反应详情

Racemic (3R*,4S*)-3-azido-4-hydroxychroman-7-carbonitrile Int-2-C (5.08 g, 23.5 mmol) and hydroxylamine hydrochloride (3.27 g, 47.0 mmol) were mixed in 2-propanol (94.0 mL). To this suspension was added sodium bicarbonate (7.90 g, 94.0 mmol) and the resulting mixture was heated at reflux for 2 h. After the reaction mixture was cooled to room temperature, it was diluted with EtOAc (250 mL) and washed with water and brine. The combined aqueous layers were extracted again with EtOAc. The combined organic layers were dried (MgSO4) and concentrated to afford racemic (3R*,4S*,E/Z)-3-azido-N′,4-dihydroxychroman-7-carboximidamide Int-2-D (5.71 g, 22.9 mmol, 97.5% yield): LCMS=250.08 [M+H]+.

1. temperaturethe resulting mixture was heated
2. temperatureat reflux for 2 h
3. washwashed with water and brine
4. extractionThe combined aqueous layers were extracted again with EtOAc
5. dry with materialThe combined organic layers were dried (MgSO4)
6. concentrationconcentrated