反应详情

A solution of ethyl 3-(2,2-dichloro-3-oxocyclobutyl)propanoate (10.49 g, 43.87 mmol) and ammonium chloride (12 g, 220 mmol) in methanol (310 mL, 7600 mmol) was treated in small portions with zinc powder (14 g, 220 mmol). The reaction mixture was heated at reflux for 3 h after which time GC indicated the reaction was complete. The reaction mixture was cooled to room temperature and was filtered through Celite, washing the pad with Et2O. The filtrate was concentrated in vacuo to afford pale yellow solution. The solution was diluted with 200 mL Et2O and washed with 100 mL water. The separated aqueous layer was back extracted with 100 mL Et2O and the combined organic phase was washed with 100 mL 1:1 water/brine, 50 mL water, and 150 mL saturated aqueous NaHCO3. The organic layer was dried over MgSO4, filtered and concentrated in vacuo to afford the title compound (4.49 g, 60%) as a pale yellow oil which was of sufficient purity for use in the next step: GC purity >95% (ret. time, 4.24 min).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 3 h after which time GC
3. filtrationwas filtered through Celite
4. washwashing the pad with Et2O
5. concentrationThe filtrate was concentrated in vacuo
6. customto afford pale yellow solution
7. washwashed with 100 mL water
8. extractionThe separated aqueous layer was back extracted with 100 mL Et2O
9. washthe combined organic phase was washed with 100 mL 1:1 water/brine, 50 mL water, and 150 mL saturated aqueous NaHCO3
10. dry with materialThe organic layer was dried over MgSO4
11. filtrationfiltered
12. concentrationconcentrated in vacuo