Triphenylphosphine → 4-Carboxyphenethyltriphenylphosphonium bromide

Participants

Reaction Steps

p-Bromoethylbenzoic acid (15 mmol, 3.45 g) and triphenylphosphine (16.5 mmol, 4.32 g) were refluxed in 100 ml m-xylene for 9 h (oil bath temperature 150° C.). The mixture was then cooled down, the solid formed was filtered, washed with m-xylene (2×20 ml), hexanes (2×20 ml), and air-dried to give 6.05 g (82%) of beige crystals. Recrystallization from MeOH—CHCl3-hexanes (˜1:3:5) afforded 2.8 g (38%) of pure off-white crystals of 4-carboxyphenethyl(triphenyl)phosphonium bromide. 1H NMR (400 MHz, CDCl3) δ 7.74 (d, 2H, 8.4 Hz, H2, H6 Ar), 7.68 (m, 3H, Ph3P), 7.55 (m, 12H, Ph3P), 7.09 (d, 2H, 8.4 Hz, H3, H5 Ar), 3.48 (m, 2H, CH2—P), 2.86 (m, 2H, CH2—Ar)

Provenance & Evidence