4-Nitrobenzoic Acid → Benzyl trans-3-fluoro-4-[(4-nitrobenzyl)oxy]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of triphenylphosphine (120.1 g, 0.458 mol) in THF (2 L) was added DIAD (92.6 g, 0.458 mol) with stirring under nitrogen at 0° C. The resulting suspension was stirred for 40 min, and then a solution of benzyl cis-3-fluoro-4-hydroxypiperidine-1-carboxylate (58 g, 0.229 mol) and 4-nitrobenzoic acid (45.9 g, 0.275 mol) in THF was added slowly over 1.5 h. The resulting orange solution was allowed to warm to room temperature and stirred for 48 h. The mixture was concentrated under reduced pressure to a crude oil was purified by column chromatography (EtOAc:petroleum ether=1:40) to afford benzyl trans-3-fluoro-4-[(4-nitrobenzyl)oxy]piperidine-1-carboxylate as an off-white solid.

Provenance & Evidence