反应详情

温度

3 °C

The product from Step 3 (5.0 g) was dissolved in dry dichloromethane (200 ml), cooled to 3° C. with stirring then 2-bromobutyryl bromide (6.25 g) was added followed by dropwise addition of dry triethylamine (10.93 ml), maintaining the reaction at 5° C. The suspension, which had formed during the reaction, was stirred at ambient temperature for 1 hour then water was added. The organic phase was separated, washed with water, dried over magnesium sulphate then evaporated under reduced pressure. The residue was fractionated by chromatography (silica; hexane/diethyl ether, 3:1 by volume) to give the required product, 5.2 g, as a colourless solid, m.p. 79–81° C.

1. temperaturemaintaining
2. customthe reaction at 5° C
3. customThe suspension, which had formed during the reaction
4. stirringwas stirred at ambient temperature for 1 hour
5. customThe organic phase was separated
6. washwashed with water
7. dry with materialdried over magnesium sulphate
8. customthen evaporated under reduced pressure