反应详情

Methanol (40 mL) and (E)-tert-butyl 2-(6-((2,6-diisopropylphenylimino)methyl)pyridin-2-yl)benzyl(phenyl)carbamate (12) (2.56 g (4.67 mmol) were combined to form a yellow suspension. Then some NaBH3CN (0.293 g, 4.66 mmol) was added followed by four drops of 88% formic acid. Then additional NaBH3CN (0.878 g, 14.0 mmol) was added in small portions over 5 minutes. The mixture was heated to reflux for 3 hours then evaporated to near dryness. Water (20 mL) and Et2O (40 mL) were then added followed by a CH2Cl2 (6 mL). The organics were separated, dried over brine then magnesium sulfate, filtered, and evaporated to a thick oil. Chloroform (25 mL) was then added to form a solution. Trifluoroacetic acid (10 mL) was added and the mixture was heated to reflux to cause gas evolution. After 45 minutes the mixture was cooled to ambient temperature and 3 M NaOH (60 mL) was added. The biphasic mixture was rapidly stirred for several minutes. The organics were separated, washed with water (50 mL) and brine (5 mL). The organics were then separated and dried over magnesium sulfate. Filtration and evaporation afforded the product as a thick oil that was dried thoroughly under reduced pressure at 65° C. Yield: 2.0 g, 95%). 1H NMR (CD2Cl2, 500 MHz): 7.77 (t, 1H), 7.39-7.58 (m, 5H), 7.31 (d, 1H), 7.02-7.12 (m, 5H), 6.63 (t, 1H), 6.58 (d, 2H), 4.62 (br, 1H), 4.41 (br, 2H), 4.23 (br, 1H), 3.97 (br, 1H), 3.35 (sept, 2H), 1.20 (d, 12H).

1. customto form a yellow suspension
2. temperatureThe mixture was heated
3. temperatureto reflux for 3 hours
4. customthen evaporated
5. additionWater (20 mL) and Et2O (40 mL) were then added
6. customThe organics were separated
7. dry with materialdried over brine
8. filtrationmagnesium sulfate, filtered
9. customevaporated to a thick oil
10. additionChloroform (25 mL) was then added
11. customto form a solution
12. temperaturethe mixture was heated
13. temperatureto reflux
14. customThe organics were separated
15. washwashed with water (50 mL) and brine (5 mL)
16. customThe organics were then separated
17. dry with materialdried over magnesium sulfate
18. filtrationFiltration and evaporation