反应详情

Et2O (40 mL) was added to compound 6b (1.48 g, 2.74 mmol) to form a yellow suspension. At −80° C. an Et2O (5 mL) solution of 2-isopropylphenyllithium (0.690 g, 5.47 mmol) was added dropwise over 5 minutes. Upon the start of the addition the mixture became dark purple. The mixture was allowed to slowly warm to ambient temperature while stirring overnight. Then water was added (30 mL) and the yellow organic layer was separated and dried with brine. Further drying over MgSO4 followed by filtration and evaporation afforded crude diamine 7p as a yellow oil that was found by 1H NMR spectroscopy to be contaminated with about 10% of the imine 6b. The product was purified on basic alumina eluted with 5:1 hexanes:dichloromethane, gradually increasing the amount of ethyl acetate to 8%. The product eluted just before the imine impurity. Yield: 1.5 g, 83%. The 1H NMR spectrum of 7p in CD2Cl2 solution is complex due to the presence of more than one diastereoisomer.

1. customto form a yellow suspension
2. additionUpon the start of the addition the mixture
3. customthe yellow organic layer was separated
4. dry with materialdried with brine
5. dry with materialFurther drying over MgSO4
6. filtrationfollowed by filtration and evaporation