反应详情

温度

-70 °C

A solution of 2-[benzyl-(2-chloro-ethyl)-amino]-propionic acid ethyl ester (1 eq.) in dry THF was cooled to −78° C. under nitrogen. KHMDS (15% w/w in toluene) (1.25 eq.) was slowly added so that temperature was kept below −65° C. The reaction was stirred for 1 h at −70° C. Then acetic acid (0.3 eq.) was added. The reaction was warmed to 20° C. and stirred for 10 min, then quenched with a saturated aqueous solution of NaHCO3 and partially concentrated under reduced pressure. The crude was extracted twice with DCM. The organic layers were combined, dried over MgSO4, filtered and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (elution with heptane/EtOAc 1/0 then 95/5) to afford 1-benzyl-2-methyl-azetidine-2-carboxylic acid ethyl ester.

1. customwas kept below −65° C
2. temperatureThe reaction was warmed to 20° C.
3. stirringstirred for 10 min
4. customquenched with a saturated aqueous solution of NaHCO3
5. concentrationpartially concentrated under reduced pressure
6. extractionThe crude was extracted twice with DCM
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe crude was purified by chromatography on silica gel (
11. washelution with heptane/EtOAc 1/0