Reaktion #10378

Reaktionsgleichung

2,3,4,5,6-pentafluorobenzoic acid benzyl ester

triethylamine

(S)-pyrrolidin-3-yl-carbamic acid tert-butyl ester

→

title compound

Ausbeute 63.6%

4-[(S)-3-(tert-Butoxycarbonylamino)pyrrolidin-1-yl]-2,3,5,6-tetrafluorobenzoic acid benzyl ester

Ausbeute 63.6%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent is removed under vacuum
2. 2
   workup.DISSOLUTIONthe residue dissolved in chloroform
3. 3
   Waschenwashed with NaHCO3
4. 4
   Trocknenbrine, dried over Na2SO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo
7. 7
   Sonstigeto afford a solid
8. 8
   SonstigeThe solid is then purified by column chromatography (1:1:6 ethyl acetate/chloroform/hexanes)

Vorschrift

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).

Quelle