T-Butyl-benzene

The ratio peaks in figure 11 clearly show the presence of an impurity by the sloping top of the anthracene peak and again this is confirmed unambiguously by the difference in the spectra for the leading and trailing edges of the peak. Further work identified the impurity as t-butyl benzene at a level of about 5%. 

Many partial rate factors are available for the substitution reactions of the other alkylbenzenes, ethylbenzene, i-propylbenzene, and t-butyl-benzene, in addition to the 60 reactions of toluene. The data for these compounds are subject to the same limitations and restrictions described for toluene. The minor uncertainties which do exist are related to the experimental problems involved in the analysis for the small concentration of meta isomer. Rate data for the ortho and para positions are precise (Tables 10, 11, and 12). 

The rate of hydrogen exchange in the aromatic nucleus of t-butyl-benzene is lower by a factor of 100 than that in the CH3 group of toluene. For comparison, the second line shows the relative rate constants determined by Streitwieser and Van Sickle (1962a) for catalysis by a 0-06n solution of lithium cyclohexylamide in cyclohexylamine (49-9°). 

The biradical corresponding to 16a produces indanol 18 quantitatively, whereas the biradical from 16b undergoes disproportionation to form mainly 19. The quantum efficiency for the formation of 18 was 0.03 in hydrocarbon solvent, and 1.0 in methanol. In contrast, the total quantum yield for 16b was rather low (0.02-0.05) in both hydrocarbon and methanol solvents. These differences were ascribed to a considerably smaller dihedral angle between the carbonyl and t-butyl benzene in the triplet excited state of 16a in comparison to 16b, and a differing rotational freedom in the biradical 17 intermediate species. 

To a solution of 4,6-dichloro-5-(o-methoxyphenoxy)-2-(4-pyridyl)-pyrimidine (6g) dissolved in 100 ml THF was added 4-t-butyl benzene sulfonamide potassium salt at ambient temperature and the mixture stirred overnight. The reaction mixture was then poured into 150 ml of water and diethyl ether and the pH adjusted to 5 by the addition of HO Ac. Thereupon a precipitate formed and the product isolated by filtration as a beige crystal. MS data supplied. 

Zirconium monochloride mono(0-2,4-di-t-butyl)benzene 2THF (1)... 

CtS stationaiy phase. The mobile phase was a mixtune of mcrhanol and water (25Hi a flow rate of 2 ml/inln. The solutes, were 1, benzEJic 2, toluene 3, ediyJ benzene 4, i sopJ opy] benzene 5, t-butyl benzene 6, aiitliraeenc and 1, Rodium eJiloitde. 

Mononitration of benzene is carried out at about 60° and dinitration meta isomer) at about 95° further nitration is difficult. In a similar manner, toluene gives rise to o- and p-nitrotoluenes (90%) and a small quantity of the meta isomer, isopropylbenzene (cumene) goes predominantly to p-nitrocumene (89%), and t-butylbenzene to p-nitro-t-butyl-benzene (74%). For the nitration of an easily oxidizable substance like p-cymene, a good emulsion and careful temperature control are important. ... 

Regiocontrol in the insertion sequence appears to be steric in origin, with laige groups directed away from the bulky metal. A tail-to-tail linkage sequence followed by rearrangement leads to l,3,S-tris(t-butyl)benzene as the sole benzenoid product from trimerization of r-butylacetylene in the presence of PdCb. 

Why is the 1,4 isomer, 1,4-di-r-butyl-2,5-dimethoxybenzene, the major product in the alkylation of dimethoxybenzene Would you expect either of the following compounds to be formed as side products 1,3-di-t-butyl-2,5-dimethoxybenzene 1,4-dimethoxy-2,3-di-t-butyl-benzene Why or why not ... 

Attempted Friedel-Crafts acylation of benzene with t-BuCOCI gives some of the expected ketone, as a minor product, and also some t-butyl benzene, but the major product is the disubstituted compound C. Explain how these compounds are formed and suggest the order in which the two substituents are added to form compound C. 

