Triphenylphosphine → Triphenylphosphine Oxide

Participants

Reaction Steps

A mixture of methanesulfonic acid 2-azido-1-(2-bromo-5-fluoro-pyridin-4-yl)-1-methyl-ethyl ester (2.1 g, 6.09 mmol) and PPh3 (1.597 g, 6.09 mmol) in THF (20 mL) was stirred at rt for 30 min. The reaction mixture was evaporated to dryness, the residue was taken up with TBME and 10% aq. citric acid soln. The aq. phase was reextracted with TBME, the combined org. phases were washed with H2O. The combined aq. phases were basified using 2N aq. NaOH soln. and three times extracted with TBME. The combined org. phases were dried over Na2SO4, filtered and concentrated to yield 2-bromo-5-fluoro-4-(2-methyl-aziridin-2-yl)-pyridine in a mixture with Ph3PO that was used for the next step without further purification, HPLC RtH4=0.96 min; ESIMS: 231, 233 [(M+H)+].

Provenance & Evidence