Ferf-Butylcatechol

A dinuclear salen complex was investigated as catalyst for the aerobic oxidation of 3,5-di-ferf.-butylcatechol into 3,5-di-teri.-butylquinone in organic and aqueous organic solution. The actual catalyst composition varies in both solvent systems. Formation of a mononuclear species competes with formation of a dinuclear copper(ll) catalyst. The aerobic oxidation of 8 into 9 is 140,000-fold accelerated over background in aqueous methanol, and is about twice as fast as the same reaction in pure methanol. 

Methacrylonitrile [126-98-7] M 67.1, b 90.3°, d 0.800, n 1.4007. n30 1.3954. Washed (to remove inhibitors such as p-ferf-butylcatechol) with satd aq NaHSC>3, 1% NaOH in saturated NaCl and then with saturated NaCl. Dried with CaCl2 and fractionally distd under nitrogen to separate from impurities such as methacrolein and acetone. 

One class of complexes, that of substituted catecholate ligands, has yielded a variety of mono- and di-nuclear MoVI complexes. Mo(CO)6 reacts with the oxidized form of the 3,5-di-ferf-butylcatechol (i.e. 3,5-di-rerr-butyl-l,2-benzoquinone) to yield Mo(dbcat)3 which reacts with 02 to give the dinuclear complex [MoO(dbcat)2]2.373 In contrast, reaction of Mo(CO)6 with 3,4,5,6-tetrachloro-l,2-benzoquinone yields the dinuclear non-oxo complex Mo2(02C6Cl)6.3S7 The complex Mo2Os(phenSQ) has already been discussed.363 This complex... 

A series of catecholate derivatives 189 and 190 were prepared from the parent dichloro complexes by reaction with o-catechol or tetrachloro-o-catechol and Me3N in hot methanol.83 The corresponding reaction with an unsymmetrical catechol, 3,5-di-ferf-butylcatechol produced a mixture of isomers 191a and 191b. The related dioxolene complexes 192 and the amidophenolate complexes 193 were also prepared by the same method. An X-ray crystal structure on the latter complex shows that the phenolate oxygen is trans to the aryl carbon atom. 

New important information about the structure of the intermediate complex was obtained from the X-ray studies of V complex with di-ferf-butylcatecholate [18]. The complex, the structure of which is presented in Figure 4, contains four vanadium ions two are divalent and two trivalent, but they are indistinguishable, thus their oxidation state is 2.5 and the complex can be regarded as existing in a semi-reduced state, similar to the s-r state of FeMoco in the presence of dithionite, which is not sufficiently reduced to activate dinitrogen. 

Styrene [100-42-5] M 104.2, b 41-42 /18mm, 145.2 /760mm, d 0.907, n 1.5469, n s 1.5441. Styrene is difficult to purify and keep pure. Usually contains added inhibitors (such as a trace of hydroquinone). Washed with aqueous NaOH to remove inhibitors (e.g. rm-butanol), then with water, dried for several hours with MgS04 and distd at 25° under reduced pressure in the presence of an inhibitor (such as 0.005% p-ferf-butylcatechol). It can be stored at -78°. It can also be stored and kept anhydrous with Linde type 5A molecular sieves, CaH2, CaS04, BaO or sodium, being fractionally distd, and distd in a vacuum line just before use. Alternatively styrene (and its deuterated derivative) were passed through a neutral alumina column before use [Woon et al. J Am Chem Soc 108 7990 1986 Collman J Am Chem Soc 108 2588 1986]. 

Butadiene is stored in a cool and well-ventilated location separated from combustible and oxidizing substances. Small amounts of stabilizers, such as o-dihydr-oxybenzene, j)-ferf-butylcatechol, or aliphatic mercaptans, are added to prevent its polymerization or peroxides formation. The cylinders are stored vertically and protected against physical damage. 

H. R. Kricheldorf, L. Vakhtangishvili, G. Schwarz, G. Schulz, and R.-R Kruger. Macrocycles 25. Cyclic poly(ether sulfone)s derived from 4-ferf-butylcatechol. Polymer, 44(16) 4471-4480, July 2003. 

Inhibitors (such as 4-ferf-butylcatechol) (306) are usually added to monomers to be stored or transported to prevent premature thermal polymerisation. In precisely-controlled laboratory experiments, it is necessary to remove the inhibitor by distillation. However, industrial processes do not require the removal of inhibitor. Additional amounts of initiator are added to compensate for the presence of inhibitor. 

Simultaneous patch-test reactions to p-tert-hutyl-phenol-formaldehyde resin and p-ferf-butylcatechol have been reported (Estlander et al. 1998), and p-tert-butylcatechol has been shown to be a component in at least some resins based on p-ferf-butylphenol-formal-dehyde (Zimerson and Bruze 1998). This can indicate a connection to other sources of p-ferf-butylcatechol, which is used as an antioxidant (Gellin et al. 1970) and as a stabiliser in different plastic monomers (Macfar-lane et al. 1990). 

Synonyms PTBC 4-ferf-butylcatechol 4-tert-butylpyrocatechol TBC 4-(i,i-dimethylethyl)-i,2-benzenediol tertiary-butylcatechol Uses antioxidant in polyester resins polymerization inhibitor in PVC antioxidant in oil A... 

Ziegler-Natta solution polymerization processes are very sensitive to impurities. Both the monomer and solvent streams must be well purified. Carbonyl and acetylenic impurities, common in crude monomer streams, must be removed along with the common polymerization inhibitor ferf-butylcatechol. Molecular weight control is often accomplished by the addition of chain-transfer agents in certain Ziegler-Natta systems. 

The use of phenols such as ferf-butylcatechol as free-radical scavengers is based on the fact that phenolic hydrogens are readily abstracted by radicals, producing relatively stable phenoxyl radicals that interrupt chain processes of oxidation and polymerization. Alcohols such as cyclohexanol, on the other hand, do not function as radical scavengers. Explain why the two types of molecules differ in their abilities to donate a hydrogen atom to a radical, R. ... 

Write an equation for the reaction involved in the removal of ferf-butylcatechol from styrene by extraction with sodium hydroxide. 

Why is it necessary to remove ferf-butylcatechol from commercially available styrene prior to preparing polystyrene ... 

SCHEME 24.8 Polymerization of epoxides with ZnEt2/l-phenoxy-2-propanol/4-ferf-butylcatechol. 

A new functional model chemistry on catechol dioxygenases has been developed by Funabiki et a/.. " Water-soluble ligands were prepared by sulfonation of tripodal ligands such as TPA and used for catalytic oxygenation of water-soluble catechols such as 4-ferf-butylcatechol, 4-chlorocatechol, and protocatechuic acid (eq. 4). 

Indene-3-carboxylic acid, butadiene, toluene, and a trace of ferf-butylcatechol heated 24 hrs. at 120° in a steel bomb -> l,4,4a,9a-tetrahydro-4a-fluorene-carboxylic acid. Y 81%. F. e., also from esters, s. E. F. Godefroi and L. H. Si-manyi, J. Org. Ghem. 28, 1112 (1963). 

Dinitrophenylhydrazine 2,6-Di-ferf-butylcatechol Dioctyladipate Di(r-octyl)diphenylamine Dioctylphthalate Dioctyl- >-phenylene diamine Dioctylsebacate Dioctadecyldisulfide... 

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