4-Isopropylphenol, reaction with

Preparation of Bis-1, 4-(disubstituted)perfluorobenzene and Bis-4,4 (disubstituted)perfluorobiphenyl. To a solution of 4.85 mmole of HFB or PFB and 9.65 mmole of 4-isopropylphenol or 4- -butylthiophenol in 20 ml of solvent was added 20.8 mmole of K2CO3 and 1.34 mmole of 18-crown-6 ether. The magnetically stirred heterogeneous mixture was heated to reflux or to 80 with DMAc and maintained under dry N2 for 4-24 hr. For reactions with... 

The fate of peroxy radicals at sediment or soil surfaces has been considered by Pohlman and Mill (1983). They examined the ability of common soil constituents to quench the reaction of an alkylperoxy radical with a reactive probe molecule, p-isopropylphenol. They found that reactions with organic matter were dominant over possible reactions with the mineral constituents, except for possibly Cu but natural humic materials appeared to be a rather poor scavenger, presumably because the bulk of their structure consisted of unreactive moieties such as polysaccharides and aliphatic chains. They also concluded that phenols and other reactive xenobiotics might be partially susceptible to removal through reaction with these radicals. 

The key stage is the alkylation of cumene. From its reaction in the liquid phase at 300°C in the presence of a silica/alumina catalyst with 3 moles of propene the 1,4-isomer required for hydroquinone is separated by fractionation (ref.30) and the mixture of 1,2- and 1,3-di-isopropylbenzenes together with the tri-isopropyl isomer equilibrated with benzene at 270°C with the same catalyst to enrich the proportion of the 1,3-compound required for the synthesis of resorcinol. The sequence of steps for hydroquinone is shown. By-product 4-isopropylphenol is mostly reoxidised and recycled giving a total yield of 71% based on di-isopropylbenzene (ref.31). 

Next to phenol the herbicide isoproturon is one of the few cumene derivatives with any large-scale importance. Nitration of cumene yields 2-/4-nitrocumene in the ratio 35 65. The 4-isomer is recovered by vacuum distillation and is then reduced to cumidine (4-isopropylaniline). (Cumidine can also be produced by ammonolysis of 4-isopropylphenol, which arises as a by-product during the oxidation of 1,4-diisopropylbenzene to produce hydroquinone). Cumidine is reacted with phosgene to give 4-isopropylphenyl isocyanate. Reaction of 4-isopropyl-phenyl isocyanate with dimethylamine yields isoproturon, which in Western Europe is produced in quantities of around 6,000 tpa. 

The reactions of phenol with isopropyl alcohol and -propyl alcohol occurred slowly, and the major products with isopropyl alcohol are 2-isopropylphenol and 2,6-diisopropylphenol. The mole fraction yield as a function of time is shown in Fig. 9.46. 

These results may be contrasted to the reaction of phenol with tert-butyl alcohol where the second tert-butyl group went to the 4-position of the phenol, probably due to steric effects. In the case of isopropyl alcohol, steric effects are less severe and the second isopropyl group went to the 6-position. Reaction of phenol with 1-propanol proceeded even more slowly than the isopropyl alcohol. The yield of products was less than 5% yield over a time period of 144 h, with the major product 2-isopropylphenol plus very small amounts of 2,6-diisopropylphenol and 2-n-propylphenol. Clearly, the incipient primary carbonium ion rearranged to the more stable secondary carbonium ion. 

Figure 9.46 Mole fraction product yields as a function of time for the reaction of phenol with isopropyl alcohol in water at 275° C. phenol. 2-isopropylphenol. A 2,6-diisopropylphenol. ...

Preparation by reaction of acetic anhydride on 3-methyl-4-isopropylphenol (p-thymol) with 70% perchloric acid at 125-135° (32%) [2306],... 

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