Methylamine → HCID 57544617, compound

Participants

Reaction Conditions

Reaction Steps

A three-neck, 3 L flask was dried under N2, cooled, equipped with an overhead stirrer and charged with a solution of DCC (20.6 g, 0.1 mol) in CH2Cl2 (0.65 L). This was cooled to 0° C. and solid Boc-Ser-OH (20.06 g, 0.1 mole) was added in one portion. This mixture was stirred for 5 min. Methylamine (33% w/w solution in EtOH, 12.5 mL, 0.1 mol) was added dropwise over 10 min maintaining the internal temperature below 8° C. The reaction was stirred for an additional 10 min, the cooling bath was emptied, and the reaction was stirred for 12 h; LC-MS (3 min) tR=0.75 min, m/z 241 (M+Na) indicated full conversion. DMAP (1.0 g, 0.008 mol) then acetic anhydride (105.0 mL, 1.1 mol) were added using an external water bath to moderate the exotherm (internal temp <30° C.). The reaction was stirred for 60 min. Celite (25 g) and Et2O (1 L) were added, the mixture was cooled to 0° C. and filtered through a pad of Celite and then a pad of SiO2. The filtrate was evaporated under reduced pressure. The resulting oil was chased with tolulene (3×100 mL) and separated by chromatography on a SiO2 column to yield (2S)-3-acetoxy-2-(t-butoxycarbonylamino)-N-methylpropanamide (20.4 g, 78%). LC-MS (3 min) tR=0.75 min, m/z, 283 (M+Na).

Provenance & Evidence