Benzaldehyde → 1-Cyclohexyl-4-dimethylamino-2-phenyl-2-buten-1-ol

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Reaction Conditions

Reaction Steps

A 1.5M solution (29 cc) of n-butyllithium in hexane is added to a solution of β-dimethylaminopropiophenone 2,4,6-triisopropylbenzenesulphonylhydrazone (9.15 g) in 1,2-dimethoxyethane (100 cc) kept under a nitrogen atmosphere at a temperature in the region of -75° C. The orange solution obtained is then stirred for 15 minutes at a temperature in the region of 0° C., and then cooled to a temperature in the region of -40° C. Benzaldehyde (2.2 cc) is then added, and then the reaction mixture is stirred for 1 hour at a temperature in the region of 20° C. A 1N aqueous solution (100 cc) of hydrochloric acid is then added with stirring, followed by ethyl ether (100 cc). The aqueous phase is separated; the organic phase is extracted with a 0.1N aqueous solution (25 cc) of hydrochloric acid. The aqueous phases are combined, washed with ether (2×50 cc) and then made alkaline to a pH in the region of 10 with sodium hydroxide solution, and then extracted with ethyl acetate (3×50 cc). The organic phases are combined, dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. In this way 4-dimethylamino-1,2-diphenyl-2-buten-1-ol (Z) (5.2 g) is obtained in the form of white crystals melting at 75° C.

Provenance & Evidence