Exxonmobil Chemical Patents Inc.

Aaron B Pavlish

Neeraj Sangar

Michael Salciccioli

Ali A Kheir

Tan-Jen Chen

Jihad Mohammed Dakka

Gary David Mohr

Lorenzo C DeCaul

Emiel De Smit

Gregory J De Martin

Processes for selectively alkylating and/or dealkylating one ring of cyclohexylbenzyl and/or biphenyl compounds are provided. Such selective alkylation and/or dealkylation takes place through a transalkylation reaction between the cyclohexylbenzyl compound and a substituted or unsubstituted benzene, which replaces the phenyl moiety of the cyclohexylbenzyl compound. The transalkylated cyclohexylbenzyl may be dehydrogenated to give a corresponding biphenyl compound. The same reaction steps can be utilized with respect to biphenyl compounds by first partially hydrogenating one phenyl ring of the biphenyl compound, thereby obtaining a corresponding cyclohexylbenzyl compound, which may undergo the transalkylation and, optionally, subsequent dehydrogenation. Combinations of any two or more of partial hydrogenation, transalkylation, and dehydrogenation enable targeted substitution (or de-substitution) of only one ring of cyclohexylbenzyl and/or biphenyl compounds, thereby providing superior control in designing the synthesis of these compounds.

Transalkylated cyclohexylbenzyl and biphenyl compounds

In a process for producing dialkylbiphenyl compounds, a feed comprising substituted cyclohexylbenzene isomers having the formula (I): wherein each of Rand Ris an alkyl group and wherein the feed comprises m % by weight of isomers in which Ris in the 2-position, based on the total weight of substituted cyclohexylbenzene isomers in the feed; is transalkylated with a compound of formula (II): to produce a transalkylation product comprising substituted cyclohexylbenzene isomers having the formula (I) and including n % by weight of isomers in which Ris in the 2-position, based on the total weight of substituted cyclohexylbenzene isomers in the transalkylation product, wherein n&#x3c;m. At least part of the transalkylation product is then dehydrogenated under conditions effective to convert at least part of the substituted cyclohexylbenzene isomers in the transalkylation product to dialkylbiphenyl compounds.

Process for preparing dialkylbiphenyl isomer mixtures

In a process for dehydrogenating cyclohexylbenzene and/or alkyl-substituted cyclohexylbenzene compounds, a dehydrogenation catalyst comprising at least one Group 10 metal compound on a support is heated in the presence of hydrogen from a first temperature from 0&#xb0; C. to 200&#xb0; C. to a second, higher temperature from 60&#xb0; C. to 500&#xb0; C. at a ramp rate no more than 100&#xb0; C./hour. The dehydrogenation catalyst is contacted with hydrogen at the second temperature for a time from 3 to 300 hours to produce an activated dehydrogenation catalyst. A feed comprising cyclohexylbenzene and/or an alkyl-substituted cyclohexylbenzene compound is then contacted with hydrogen in the presence of the activated dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising biphenyl and/or an alkyl-substituted biphenyl compound.

Activation of dehydrogenation catalysts

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Humble, TX, United States of America

Aaron B Pavlish