反应详情

温度

-78 °C

200 mg (0.91 mmol) of the crude product from Example 40A are initially charged in 3.5 ml of dry diethyl ether and cooled to −78° C. 0.63 ml (1.00 mmol) of a 1.6 M solution of n-butyllithium in hexane are slowly added dropwise. The reaction mixture is stirred at −78° C. for 1 h. 0.21 ml (2.74 mmol) of N,N-dimethylformamide is then slowly added dropwise. The mixture is allowed to warm to RT and stirred at RT for another 1 h. The mixture is then poured into about 3 ml of water. The mixture is extracted three times with in each case 10 ml of diethyl ether. The combined organic phases are dried over magnesium sulfate and the solvent is removed on a rotary evaporator. The residue is purified by column chromatography on silica gel 60 (mobile phase gradient: cyclohexane/ethyl acetate 20:1→2:1).

1. temperatureto warm to RT
2. stirringstirred at RT for another 1 h
3. extractionThe mixture is extracted three times with in each case 10 ml of diethyl ether
4. dry with materialThe combined organic phases are dried over magnesium sulfate
5. customthe solvent is removed on a rotary evaporator
6. customThe residue is purified by column chromatography on silica gel 60 (mobile phase gradient: cyclohexane/ethyl acetate 20:1→2:1)