Fert-butylbenzene

Some degree of regioselectivity can be imposed on l//-azepine formation if the arene has substituents of high steric demand.63 For example, the thermolysis of ethyl azidoformate in a tenfold molar excess of 1,4-di-fert-butylbenzene yields a 95 5 mixture of the di-zerr-butyl-l//-azcpincs 3 and 4, crystallization of which yields the pure 3,6-di-/er/-butyl isomer 3. 

Pheny 1-3-pheny 1 imino-3-// -indole N -oxide (an indolic nitrone) reacts with triethyl and triisopropyl phosphite in refluxing xylene and fert-butylbenzene to give 2-phenylimino-3// -indole (indolenine) in very good yield (505). 

Fig. 6.15. El spectrum of fert-butylbenzene. Again, molecular ion and primary fragment ion are dominating the spectmm. Spectrum used by permission of NIST. NIST 2002.

BuAc, see sec-Butyl acetate sec-BuAc, see sec-Butyl acetate f-BuAc, see fert-Butyl acetate i-BuBz, see Isobutylbenzene n-BuBz, see Butylbenzene sec-BuBz, see sec-Butylbenzene f-BuBz, see fert-Butylbenzene fert-BuBz, see fert-Butylbenzene BUGS, see 2-Butoxyethanol Bug master, see Carbaryl Bunt-cure, see Hexachlorobenzene Bunt-no-more, see Hexachlorobenzene 1-BuOH, see 1-Butanol... 

Pseudobutylbenzene, see fert-Butylbenzene Pseudocumene, see 1,2,4-Trimethylbenzene Pseudocumol, see 1,2,4-Trimethylbenzene Puralin, see Thiram PX 104, see Di-n-butyl phthalate PX 138, see Di-n-octyl phthalate Pyranton, see Diacetone alcohol Pyranton A, see Diacetone alcohol p-Pyrene, see Pyrene... 

The apparent order of Vp with respect to hydrocarbon depends somewhat on the solvent, as shown in Figure 1. In fert-butylbenzene, which is inert chemically and clearly resembles the xylenes, Vp is first order in hydrocarbon, but deviations occur in o-dichlorobenzene. This principle affects generally the choice of solvents (21). Thus, even in radical oxidation, where solvent effects are much weaker than in ionic reactions, proper choice of solvent is essential if kinetic laws are to be observed over a wide range of reagent concentrations. 

Figure 3.4. 6-Cascade benzene[3-l,3,5] (5-(3S,4S-l,6-dioxa-3,4-0-isopropylidene-3,4-dihydroxyhexyl)-l,3-phenyl-ene) -(SS S-l.b-dioxa-S -O-isopropylidene-S -dihydroxyhexyO-fert-butylbenzene.

The carbocation electrophile in a Friedel-Crafts reaction can be generated in ways other than by reaction of an alkyl chloride with AICI3. For example, reaction of benzene with 2-methylpiopenc in the presence of H,P04 yields fert-butylbenzene. Propose a mechanism for this reaction. 

Most prismanes were synthesized by photoreaction of benzenes. The formed intermediates were supposed to be Dewar benzenes which were cyclized by a (2- addition reaction. An early example is the photolysis of tri-fert-butylbenzene as mentioned before. In this case, a mixture of the prismanes was isolated. 

Figure 12.5 illustrates attack on the benzene ring by ferf-butyl cation (step 1) and subsequent formation of fert-butylbenzene by loss of a proton from the cyclohexadienyl cation intermediate (step 2). 

Step 2 Loss of a proton from the cyclohexadienyl cation intermediate yields fert-butylbenzene. 

The more efficient the alkyl group is at releasing electrons, the greater is the stabilization of the intermediate carbocation and the rate of electrophilic attack. Thus, fert-butylbenzene is nitrated faster than toluene. 

The sum of these partial rate factors is 147 for toluene, 90 for tert-butylbenzene. Toluene is 147/90, or 1.7, times more reactive than fert-butylbenzene. 

Togo and coworkers have found that alkyl aryl ketones and dialkyl ketones could be converted into the corresponding a-tosyloxyketones in generally low yields by the reaction with mCPBA and p-toluenesulfonic acid monohydrate in the presence of a catalytic amount of molecular iodine in a mixture of acetonitrile and 2,2,2-trifluoroethanol (method A, Scheme 4.5) [23]. The same conversion of ketones into the corresponding a-tosyloxyketones could be smoothly carried out by the reaction with mCPBA and TSOH H2O in the presence of catalytic amounts of iodine and fert-butylbenzene in a mixture of acetonitrile and 2,2,2-trifluoroethanol (method B). In these reactions, p-iodotoluene 8 (method A) and 4-fcrr-butyl-l-iodobenzene 9 (method B) are formed at first and are then converted into the corresponding [hydroxy(tosyloxy)iodo]arenes, ArI(OH)OTs,... 

C8H3O2 o-Toluic acid 84.3 C10H14 fert-Butylbenzene 101.8... 

From these observations, we conclude that if a benzylic hydrogen exists, then the benzylic carbon is oxidized to a carboxyl group and all other carbons of the side chain are removed as CO2. If no benzylic hydrogen exists, as in the case of fert-butylbenzene, no oxidation of the side chain occurs. 

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