Alkylation biphenyl with propylene

Short-chain alkylated biphenyls are the principal biphenyl derivatives in commercial use. They are generally produced by Hquid-phase Friedel-Crafts alkylation of biphenyl with ethylene, propylene, or mixed butenes. A series of mixed ethylated biphenyl heat-transfer fluids (trademarked Therm S-600, 700, 800) is marketed by Nippon Steel. A mixed diethylbenzene—ethylbiphenyl heat-transfer fluid is also available from Dow (63). Monoisopropylbiphenyl [25640-78-2] largely as a mixture of meta- and para-isomers is produced by Koch Chemical Co. Monoisopropylbiphenyl (MIPB) was selected by Westinghouse (64,65) as a PCB replacement in capacitors and this is its primary appHcation today. For a time MIPB was also employed as a PCB replacement in pressure sensitive copy paper, but this outlet has since given way to other dye solvents. A similar product consisting of a mixture of j -butylbiphenyl isomers [38784-93-9] (66) is currently the favored dye solvent for pressure sensitive copy paper (67) manufactured in the United States. 

Short-chain alkylated biphenyls are the principal biphenyl derivatives in commercial use. They are generally produced by liquid-phase Friedel-Crafts alkylation of biphenyl with ethylene, propylene, or mixed butenes. 

Table 1. Alkylation of biphenyl (BP) with propylene at 523 K. Analysis after 20 h in batch experiments using 500 g BP and 10 g catalyst at 8.43 kg cm propylene pressure. Stimng rate 2000 rpm (Reprinted with permission from Baltzer Science Publishers).

Effect of the Dealumination of H-Mordenite - The catalytic activities of the isopropylation of naphthalene are not proportional to the acid density and are not enhanced by the dealumination, as is the case of the isopropylation of biphenyl.Figure 9 shows the yields of products and the distributions of 2-IPN and DIPN isomers at 80% conversion in the alkylation of naphthalene over HM with Si02/Al203 ratio from 10 to 220 at 250 °C under constant propylene pressure of 0.8 MPa. The catalytic features of HM with low and high ratios were also quite different. Significant changes in the selectivities for... 

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