反应详情

温度

25 °C

A mixture of tert-butyl 3-oxopyrrolidine-1-carboxylate 45-1 (0.32 g, 1.73 mmol)), benzyl piperazine-1-carboxylate 45-2 (0.38 g, 1.73 mmol) and titanium tetraisopropoxide (0.61 g, 2.16 mmol) were stirred at 25° C. for 1 hour. Then the viscous solution was diluted with 2 mL of absolute ethanol and sodium cyanoborohydride (0.073 g, 1.16 mmol) was added. After stirring for 18 hours at 25° C., 1 mL of water was added and the solids filtered off. The filtrate was then dried under reduced pressure, redissolved in ethyl acetate, refiltered and evaporated. This material was purified on a silica column and then treated with trifluoroacetic acid to afford 45-3. 1H-NMR (CDCl3): 7.36(m, 5H); 5.13(s, 2H); 3.55(m, 4H); 3.26(m, 1H); 3.08(m, 1H); 2.80(m, 1H); 2.62(m, 1H); 2.49(m, 2H); 2.41(m, 2H); 2.08(m, 2H); 1.75(m, 1H).

1. additionwas added
2. stirringAfter stirring for 18 hours at 25° C.
3. filtrationthe solids filtered off
4. customThe filtrate was then dried under reduced pressure
5. dissolutionredissolved in ethyl acetate
6. customevaporated
7. customThis material was purified on a silica column
8. additiontreated with trifluoroacetic acid
9. customto afford 45-3