反应详情

温度

-78 °C

Under argon and at −78° C., 4 ml (9.95 mmol) of a 2.5 M solution of n-butyllithium in a hexane fraction were added dropwise to a solution of 1.0 g (4.97 mmol) of 3-bromobenzoic acid in 20 ml of anhydrous THF. After 20 min, 730 μl (9.95 mmol) of acetone were added dropwise at the same temperature. The reaction mixture was stirred at −78° C. for a further hour and then allowed to warm to RT over the course of about 1 h. The reaction mixture was then hydrolysed by careful addition of a few drops of saturated aqueous ammonium chloride solution. The mixture was diluted with 200 ml of water and extracted five times with in each case about 25 ml of ethyl acetate. The combined organic extracts were washed with saturated aqueous sodium chloride solution, dried over magnesium sulphate, filtered and freed from the solvent on a rotary evaporator. The residue obtained was purified in four portions by preparative HPLC (Method 36). Pooling of the product fractions, evaporation and drying under high vacuum gave 356 mg (39% of theory) of the title compound.

1. temperatureto warm to RT over the course of about 1 h
2. extractionextracted five times with in each case about 25 ml of ethyl acetate
3. washThe combined organic extracts were washed with saturated aqueous sodium chloride solution
4. dry with materialdried over magnesium sulphate
5. filtrationfiltered
6. customfreed from the solvent on a rotary evaporator
7. customThe residue obtained
8. customwas purified in four portions by preparative HPLC (Method 36)
9. customPooling of the product fractions, evaporation
10. customdrying under high vacuum