Chloroacetaldehyde → 2-[Benzyl-(2-chloro-ethyl)-amino]-propionic acid ethyl ester

関与物質

反応条件

反応手順

To a solution of 2-benzylamino-propionic acid ethyl ester (1 eq.) in dry DCM was added MgSO4 (0.75 eq.). The reaction was cooled to 0° C. then the above solution of chloroacetaldehyde in dry DCM (solution I) and acetic acid (1 eq.) were added. Sodium triacetoxyborohydride (1.5 eq.) was added portionwise. The reaction was stirred for 1 h at 0° C. The crude was carefully quenched with a saturated aqueous solution of NaHCO3. Then aqueous NaOH (2N) was added. The aqueous layer was extracted with DCM. The combined organic layers were washed with an aqueous saturated solution of NaHCO3, then dried over MgSO4 and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (elution with heptane/EtOAc 98/2 to 95/5) to afford 2-[benzyl-(2-chloro-ethyl)-amino]-propionic acid ethyl ester.

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