We have now answered the question but you might like to go a stage further. Both A and C ire formed with alkylation of benzene as the first step. The decomposition of the acylium ion is evidently faster than the acylation of benzene. However, when B reacts further, it is mainly icylated (only a small amount of di-t-butyl benzene is formed). Evidently, the decomposition of ne acylium ion is slower than the acylation of B This is not, in fact, unreasonable as the t-Bu roup in B accelerates electrophilic attack - it is just a dramatic demonstration of that acceleration. 

Methyl-3-t-butyl-benzene 11 Arom2 0.03-0.11 Gasoline LUFT 1988... 

Benzene Toluene Ethyl- benzene 1-Propyl-benzene t -Butyl benzene... 

The sodium hydroxide solution to be concentrated and a hydrocarbon (e.g., ethyl benzene or t-butyl benzene) are pumped to a pressure of 2,000 psig and passed to a static mixer kept at 330 °C. From the mixer the stream is conveyed to a phase separator kept at 335 °C, where the heavier sodium hydroxide phase settles to the bottom. The hydrocarbon-water phase is withdrawn from the top of the separator, is cooled in a heat exchanger, and is depressurized to ambient across a valve. The hydrocarbon and liquid water separate and are withdrawn separately. The formation of distinct water and hydrocarbon phases actually cKCurs during the cooling step in heat exchanger. 

Beilstein Handbook Reference) Aceto-phenone, 4 -t-butyl-2, 6 -dimethyl-3, 5 -dinitro- 2-Acetyl-5-l-butyl-4,6-clinitroxylene AI3-02440 BRN 2062638 4-t-Butyl-3,5-dinitro-2,6-dimethylaceto-phenone 4 -t-Butyl-2, 6 -dimethyl-3, 5 -dinitroaceto-phenone CCRIS 4677 1-(4-(1,1-Dimethylethyl)-2,6-dimethyl-i5-dinitrophenyl)-ethanone 2,6-Dinitro-3,5-di-methyl-4-acetyl-t-butyl-benzene 3, Dinitro-2,6-di-methyl-4-t-butylacetophen-one EINECS 201-328-9 Ethanone, 1-(4-(1,1-dimethyl-ethyl)-2,6-dimethyl-3,5-Musk ketone NSC 15339 Acetophenone, 4 -t-butyl-2, 6 -dimethyl-3, 5 -dinitro- 1-Acetyl-4-t-butyl-2,6-dimethyl-3,5-dinitro-benzene 4-t-Butyl-2,6-dimethyi-3,5-dinitro-acetophen-one 4 -t-Butyl-2, 6 -dimethyl-3, 5 -dinitro-acetophenone 1-[4-(1,1-Dimethylethyl)-2,6-dimethyl-3,5-dinitrophenyl]-ethanone. An artificial musk perfume. Solid mp = 138-140°. AM Aromatics Pvt, Ltd. Zhejiartg Winsun Imp. And Exp. Co., Ltd. 

Benzene, (2-chloro-1,1-dimethylethyl)- (p-Chloro-a,a-dimethyl)ethylbenzene (p-Chloro-t-butyl)benzene (2-Chloro-1,1-dimethylethyl)benzene p,p-Dimethylphen-ethyl chloride EINECS 208-197-7 2-Methyl-2-phenyl-propyl chloride Neophyl chloride NSC 54159. Liquid bp = 223 , bpi8 = 105" very soluble in EtOH, EtzO, MezCO, CeHe. 

FIGURE 47 The structure of bis(7j -l,3,S-tris(t-butyl)benzene)gadolinium(0) and bis ( 7 -2,4,6-tris(t-butyl)phosphinine)holmium(0), obtained by co-condensation of metal vapours with the ligands. Figure was redrawn after Arnold et al. (1997) and Brennan et al. (1987). 

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