Reaktion #158064

Reaktionsgleichung

K2CO3

(S)-benzyl pyrrolidine-2-carboxylate hydrochloride

K2CO3

t-butyl bromoacetate

→

(S)-benzyl 1-(2-tert-butoxy-2-oxoethyl)pyrrolidine-2-carboxylate

Ausbeute 49.4%

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added
2. 2
   ExtraktionThe products are extracted with EtOAc
3. 3
   WaschenThe organic layer is washed twice with water and once with brine
4. 4
   Trocknendried over K2CO3
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated

Vorschrift

To a suspension of (S)-benzyl pyrrolidine-2-carboxylate hydrochloride (700 mg, 2.90 mmol) and K2CO3 (1201 mg, 8.69 mmol) in DMF (7 ml), t-butyl bromoacetate (0.535 ml, 3.62 mmol) is added. After stirring for 71 hours, aqueous K2CO3 (1.5 g of K2CO3/40 ml of H2O) is added to the reaction mixture. The products are extracted with EtOAc. The organic layer is washed twice with water and once with brine, dried over K2CO3, filtered, and concentrated to give (S)-benzyl 1-(2-tert-butoxy-2-oxoethyl)pyrrolidine-2-carboxylate (458 mg); HPLC retention time=1.38 minutes (condition D); MS (m+1)=320.2; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.44 (s, 9 H) 1.81-2.03 (m, 3 H) 2.13-2.14 (m, 1 H) 2.82-2.88 (m, 1 H) 3.13-3.17 (m, 1 H) 3.46 (A of AB, J=17.3 Hz, 1 H) 3.49 (B of AB, J=17.3 Hz, 1 H) 3.73 (dd, J=8.8 and 4.8 Hz, 1 H) 5.15 (A of AB, J=12.4 Hz, 1 H) 5.17 (B of AB, J=12.4 Hz, 1 H) 7.29-7.38 (m, 5 H).

Quelle