Trimethyl phosphite → Dimethyl 1-eicosanyloxycarbonylphosphonate

Participants

Reaction Steps

1-Eicosanyl chloroformate (6.0 g, 16.6 mmol) was added slowly to refluxing P(OMe)3 30 (mL), and after 2 hours the mixture was left at room temperature overnight. Excess P(OMe)3 was removed by vacuum distillation, and the remaining white solid was collected, washed with cold hexane, and recrystallized from hexane to obtain colorless crystals from which traces of hexane were not fully removed (7.0 g, 97% yield); mp 53-54° C.; TLC: Rf 0.39 (silica gel, 98:2 CHCl3—MeOH); IR (KBr): υ 2950, 2915, 1705, 1540, 1280, 1220 cm−1; 1H NMR (CDCl3) δ0.8-1.8 (m, >39H, CH3(CH2)18), 3.9 (d, 6H, P(OCH3)2), 4.3 (t, 2H, CH2O). Anal. Calcd. for C23H47O5P.0.15C6H14: C, 64.13, H, 11.08; P, 6.92. Found: C, 63.91; H, 10.91; P, 6.62.

Provenance & Evidence