4-Bromoanisole → Bis(4-methoxyphenyl)-2,4,5-trimethylphenylphosphine oxide

Participants

Reaction Steps

A reaction flask under nitrogen containing magnesium turnings (120 g, 4.94 mol) and 412 mL THF was charged with 0.5 g of 1,2-dibromoethane and heated to reflux for 1 h. A separate flask was charged with 5-bromo-1,2,4-trimethylbenzene (300 g, 1.51 mol), dissolved in 568 mL of THF. The heat was removed from the first flask and the 5-bromo-1,2,4-trimethylbenzene solution was added dropwise at a rate to maintain reflux. 4-Bromoanisole (536.7 g, 3.01 mol) was then added over 1.5 h at 75° C. reaction temperature. After holding the reaction mixture overnight, POCl3 (231 g, 1.51 mol) was added dropwise at 40-80° C. The product mixture was isolated by aqueous workup to give 453.6 g (79% yield) of product mixture as a viscous liquid. The structure was consistent with NMR data.

Provenance & Evidence