K inetically dimeriza tion of Į- methylstyr en by H۶ P۲W۱۸O۶۲ catalyst: Te mperatur e and time aspects

The dimerization of aryl alke nes is atom -economica l reaction that gives access to useful intermediates. Considerable attention has been focused on the transformations because o f the demand for the form ation of im portant inte rmediates in the fields of material engineerin g and pharmac euticals. Acid-catalyzed dimerization of Į-methylstyrene (۱) can lead to ۲,۴-diphe nyl-۴-methyl-۱-pentene (۲), ۲,۴-diphenyl-۴-methyl-۲-pentene (۳) and ۱,۱,۳-trimethyl-۳- phenylindan (۴) whic h are industrially relevant in several co ntexts. The unsaturated dimers of Į-methystyre ne, particularly ۲ are industrially important and are useful as chain-transfer agents or molecular weight regulators in the production of polymers such as polystyrene, AS resin, AB S resin, SB R, and the like, furthermore derivativ es of ۴ are utilized in the electroni c industry, in the produ ction of pol ymers and as flame retardants. In this work, we report the effect of different reaction time s and temperatures on prod ucing dimer s in the pre sent of catalytic amount of the Daw son (H۶P۲W۱۸O۶۲) heteropolyacid (HPA -D) [۱-۳].

کلیدواژه ها:

Heteropolyacids ، Ca talysis ، Dim erization ، Į-Methylstyrene