Formaldehyde → HCID 178527655, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of dibenzyl phosphite 50.2 (100 g, 381 mmol) and formaldehyde (37% in water, 65 mL, 860 mmol) in THF (200 mL) was added TEA (5 mL, 36 mmol). The resulted mixture was stirred for 1 h, and then concentrated under reduced pressure. The residue was dissolved in methylene chloride and hexane (1:1, 300 mL), dried over sodium sulfate, filtered through a pad of silica gel (600 g) and eluted with ethyl acetate and hexane (1:1). The filtrate was concentrated under reduced pressure. The residue 50.3 (95 g) was dissolved in methylene chloride (800 mL), cooled to −78° C. and then charged with pyridine (53 mL, 650 mmol). To this cooled solution was slowly added trifluoromethanesulfonic anhydride (120 g, 423 mmol). The resulted reaction mixture was stirred and gradually warmed up to −15° C. over 1.5 h period of time. The reaction mixture was cooled down to about −50° C., diluted with hexane-ethyl acetate (2:1, 500 mL) and quenched with aqueous phosphoric acid (1M, 100 mL) at −10° C. to 0° C. The mixture diluted with hexane-ethyl acetate (2:1, 1000 mL). The organic phase was washed with water, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on silica gel to afford dibenzyl triflate 3.11 (66 g, 41%) as a colorless oil.

Provenance & Evidence