Hydrogen Bromide → Phosphine, triphenyl-, hydrobromide

Participants

Reaction Steps

A solution of 26.23 g (0.10 mole) triphenylphosphine in 100 ml toluene at 0°-5° C. was perfused with HBr gas for 20 minutes, 250 ml ethyl ether was added and the mixture stirred for 20 minutes. The mixture was filtered, the white solid cake slurried in ether (500 ml), filtered again and air-dried to obtain 33.2 g (97%) of triphenylphosphonium bromide, m.p. 203°-205° C. (decomp.). In a separate flask 33 g (0.096 mole) of this salt, 11.9 g (0.096 mole) o-hydroxybenzyl alcohol and 100 ml dry acetonitrile were combined and heated at reflux for two hours. The resulting solution was cooled, filtered, the cake washed with 100 ml acetonitrile and dried in vacuo at 120° C. to obtain 26.2 g (61%) of the desired product, m.p. 223°-225° C. Mass spectrum (m/e): 368, 291, 262, 107.

Provenance & Evidence