Hydrochloric Acid → 1-Cyclohexyl-4-dimethylamino-2-phenyl-2-buten-1-ol

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Reaction Conditions

Reaction Steps

Phosphorus oxychloride (2.5 cc) dissolved in methylene chloride (6 cc) is added dropwise at 0° C. to a solution of 3-dimethylaminoacrylophenone (5 g) in methylene chloride (16 cc). After stirring for 15 minutes at 0° C. and then 30 minutes at 20° C., the temperature is again brought down to 0° C. The precipitate formed is dissolved by adding methanol (5 cc). Triethylamine (8 cc) and thiophenol (3.15 cc) dissolved in methylene chloride (10 cc) are added dropwise. After 2 hours 30 minutes' stirring at 20° C., methanol (30 cc) is added followed by sodium cyanoborohydride (1 g) at 0° C. and stirring is continued for 3 hours at 20° C. The mixture is then concentrated under reduced pressure (2.7 kPa) at 40° C. The solid obtained is taken up in chloroform and the solution is filtered. The organic phase is evaporated under reduced pressure (2.7 kPa) at 40° C. The residue obtained is taken up in water and the solution is made alkaline to pH 10 by adding a 35% strength aqueous solution of sodium hydroxide, and then extracted with methylene chloride. The organic phase is dried over sodium sulphate, filtered and then evaporated to dryness under reduced pressure (2.7 kPa) at 40° C. The residue obtained is dissolved in ethyl ether (10 cc). A 3N solution (10 cc) of hydrochloric acid gas in ethyl ether is added to the solution obtained. The precipitate formed is separated off by filtration and then recrystallised from a mixture of ethanol (15 cc) and ethyl ether (20 cc). In this way 1-dimethylamino-3-phenyl-3-phenylthio-2-propene (Z) hydrochloride (3 g) is obtained in the form of white crystals melting at 176° C.

Provenance & Evidence