Hydrochloric Acid → Triapenthenol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 12.5 g (70 mmols) of the (+)-antipode of N-methyl-ephedrine in 140 ml of absolute diethyl ether is added dropwise, at 20° C., to a stirred suspension of 2.7 g (70 mmols) of lithium aluminum hydride in 70 ml of diethyl ether. The mixture is heated under reflux for 30 minutes and then cooled to 20° C., 17 g (140 mmols) of N-ethylaniline are added dropwise, and the mixture is allowed to boil under reflux for one hour. Thereafter, the reaction mixture is cooled to -70° C. A solution of 5.2 g (20 mmols) of the (E)-isomer of 1-cyclohexyl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pent-1-ene-3-one in 50 ml of absolute diethyl ether is added dropwise at this temperature. Stirring is continued for a further 4 hours at -70° C., and the reaction mixture is then allowed to stand for a further 16 hours at - 70° C. Water is then added slowly. The resulting reaction mixture is acidified with 10% strength aqueous hydrochloric acid so that the pH value is about 4. Thereafter, the organic phase is separated off, and the aqueous phase is extracted twice with ethyl acetate. The combined organic phases are washed twice with 5% strength aqueous hydrochloric acid, dried over magnesium sulphate and then evaporated down under reduced pressure. The crystalline residue which remains is stirred with cyclohexane, and the product is filtered off under suction, washed with cyclohexane and dried. 3.2 g (61% of theory) of the (+)-antipode of (E)-1-cyclohexyl-4,4-dimethyl-3-hydroxy-2-(1,2,4-triazol-1-yl)-pent-1-ene are obtained in the form of a crystalline product in this manner.

Herkunft & Nachweise