Benzene, 1-(chloromethyl)-2,3,4,5,6-pentamethyl- → 1,2,3,4,5-Pentamethylcyclopentadiene

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Reaction Conditions

Reaction Steps

A 250 ml roundbottom flask equipped with a condenser, stirrer, thermometer and dropping funnel with nitrogen inlet was charged with 100 ml THF in which pentamethylbenzyl chloride (19.8 g, 0.10 mol) was dissolved. The solution was cooled to -20° C. and sodium cyclopentadienyl (60 ml, 2.0 M in THF) was added; the solution was stirred for 48 hours at 22° C. GC analysis showed 90% conversion to pentamethylcyclopentadienyl. A precipitate was filtered off and the solvent was evaporated. The remaining residue was recrystallized from hot dichloromethane/petroleum ether. After recrystallization, pentamethylcyclopentadiene (16 g) was obtained. The product was characterized by GC, GC-MS, 13C and 1H NMR.

Provenance & Evidence