反应详情

A solution of enaminoketone 3b (327 mg, 1.00 mmol) in abs. EtOH (10 mL) was cooled to 0° C. and hydrazine monohydrogen chloride was added in one portion. The mixture was stirred for 18 h during which time the temperature reached rt after 2 h. The mixture was concentrated and the residue partitioned with deionized H2O and EtOAc. The organic layer was removed and the aqueous portion extracted with EtOAc (2×). The combined EtOAc portions were washed with brine, dried over MgSO4 and filtered through a SiO2 plug capped with a MgSO4 layer (EtOAc for elution). The solution was concentrated give the title compound 4b as a brittle white foam crushed to a white solid; 253 mg, 87%, MS m/z 240.0, 194.0 (ESI+, M−tBu, M−Boc).

1. waitreached rt after 2 h
2. concentrationThe mixture was concentrated
3. customthe residue partitioned with deionized H2O and EtOAc
4. customThe organic layer was removed
5. extractionthe aqueous portion extracted with EtOAc (2×)
6. washThe combined EtOAc portions were washed with brine
7. dry with materialdried over MgSO4
8. filtrationfiltered through a SiO2 plug
9. customcapped with a MgSO4 layer (EtOAc for elution)
10. concentrationThe solution was concentrated