反应详情

To a suspension of NaH (9.72 g, 243 mmol, 60% in mineral oil) in toluene (100 mL), ethoxycarbonylamino-acetic acid ethyl ester (38 g, 187 mmol) is added at 0° C. The reaction is left stirring for 5 h at the same temperature. At that point but-2-enoic acid ethyl ester (25.6 g, 224 mmol) is added and the reaction allowed to warm up to rt and stirred for further 2 h. Ethanol (30 mL) is added and the reaction is then evaporated. The crude 1-tert-butyl 3-ethyl 2-methyl-4-oxopyrrolidine-1,3-dicarboxylate is dissolved in EtOH (1500 mL), then formamidine acetate (343 g, 1189 mmol) is added followed by sodium ethoxide (47.2 g, 694 mmol). The reaction is left stirring at 90° C. for 8 h. The solvent is then removed and to the crude material a saturated solution of NH4Cl (200 mL) is added followed by DCM (1 L). The water layer is extracted two times with DCM. The organics are dried and evaporate. The crude product is separated by FCC (DCM/MeOH 100:0 to 90:10) to give the title compound. MS (ESI) m/z 252.2 (M+1).

1. additionis added at 0° C
2. waitThe reaction is left
3. stirringstirred for further 2 h
4. customthe reaction is then evaporated
5. dissolutionThe crude 1-tert-butyl 3-ethyl 2-methyl-4-oxopyrrolidine-1,3-dicarboxylate is dissolved in EtOH (1500 mL)
6. waitThe reaction is left
7. stirringstirring at 90° C. for 8 h
8. customThe solvent is then removed and to the crude material a saturated solution of NH4Cl (200 mL)
9. additionis added
10. extractionThe water layer is extracted two times with DCM
11. customThe organics are dried
12. customevaporate
13. customThe crude product is separated by FCC (DCM/MeOH 100:0 to 90:10)