反应详情

温度

-10 °C

A solution of DL-tryptophan methyl esterbenzaldimine (4.0 g, 13 mmol) in 30 mL THF was added over 15 minutes to a mixture of 20.2 mL lithiumdiisopropylamide (10% suspension in hexan) and 70 mL dry THF, cooled to -10° C. under nitrogen atmosphere. The stirring was continued for an additional 45 minutes, keeping the temperature at -10° C. A solution of trimethylsilylethoxymethylchloride (2.2 g, 13.2 mmol) in 5 mL THF was added and the mixture stirred overnight at room temperature. The reaction mixture was decomposed with 100 mL distilled water, extracted with ethyl acetate (3×100 mL), and the organic solvent was removed in vacuo. The resulting oily residue was treated with 30 mL IN hydrochloric acid for 1 hour at room temperature after which the reaction mixture was made basic with sodium bicarbonate and extracted with ethyl acetate (3×100 mL). The organic layer was dried over Na2SO4, evaporated to give the crude product which was separated by flash chromatography on silica gel using a mixture of toluene/ethanol 500:30 (v/v) as elution solvent. The fractions, containing the main product (TLC on silica gel, toluene/ethanol 10:2 (v/v), Rf 0.38) were combined and evaporated to dryness in vacuo. Trituration of the oily residue with diethyl ether gave 2.0 g (44%) of α-trimethylsilylethoxymethyl-DL-tryptophan methyl ester, mp 113°-115° C.

1. customat -10° C
2. distillationdistilled water
3. extractionextracted with ethyl acetate (3×100 mL)
4. customthe organic solvent was removed in vacuo
5. additionThe resulting oily residue was treated with 30 mL IN hydrochloric acid for 1 hour at room temperature after which the reaction mixture
6. extractionextracted with ethyl acetate (3×100 mL)
7. dry with materialThe organic layer was dried over Na2SO4
8. customevaporated
9. customto give the crude product which
10. customwas separated by flash chromatography on silica gel using
11. additiona mixture of toluene/ethanol 500:30 (v/v)
12. washas elution solvent
13. additionThe fractions, containing the main product (TLC on silica gel, toluene/ethanol 10:2 (v/v), Rf 0.38)
14. customevaporated to dryness in vacuo