反应详情

To (9) (5 mmol) dissolved in dry ethanol (25 ml) at 5° C. was added sodium ethoxide (0.37 g, 5.2 mmol). The mixture was stirred at this temperature for 1 h, and then at room temperature under TLC control. After completion of the reaction (˜2-3 h) [if the reaction was not completed by this time, the mixture was further refluxed for an additional 1-2 h], water (100 ml) was slowly added followed by a drop-wise addition of 1.0 N hydrochloric acid (6 ml) with stirring. After 30 minutes at 5° C., the crystals were collected by filtration, washed with water, and dried at 40° C. under vacuum to give (1) in 79% yield with an assay of 98.6%.

1. customat room temperature
2. customAfter completion of the reaction (˜2-3 h) [if the reaction
3. additionwas slowly added
4. stirringwith stirring
5. waitAfter 30 minutes at 5° C.
6. filtrationthe crystals were collected by filtration
7. washwashed with water
8. customdried at 40° C. under vacuum