M-Di bromobenzene

TRINITROBENZENE m-DIBROMOBENZENE m-CHLORONITROBENZENE o-CHLORONITROBENZENE p-CHLORONITROBENZENE tn-D I CHLOROBENZENE o-DICHLOROBENZENE p-DI CHLOROBENZENE m-DIFLUOROBENZENE o-DIFLUOROBENZENE p-DIFLUOROBENZENE m-DI NITROBENZENE o-DINITROBENZENE p-DINITROBENZENE BROMOBENZENE MONOCHLOROBENZENE m-CHLOROPHENOL o-CHLOROPHENOL p-CHLOROPHENOL... 

You have three bottles containing the three isomeric di-bromobenzenes they have the melting points +87 , +6 , and - 7 . By a great deal of work, you prepare six dibromo-nitrobenzenes (CeHsBraNOa) and find that, of the six, one is related to (derived from or convertible into) the di-bromobenzene of m.p. +87 , two to the isomer of m.p. +6 , and three to the isomer of m.p. -7 . 

The choice of an ionic liquid was shown to be critical in experiments with [NBuJBr (TBAB, m.p. 110°C) as a catalyst carrier to isolate a cyclometallated complex homogeneous catalyst, tra .s-di(ri-acetato)-bis[o-(di-o-tolylphosphino) benzyl] dipalladium (II) (Scheme 26), which was used for the Heck reaction of styrene with aryl bromides and electron-deficient aryl chlorides. The [NBu4]Br displayed excellent stability for the reaction. The recycling of 1 mol% of palladium in [NBu4]Br after the reaction of bromobenzene with styrene was achieved by distillation of the reactants and products from the solvent and catalyst in vacuo. Sodium bromide, a stoichiometric salt byproduct, was left in the solvent-catalyst system. High catalytic activity was maintained even after the formation of visible palladium black after a fourth run and after the catalyst phase had turned more viscous after the sixth run. The decomposition of the catalyst and the formation of palladium... 

---