反应详情

温度

90 °C

10.0 g of lithium aluminum hydride are placed in 200 ml of absolute tetrahydrofuran under a nitrogen atmosphere in a 1.5 liter sulfonation flask provided with reflux condenser, thermometer, stirrer and dropping funnel, and there is added dropwise while stirring within about 1 hour a solution of 42 g of 1-(m-methoxyphenyl)-N,N-dimethyl-2-cyclohexene-1-acetamide in 450 ml of absolute tetrahydrofuran in such a manner that the temperature does not exceed 30° C. Subsequently, the mixture is stirred overnight at an oil-bath temperature of 90° C., cooled to room temperature and treated first dropwise with 50 ml of ethanol and then with tetrahydrofuran/water (1:1) until the further addition of this mixture no longer gives rise to an exothermic reaction. The mixture is then treated with 50 g of potassium carbonate, whereupon the separated precipitate is removed by filtration under suction and rinsed with methylene chloride. After distillation of the solvent, the brown oil obtained is treated with 200 ml of 1 N hydrochloric acid and extracted twice with 500 ml of ether each time. The ethereal solution is washed once with 100 ml of water. The aqueous phases are combined and made alkaline by the addition of concentrated ammonium hydroxide solution while cooling with ice. The separated base is taken up twice in 500 ml of ether each time. The organic phase is washed twice with 50 ml portions of sodium chloride solution and dried over magnesium sulfate. Thereafter, the solvent is removed by distillation. The oil obtained is chromatographed on 400 g of neutral aluminium oxide. Elution with 2500 ml of toluene gives rac. 1-(m-methoxyphenyl)-N,N-dimethyl-2-cyclohexene-1-ethylamine in the form of a colorless oil which is dissolved in 200 ml of ethanol and treated with an excess of ethanolic hydrochloric acid. After distillation of the solvent, the residue is treated twice with a mixture of 100 ml of ethanol and 100 ml of toluene. Then, the solvent is removed by distillation in a water-jet vacuum. The crystals obtained are dissolved in ethyl acetate/ethanol (20:1) at boiling temperature. After standing for 6 hours, the separated crystals are removed by filtration under suction, and there is obtained rac. 1-(m-methoxyphenyl)-N,N-dimethyl-2-cyclohexene-1-ethylamine hydrochloride in the form of colorless crystals having a melting point of 161°-162° C.

1. customprovided
2. temperaturewith reflux condenser
3. customthermometer, stirrer and dropping
4. additionfunnel, and there is added dropwise
5. customdoes not exceed 30° C
6. temperaturecooled to room temperature
7. customto an exothermic reaction
8. customis removed by filtration under suction
9. washrinsed with methylene chloride
10. distillationAfter distillation of the solvent
11. customthe brown oil obtained
12. extractionextracted twice with 500 ml of ether each time
13. washThe ethereal solution is washed once with 100 ml of water
14. additionby the addition of concentrated ammonium hydroxide solution
15. temperaturewhile cooling with ice
16. washThe organic phase is washed twice with 50 ml portions of sodium chloride solution
17. dry with materialdried over magnesium sulfate
18. customThereafter, the solvent is removed by distillation
19. customThe oil obtained
20. customis chromatographed on 400 g of neutral aluminium oxide
21. washElution with 2500 ml of toluene