Acetic Acid → p,p'-(Phenylphosphinylidene)bisphenol

Participants

Reaction Steps

A mixture of bis(4-methoxyphenyl)phenyl phosphine oxide (59.83 g, 0.1768 mol), 48% hydrobromic acid (400 ml, 3.536 mol), and glacial acetic acid (215 ml) was refluxed for 24 hrs. As the solution cooled to room temperature, the crude product remained in solution. The hydrobromic acid/glacial acetic acid mixture was added to stirred distilled water at room temperature to afford a light pink solid. The crude solid was washed several times in water and dried at ˜105° C. to afford 46.4 g (˜85% yield). The solid was dissolved in ethanol, treated with activated charcoal, and filtered through Celite 545. Distilled water was added to the stirred warm solution until a 50% aqueous ethanol solution was obtained. The mixture was then allowed to cool to ambient temperature. The product was recovered by filtration and dried under vacuum at 50° C. This recrystallization procedure was repeated an additional time to afford 22.66 g (41% yield) of a white solid, DSC (heating rate of 10° C./min) exotherm at 157° C. with sharp peaks at 227 and 233° C. [literature 233-234° C. (A. E. Senear, W. Valent, and J. Wirth J. Org. Chem. 25, 2001, 1960.)]

Provenance & Evidence