Reaktion #10376

Reaktionsgleichung

2,3,4,6-tetrafluorobenzoic acid ethyl ester

triethylamine

(S)-pyrrolidin-3-ylcarbamic acid tert-butyl ester

→

title compound

Ausbeute 69.8%

4-[(S)-3-tert-Butoxycarbonylaminopyrrolodin-1-yl]-2,3,6-trifluorobenzoic acid ethyl ester

Ausbeute 69.8%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe mixture is concentrated in vacuo
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 under vacuum
7. 7
   Sonstigeto afford a solid
8. 8
   SonstigeThe solid is purified by column chromatography (1:1:7 ethyl acetate/chloroform/hexanes)

Vorschrift

A solution of 2,3,4,6-tetrafluorobenzoic acid ethyl ester (Example 1b, 5.1 g, 22.9 mmol), triethylamine (22 mL, 157 mmol), and (S)-pyrrolidin-3-ylcarbamic acid tert-butyl ester (5.2 g, 27.9 mmol) in acetonitrile (60 mL) is stirred at room temperature for 64 hours. The mixture is concentrated in vacuo and the residue dissolved in chloroform, washed with NaHCO3 and then brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford a solid. The solid is purified by column chromatography (1:1:7 ethyl acetate/chloroform/hexanes) to afford the title compound (6.21 g). 1H NMR (CDCl3): δ 6.07 (ddd, 1H), 4.78–4.63 (bd, 1H), 4.49–4.22 (m, 3H), 3.80–3.68 (m, 1H), 3.66–3.28 (m, 3H), 2.33–2.13 (m, 1H), 2.04–1.83 (m, 1H), 1.45 (s, 9H), 1.36 (t, 3H).

Quelle