Triethyl phosphite → Diethyl 2-(2-Bromoethyl)benzylphosphonate

Participants

Reaction Steps

In a round bottom flask equipped for distillation, 15.0 g (54 mmol) of 2-(2-bromoethyl)benzyl bromide and 9.0 g (54 mmol) of triethylphosphite were heated on an oil bath with stirring at 90°-100° C. When ethyl bromide ceased distilling off (1 h) the remaining volatile by-products and triethylphosphite were removed from the mixture by distillation under vacuum. The viscous oil which remained was chromatographed on a column of silica gel with hexane-ethyl acetate (1:1) as eluant. The combined fractions were concentrated under reduced pressure to yield 12.5 g (70%) of the product as a yellow oil. IR(neat): 2987, 1249, 1170, 1064, 964, 802 cm-1. 1H NMR(CDCl3) δ 1.2 (t, 6H); 3.0-4.35 (m, 10H); 7.2 (s, 4H).

Provenance & Evidence