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

1. additionwas added dropwise
2. customThe solution was then evaporated in vacuo to an oil which
3. dissolutionwas 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 was again concentrated in vacuo
6. customleaving a solid, 1.1 g (85%), mp 163°-165°
7. customRecrystallization from ethyl acetate