O-tert-Butylphenol

Methyl-2-butene Methyl butyl ketone Methyl iso-butyl ketone Methyl tert-butyl ketone Methyl-o-tert butylphenol Methyl butyrate... 

The alkylation of phenol by isobutylene catalyzed by a cation-exchange resin and sulfuric acid at 60-100 °C in a batch reactor, showed that an increase in the concentration of hydrogen ions in the cation-exchange resin from 8 to 24 mmol/1 augmented the conversion of phenol. However, the selectivity, determined as the ratio of obtained o-tert-butylphenol to reacted phenol, initially decreased but afterwards increased [24]. Upon reducing the cationite particle size from 0.63 to 0.004 mm, the conversion of phenol increased. Nonetheless, a further decrease in particle size did not affect the reaction rate. 

The simulations show (Fig. 2) that with the substrate diffusion model (eqs. 18-20) it is possible to explain the presence of a sh mt and to model the effects of external mass transfer of the organic reaction components on the selectivity. But it was not possible with this model to simulate the observed concentration curves for the hydrogenation of o-tert.butylphenol (see Fig. 4) This is easily understood if one calculates Da for the hydrogenation of o-alkylphenols on palladium catalyst (< 10 jun) using appropriate correlations. In the investigated temperature-pressure region, these Da numbers are of the magnitude 10 4 to 10-5, Under... 

Fig. 4 Hydrogenation of o-tert.butylphenol on palladium. Curves simulated with desorption model (eqs. 24-26).

Among the tertiary-butyl phenols, the o- and p-derivatives and 2,6-di-tert-butylphenol are commerically important. They are used in the production of antioxidants. o-tert-Butylphenol and 2,6-di-tert-butylphenol are produced by alkylation of phenol with isobutene at a reaction temperature of 100 °C in the presence of aluminum phenolate as catalyst. 

Preparation by Friedel-Crafts acylation of o-tert-butylphenol with benzoyl chloride in ethylene dichloride in the presence of titanium tetrachloride, first with ice cooling, then for 5 h at r.t. (44%) [816]. 

The concept of using group I metal initiators was applied in order to minimize the toxicity generated by heavy metal residues in the end product PLAs when using metals like aluminum, tin, and lanthanides as initiators. In recent years, dinuclear lithium and macro-aggregates with phenolate ligands have attracted substantial interest, mainly due to uncommon strucmral feamres and their ability to catalyze formation of polyester and various other polymeric materials via ROP [28]. A series of lithium complexes supported with 2, 2-ethylidene-bis (4, 6-di-tert-butylphenol) (EDBP-H2) 2-6, (Scheme 6) are excellent initiators for the ROP of L-lactide in CH2CI2 at 0 °C and 25 °C [33-35]. In this case, the PDIs of the obtained PLAs were quite narrow (1.04—1.14) and a Unear relationship between and the monomer-to-initiator ratio ([M]o/[I]o) existed at 0 °C. Dimeric complexes 4 and 6 were the... 

Fig.1. Two-stage polymerization of methyl methacrylate (MMA) in CH2CI2 at room temperature with the enolatealuminum porphyrin (2, R=Me)-methylaluminum bis(2,4,6-tri-tert-butylphenolate) (3f) (1.0 1.0) system. GPC profiles of the polymers formed at the first stage (I) [MMA]o/[l (X=Me)]o=50, 100% conversion Mn=7,000, Mw/Mn= 1.12 and the second stage (II) [MMA]o/[2]q=200, 100% conversion Mn=47,600,Mw/Mn= 1.05...

Fig. 16. NMR profiles in CD2CI2 at 25 °C of methyl methacrylate (MMA)-Lewis acid mixtures. Relationships between the chemical shift of the C=0 signal of MMA and the mole ratio of Lewis acid to MMA Lewis acids triphenylboron ( ), tris(pentafluorophenyl)boron ( ), tri-n-butylboron (A), triphenylaluminum (O), and methylaluminum bis(2,4,6-tri-tert-butylphenolate) ( )...

Fig. 27. Polymerization of 1,2-epoxypropane (PO) by the alcoholatealuminum porphyrin (16, n=10)-methylaluminum bis(2,4,6-tri-tert-butylphenolate) (3f) system. Relationship between Mn ( ) [Mw/Mn (O)] of the polymer and conversion...

The redox noninnocence of the 2-mercapto-3,5-di-tert-butylaniline ligand has recently been investigated with nF ions. The spectroelectrochemistry of the complex displays a range of electron transfers where the monocation, the neutral species, and the mono- and dianions have been characterized. In a related manner, Wieghardt and coworkers have reported the first example of a stable N, O-coordinated o-iminobenzoquinone via air oxidation of the initial nF complex with 2-anilino-4,6-di-tert-butylphenol (94). The analogous o-iminobenzosemiquinonate 7r-radical complex was also isolated for this system and earlier for the bis-(o-immobenzosemiquinonate)nickel(II) complex. ... 

UTD-1 may have catalytic properties such as those observed with the commercially sucsessfiil titanium silicahte TS-1 catalyst which is effective for alkane and alkene o ddation as well as phenol hydroxylation in the presence of hydrogen peroxide [8]. The large pore nature of Ti-UTD-1 should allow the reaction of large substrates such as 2,6-di-tert-butylphenol as well as the use of oxidants such as tert-butylhydroperoxide (t-BHP) which are too large for the medium pore TS-1 zeolite. Ti-UTD-1 offers an opportunity to examine reactivity in pore space greater than Ti-beta but less than the mesoporous Ti-MCM-41 type molecular sieves. In the present study results for the peroxide based oxidation of cyclohexane, cyclohexene and 2,6-di-tert-butylphenol will be presented. 

MW-UV irradiation of 4-tert-butylphenol (4TBP) has also been investigated [137]. Photolysis of this compound furnished 4, 5-di-tert-butyl-2-hydroxydiphenyl ether (ortho-O) and 5,5 -di-tert-butylbiphenyl-2,2 -diol (ortho-ortho), and 2TBP as... 

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