反应详情

温度

-45 °C

To a solution of 500 mg. of the product of Example 1 in 50 ml. of anhydrous ether maintaining at -45° C. is added dropwise a solution of 0.060 ml. of boron trifluoride in 2.0 ml. of anhydrous ether. The reaction mixture is stirred at -45° C. for 10 minutes and then allowed to warm to -30° C. in 5 minutes. The reaction mixture is poured into a mixture of 20 ml. of cool saturated sodium bicarbonate solution and 30 ml. of ether. The ethereal solution is washed with an additional 20 ml. of saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate and filtered. The ether is removed to provide a yellow solid. The solid is recrystallized from acetonitrile to give 259 mg. of the desired product as yellow crystals, mp. 182°-184° C.

1. temperatureto warm to -30° C. in 5 minutes
2. additionThe reaction mixture is poured into a mixture of 20 ml
3. washThe ethereal solution is washed with an additional 20 ml
4. dry with materialof saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate
5. filtrationfiltered
6. customThe ether is removed
7. customto provide a yellow solid
8. customThe solid is recrystallized from acetonitrile
9. customto give 259 mg