反应详情

Under a nitrogen atmosphere a solution of 1.41 g (5.3 mmol) of the Example 3 compound in 15 ml of methylene chloride is stirred in an ice bath while a solution of 1.2 g (7.9 mmol) hexamethyldisilazane in 10 ml methylene chloride is added dropwise. The solution is allowed to warm to room temperature at which temperature stirring is continued for 18 hours. The solution is then evaporated in vacuo to an oil which is redissolved in 20 ml of a mixture of methylene chloride (15)-ethanol (5). After stirring at room temperature for one hour, the solution is again concentrated in vacuo, leaving a solid, 1.1 g (85%), mp 163°-165°. Recrystallization from ethyl acetate provides analytically pure title compound, mp 172.5°-173°.

1. additionis added dropwise
2. customThe solution is then evaporated in vacuo to an oil which
3. dissolutionis redissolved in 20 ml of a mixture of methylene chloride (15)-ethanol (5)
4. stirringAfter stirring at room temperature for one hour
5. concentrationthe solution is again concentrated in vacuo
6. customleaving a solid, 1.1 g (85%), mp 163°-165°
7. customRecrystallization from ethyl acetate