反应详情

To a mixture of 4-n-octylaniline (0.21 g; 1 mmol), tert-butyl 5-formyl-2,2-dimethyl-1,3-dioxan-5-ylcarbamate (Ooii et al, J. Org. Chem., 2004, 69, 7765; 0.26 g; 1 mmol) and NaBH(OAc)3 (0.3 g; 1.4 mmol) in 1,2-dichloroethane (3.5 ml) AcOH (0.06 ml; 1 mmol) was added at room temperature with stirring under N2. After stirring for 2 h, the mixture was diluted to 20 ml with Et2O, washed with 1.M NaOH (2×5 ml), brine and dried over anhydrous MgSO4 and filtered. The filtrate was evaporated to dryness under reduced pressure. The residue was dissolved in hexane (5 ml) and kept in the freezer (−18° C.) overnight. The crystals formed were filtered off, washed with small volume of hexane and dried to give the title compound (0.32 g; 71%), as colourless crystals. 1H-NMR (CDCl3) 6.96 (d, 2H, J=8.4 Hz); 6.58 (d, 2H, J=8.4 Hz); 4.84 (broad s, 1H); 4.01 (d, 2H, J=11.9); 3.85 (broad s, 1H); 3.8 (d, 2H, J=11.9 Hz); 3.44 (s, 2H); 2.46 (t, 2H, J=7.9 Hz); 1.5 (m, 2H); 1.45 (s, 3H); 1.43 (s, 9H); 1.42 (s, 3H); 1.26 (m, 10H); 0.86 (t, 2H, J=6.95 Hz).

1. additionwas added at room temperature
2. stirringAfter stirring for 2 h
3. washwashed with 1.M NaOH (2×5 ml), brine
4. dry with materialdried over anhydrous MgSO4
5. filtrationfiltered
6. customThe filtrate was evaporated to dryness under reduced pressure
7. dissolutionThe residue was dissolved in hexane (5 ml)
8. customkept in the freezer (−18° C.) overnight
9. customThe crystals formed
10. filtrationwere filtered off
11. washwashed with small volume of hexane
12. customdried