Methyl vinyl ketone → 4,4-Bis(3-fluorophenyl)cyclohexanone

Participants

Reaction Conditions

Reaction Steps

Butenone (50.4 cc) is added to a solution of bis(3-fluorophenyl)acetaldehyde (144.5 g) in ethyl ether (500 cc), and then, after cooling to 0° C., a solution of potassium hydroxide (13.9 g) in ethanol (89 cc) is added dropwise. The reaction mixture is stirred for 2 h at 0° C. and then for 16 hours at 25° C. and diluted with ethyl acetate (300 cc) and water (500 cc). The aqueous phase is washed with ethyl acetate (300 cc). The combined organic phases are washed with a saturated sodium chloride solution (500 cc), dried over magnesium sulphate and concentrated under reduced pressure (2.7 kPa). The residue is chromatographed (in two runs) on silica gel (particle size 0.04-0.063 mm, columns 8.5 cm in diameter, 34 cm high), eluting under a nitrogen pressure of 0.5 bar with a mixture of cyclohexane and ethyl acetate (90:10). 4,4-Bis(3-fluorophenyl)cyclohexanone (90.3 g) is obtained in the form of white crystals. M.p. 95° C.

Provenance & Evidence