Carbon tetrabromide → Triphenylphosphine Oxide

Participants

Reaction Steps

To a stirred suspension of 6.5 g of zinc dust in 300 ml of methylene chloride was added, successively, 26.2 g of triphenylphosphine and 33.2 g of carbon tetrabromide. A mildly exothermic reaction carried the temperature of the mixture to 35°-40°, no cooling being applied. The mixture then was stirred for one hour at room temperature, then cooled to 15° and treated with 10.7 g of 5-nitro-2-furaldehyde. The mixture then was stirred overnight at 25° and filtered to remove suspended salt. The filtrate was concentrated under reduced pressure and the residue was extracted with two 200 ml portions of ether. The combined ether extracts were concentrated to a volume of about 100 ml, diluted with an equal volume of pentane, and cooled. Filtration gave triphenylphosphine oxide. The filtrate was concentrated under reduced pressure and the residue was recrystallized from either/pentane (1:2) to give a solid, m.p.: 73°-78°. Recrystallization of the solid from either/pentane (1:4) gave 2 as yellow prisms, m.p.: 76°-78°.

Provenance & Evidence