Alkylation with isoamylene

The cmde product formed from the alkylation of phenol with isoamylene contains principally 2-/ r2 -amylphenol, 4-/ r2 -amylphenol, and 2,4-di-/ r2 -amylphenol. 4-/ r2 Amylphenol is purified to its typical assay of 99+% by fractional distillation. 4-/ r2 -Amylphenol [80-46-6] is commercially available as a soHd, flaked material packaged ia paper or plastic bags (25 kg net weight) or as a molten material ia tank wagon or railcar quantities. 

Diall lated Phenols. 2,4-Di-tert-amjlphenol (2,4-DTAP) or 2,4-bis(l,l-dimethylpropyl)phenol is produced by the alkylation of phenol with isoamylene under acid catalysis in a mole ratio of 2 1 (isoamylene to phenol). The cmde alkylation product contains 4-/ f2 -amylphenol,... 

Supplemental processes which can be operated in conjunction with alkylation and/or sulfuric acid production can influence the overall economics. Examples are (1) the integration of normal butane-to-isobutane isomerization with alkylation, utilizing common fractionation equipment and (2), utilizing 65% sulfuric acid extraction of isobutylene or isoamylene from olefins fed to alkylation, justified by monetary return on sale of the high purity iso-olefin as a petrochemical feedstock, which reduces quantity of alkylate produced and reduces isobutane required while producing still higher quality alkylate with sulfuric acid catalyst. 

Direct evidence of this hydrogen transfer reaction in the presence of sulfuric acid was obtained in an investigation (Marschner and Carmody, 24) of the alkylation of isobutane with isoamylene (as i-amyl alcohol) and of... 

Methyl salicylate has been alkylated with isobutylene and isoamylene on Indion 130, a macroporous sulfonated styrene-divinylbenzene resin with cross-... 

If the hydroboration reaction is to be used to convert 1-alkynes into aldehydes, some way to stop the addition at the vinylborane stage is needed. The problem is that there is not enough steric hindrance at the end carbon of the vinylborane. The solution is to build extra steric hindrance into the other alkyl groups attached to the boron of the vinylborane. A borane, R2BH, with two bulky R groups already attached to the boron is used as the hydroboration reagent. One such reagent is prepared by the reaction of two equivalents of 2-methyl-2-butene (also known by the common name of isoamylene) with borane to produce a dialkylborane called di si amyl borane (a shortened version of diisoamylborane) ... 

Once there are two of the bulky alkyl groups attached to the boron, it is difficult to add a third group. Disiantylborane is not reactive enough to add to isoamylene, a trisubstituted alkene, because of these steric effects. However, it is reactive enough to add to a 1-alkyne to produce a vinylborane, but it is too sterically hindered to react with the... 

Three processes are associated with production of olefins. One process is designed to convert natural gas or raw methanol to ethylene, propylene, and butane. The second process is designed to produce isobutylene and isoamylene feedstocks from hydrocarbon feedstock. This material is used in production of ethers, polymerization, and linear olefins for alkylation. The third process selectively converts gas oil feedstocks into high-octane gasoline and distillate, and C2-C5 olefins. 

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