反应详情

温度

50 °C

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (21.2 g; 122 mmoles, described in Example 3) and sodium borohydride (7.40 g, 195 mmoles) are dissolved in dried redistilled diglyme (100 ml). The solution is cooled, with stirring, under nitrogen and maintained at 0° C. during dropwise addition of a solution of boron trifluoride etherate (32 ml; 250 mmoles) in diglyme (15 ml). When the addition is complete, the mixture is stirred for 1.5 hours at room temperature. Water (10 ml) is added followed by 6N sodium hydroxide solution (30 ml). The temperature is raised to 50° C. followed by dropwise addition of 30% hydrogen peroxide solution (30 ml, 260 mmoles) over a period of 1 hour. Conc. hydrochloric acid (30 ml) is added, and the solvents are evaporated. The residue is redissolved in water and the evaporation is repeated. The residue is dissolved in water, basified with potassium carbonate solution, and the free base is extracted with ether. The extract is dried (Na2SO4), evaporated, and the residual yellow oil is distilled under reduced pressure. The material distilling at 115°-128° C./0.1 mm is crystallized from hexane to give the title compound, mp 78°-79.5° C. (R. E. Lyle et al, supra, reported mp 82°-84° C.).

1. customin dried
2. distillationredistilled diglyme (100 ml)
3. temperatureThe solution is cooled
4. additionWhen the addition
5. stirringthe mixture is stirred for 1.5 hours at room temperature
6. customthe solvents are evaporated
7. dissolutionThe residue is redissolved in water
8. customthe evaporation
9. dissolutionThe residue is dissolved in water
10. extractionthe free base is extracted with ether
11. dry with materialThe extract is dried (Na2SO4)
12. customevaporated
13. distillationthe residual yellow oil is distilled under reduced pressure
14. distillationThe material distilling at 115°-128° C./0.1 mm
15. customis crystallized from hexane