Triethylamine → (S)-3-(tert-Butoxycarbonylamino)pyrrolidin-1-yl-2,3,5,6-tetrafluorobenzoic acid benzyl ester

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Reaction Steps

A solution of 2,3,4,5,6-pentafluorobenzoic acid benzyl ester (Example 1d, 8.05 g, 26.6 mmol), triethylamine (26 mL, 186 mmol), and (S)-pyrrolidin-3-yl-carbamic acid tert-butyl ester (5.6 g, 30 mmol) in acetonitrile (150 mL) is stirred at room temperature for 24 hours. The solvent is removed under vacuum and the residue dissolved in chloroform, washed with NaHCO3 and then brine, dried over Na2SO4, filtered, and concentrated in vacuo to afford a solid. The solid is then purified by column chromatography (1:1:6 ethyl acetate/chloroform/hexanes) to yield the title compound as a solid (7.92 g). 1H NMR (CDCl3): δ 7.48–7.30 (m, 5H), 5.35 (s, 2H), 4.77–4.50 (m, 1H), 4.37–4.19 (m, 1H), 4.01–3.63 (m, 3H), 3.59–3.46 (m, 1H), 2.29–2.09 (m, 1H), 2.01–1.82 (m, 1H), 1.45 (s, 9H).

Provenance & Evidence