-4-chloro-3-indolyl 2,6-Di-ferf-butyl-4-methylphenol Bioluminescence Polyoxyethylene (23) dodecanol Bovine serum albumin Critical micelle concentration Calf alkaline phosphatase Continuous-addition-of-reagent Continuous-addition-of-reagent chemiluminescence spectroscopy Catecholamines Catechol... 

H and 13C KIEs were applied to study different types of ene (the Alder-ene) reactions. The reaction of maleic anhydride with allylbenzene was carried out at 175°C in the presence BHT (2,6-di-ferf-butyl-4-methylphenol).88... 

The thermal reactions of l-oxa-l,3-butadienes such as acroleine 2-78 with alkenes such as 2-79 usually need relatively harsh conditions (150°C-250°C) [120]. As a side reaction polymerisation of the a,/l-unsaturated carbonyl compound can take place addition of radical inhibitors such as hydroquinone or 2,6-di-ferf-butyl-4-methylphenol can be helpful in avoiding this unwanted transformation. In the described hetero Diels-Alder reaction the cycloadduct 2-80 was obtained which was then transformed into racemic-/3-santalene 2-81 (Fig. 2-22). 

Oxidation of p-substituted phenols with f-BuOOH catalyzed by heteropoly acids such as H3PMoi2O40-nH2O (283) and H4SiWi2O40-nH2O has been carried out ". When 2,6-di(ferf-butyl)-4-methylphenol (69) was stirred with 80% f-BuOOH in the presence of 283 in AcOH (30 °C, 3 h), it afforded 2,6-di(terr-butyl)-4-(terr-butylperoxy)-4-methyl-2,5-cyclohexadienone (284) and 2,6-di(terf-butyl)-p-benzoquinone (74) in 62 and 13%... 

To a three-necked round-bottomed flask (250 mL) equipped with a reflux condenser, a dropping funnel, and a magnetic stirrer bar, add benzyl alcohol (9.60 mL, 0.09 mol). Add dry THF (60 mL) followed by 2,6-di-ferf-butyl-4-methylphenol (trace, ca.10 mg) and stir until all the solid has dissolved. Finally, triethylamine (19.40 mL, 0.13 mol) is added and the flask cooled to ca. 5°C using an ice-salt bath. 

Di-ferf-butyl-4-methylphenol, 0.75 g, 3.4 mmol harmful, irritant... 

Later, the same group showed that an asymmetric protonation of preformed lithium enolate was possible by a catalytic amount of chiral proton source 23 and stoichiometric amount of an achiral proton source [45]. For instance, when hthium enolate 44, generated from ketene 41 and -BuLi, was treated with 0.2 equiv of 23 followed by slow addition of 0.85 equiv of phenylpropanone, (S)-enriched ketone 45 was obtained with 94% ee (Scheme 4). In this reaction, various achiral proton sources including thiophenol, 2,6-di-ferf-butyl-4-methylphenol, H2O, and pivalic acid were used to provide enantioselectivity higher than 90% ee. The value of the achiral acid must be smaller than that of 45 to accomplish a high level of asymmetric induction. The catalytic cycle shown in Scheme 2 is the possible mechanism of this reaction. 

The naphthalene unit presumably allows enhanced electron delocalization to form a more stable radical. Plant fla vanoids can be good antioxidants. Luteolin is a better antioxidant than 2,6-di-ferf-butyl-4-methylphenol.30 Green tea is a good source of antioxidant flavanoids, one of the... 

It has been reported by Levacher and coworkers that the enantioselective methylation of the lithiated diarylmethane shows good enantioselectivity [102]. In addition, they studied the protonation reaction of lithiated 1 -phenyl- l-(2-py-ridyl)ethane with various proton sources and found that protonation by the use of 2,6-di-ferf-butyl-4-methylphenol in the presence of (-)-sparteine shows good enantioselectivity. Even better selectivity can be obtained in the protonation with chiralM,N-dimethylephedrine [Eqs. (45) and (46)]. Furthermore, as another example of the enantioselective protonation, they have disclosed highly enan-... 

Materials that are not eflfective inhibitors when used alone may nevertheless be able to function as synergists by reacting with an oxidized form of an antioxidant to regenerate it and thus prolong its effectiveness. For example, carbon black forms an effective combination with thiols, disulfides, and elemental sulfur, even though these substances may be almost completely ineffective alone under comparable conditions. Synergistic combinations from a variety of chain terminators and sulfur compounds have been reported. A widely used combination of stabilizers for polyolefins is 2,6-di-ferf-butyl-4-methylphenol (BHT) (Figure 1.41a) with dilauryl thiodipropionate (DLTDP) ... 

Di-ferf-butyl-4-methylphenol, alternatively known as butylated hydroxytoluene (BHT), is used as an antioxidant in foods to "retard spoilage" (Section 8.7). BHT is synthesized industrially from 4-methylphenol by reaction with 2-methylpropene in the... 

---