反应详情

温度

-78 °C

Under argon, 3.7 g (12.24 mmol) of 7-cyclopentyl-5-methoxy-2,2-dimethyl-4-oxochroman-6-carbaldehyde (Example 6A) are suspended in 150 ml of tetrahydrofuran and cooled to −78° C. 29.4 ml (14.68 mmol) of a freshly prepared 0.5 M solution of bromo[4-(trifluoro-methyl)phenyl]magnesium in tetrahydrofuran are added slowly. The mixture is then warmed to −20° C. and stirred at this temperature for 30 min. At −20° C., another 12.3 ml (6.15 mmol) of the above Grignard solution are added, and the mixture is stirred for a further 45 min. The mixture is then hydrolyzed using 5% strength sodium bicarbonate solution and then extracted repeatedly with ethyl acetate. The combined organic phases are washed twice with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated. The crude product is chromatographed on silica gel (mobile phase: cyclohexane/ethyl acetate 20:1→2:1). This gives 2.35 g (43% of theory) of the title compound.

1. temperatureThe mixture is then warmed to −20° C.
2. additionAt −20° C., another 12.3 ml (6.15 mmol) of the above Grignard solution are added
3. stirringthe mixture is stirred for a further 45 min
4. extractionextracted repeatedly with ethyl acetate
5. washThe combined organic phases are washed twice with saturated sodium chloride solution
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude product is chromatographed on silica gel (mobile phase: cyclohexane/ethyl acetate 20:1→2:1)