Triphenylphosphine → Triphenylphosphine Oxide

Participants

Reaction Steps

To a solution of 1-azido-2-(6-bromo-3-fluoro-pyridin-2-yl)-propan-2-ol (11.2 g, 40.7 mmol) in THF (60 ml) was added triphenylphosphine (10.68 g, 40.7 mmol) and the reaction mixture was stirred for 18 hours at room temperature. The solvent was removed in vacuo and the residue obtained was dissolved in diethylether and filtered through a cotton plug to remove triphenylphosphine oxide. The filtrate was washed with citric acid (9.6 g in 20 ml of water) and the organic phase was separated. The aqueous layer was made basic with 2N NaOH and extracted with diethylether. The organic layer was dried over sodium sulfate, filtered and evaporated to yield the title compound with some TPPO present: 8.1 g yellow oil (69% yield). TLC (cyclohexane/ethyl acetate 2:1) Rf=0.28; LCMS RtH6=0.46 (ES+ 231, 233); 1H-NMR (400 MHz, CDCl3): 7.34 (dd, 1H), 7.24 (dd, 1H), 1.99 (s, 1H), 1.89 (s, 1H), 1.65 (s, 3H, CH3).

Provenance & Evidence