76783-54-5

Upstream product

• 92-52-4 biphenyl 
• 115-11-7 isobutene 
• 253185-03-4 tert-butylbenzene 
• 769-92-6 4-tert-Butylaniline 

Relevant academic research and scientific papers

The alkylation of biphenyl over one-dimensional twelve-membered ring zeolites. the influence of zeolite structure and alkylating agent on the selectivity for 4,4'-dialkylbiphenyl

Alkylation, i.e., isopropylation, s-butylation, and t-butylation, of biphenyl (BP) was examined over one-dimensional twelve-membered (12-MR) zeolites: Mordenite (MOR) and SSZ-24 (AFI) with straight channels, and SSZ-55 (ATS) and SSZ-42 (IFR) with corrugated channels. Types of zeolites and alkylating agents highly influenced the selectivities for dialkylbiphenyl (DABP) isomers. Shape-selective formation of 4,4'-diisopropylbiphenyl (4,4'-DIPB) was observed over MOR and AFI; however, ATS and IFR gave 4,4'-DIPB only in low selectivities at 250°C: 87% over MOR, 60% over AFI, 20% over ATS, and 30% over IFR. The selectivities for 4,4'-di-s-butylbiphenyl (4,4'-DSBB) in the,s-butyl-ation were higher than those for 4,4'-DIPB: 95% over MOR, 85% over AFI, 75% over ATS, and 50% over IFR. The t-butylation afforded selectively 4,4'-di-t-butylbiphenyl (4,4'-DTBB) over the zeolites: 96-97% over MOR and AFI, 90% over ATS, and 80% over IFR. These results in the alkylation indicate the exclusion of 4,4'-DABP from other bulky DABP isomers by steric restriction in zeolite channels is an important key for the high shape-selectivity. Even zeolites with large channels, such as ATS and IFR, can have shape-selective nature if the bulky moieties, such as,s-butyl and t- butyl groups, are large enough to differentiate the transition state of the least bulky 4,4'-DABP from those of the other isomers inside their channels. The selectivity for 4,4'-DABP decreased at high temperatures in some alkylations: isopropylation over MOR, and s-butylation and t-butylation over MOR, AFI, and ATS. The decreases are due to the iso-merization of 4,4'-DABP at external acid sites, because the channels are not large enough for the isomerization of 4,4'-DABP to bulkier 3,4'-DABP. However, the isopropylation over AFI was accompanied by the isomerization of 4,4'-DIPB at external and internal acid sites, because the channels are large enough for the isomerization of 4,4'-DIPB.

tert-Butylation of Biphenyl; Determination of the Structure of Reaction Products by Means of Independent Syntheses

The Friedel-Crafts alkylation of biphenyl with tert-butyl chloride in carbon disulfide using aluminium trichloride as catalyst leads to the formation of only 9 of the 209 theoretically possible tert-butylbiphenyls, namely 3- and 4-tert-butylbiphenyl, 3,5-, 3,3'-, 3,4'-, and 4,4'-di-tert-butyl-biphenyl, 3,3',5-, and 3,4',5-tri-tert-butylbiphenyl as well as 3,3',5,5'-tetra-tert-butylbiphenyl.These have been separated by gas chromatography and identified by means of independently synthesized compounds in combination with GC-MS determinations.Five of these compounds have been prepared for the first time.