Trifluoroacetic acid → (2S,5R)-5-(Benzyloxyamino)-1-(2,2,2-trifluoroacetyl)piperidine-2-carboxylic acid

Participants

Reaction Steps

A solution of (2S,5R)-tert-Butyl 5-(benzyloxyamino)-1-(2,2,2-trifluoroacetyl)piperidine-2-carboxylate (1.50 g, 3.73 mmol) in methylene chloride (5.0 mL) was ice-cooled, and trifluoroacetic acid (5.0 mL) was added, and reacted at the same temperature for 30 min. and then at room temperature for 2 h. The reaction mixture was concentrated under reduced pressure, then water and 6.5% sodium bicarbonate aqueous solution was added to the residue. After pH was adjusted to ca. pH 8, aqueous layer was washed with ethyl acetate. To this aqueous layer was added 5% potassium hydrogen sulfate aqueous solution. After pH was adjusted to ca. pH 5.6, the aqueous layer was extracted with ethyl acetate. After the organic layer was washed with saturated brine, dehydrated over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to afford 0.913 g of the title compound (yield 71%).

Provenance & Evidence