Acetic Anhydride → 2-Acetamido-3-methoxypropanoic acid

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Reaction Steps

In a vessel, equipped with a mechanical stirrer, add at 20° C., 1.0 eq. of O-methyl-D,L-serine. Add 6 volumes of tetrahydrofuran and 0.65 volume of water. Add dropwise in 5 minutes 1.2 eq. of acetic anhydride. Stir mechanically the white suspension until complete conversion (HPLC monitoring, typical reaction time: 16 hours). At the end of the reaction the mixture becomes homogenous. Remove tetrahydrofuran as well as water azeotropically. Add toluene in order to remove completely water and acetic acid (KF and GC control). Crystallize the obtained crude solid in 6 volumes of acetone. Dry the wet solid at 40° C. under vacuum overnight. N-acetyl-O-methyl-D,L-serine (IX) is obtained as a white solid in 80% yield with a chemical purity of greater than 99% measured by HPLC.

Provenance & Evidence