Ninhydrin → (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate

Participants

Reaction Steps

To a solution of N-Boc-L-alanine (1.0 Kg, 5.29 mol, 1.0 equiv), in DCM (15 L) was added carbonyldiimidazole (943 g, 5.81 mol, 1.1 equiv) and the resultant mixture was stirred for 1 h at rt. To this reaction mixture was added N,O-dimethylhydroxylamine hydrochloride (577 g, 5.92 mol, 1.12 equiv) and stirred at rt for 16 h. The reaction was monitored using TLC (Note: for TLC, ninhydrin stain was used to visualize the product). Another 800 g batch was combined with this batch prior to the work up. Upon completion DCM was evaporated in vacuo. The crude residue thus obtained was partitioned between EtOAc (30 L) and water (10 L). The organic layer was then washed with 1 N HCl (2×10.0 L), aq satd. NaHCO3 (2×15.0 L), brine (5 L), and dried over Na2SO4. The aq layer was back extracted with EtOAc (3×15.0 L) and the work up procedure was repeated. Evaporation of solvent in vacuo afforded (S)-tert-butyl 1-(methoxy(methyl)amino)-1-oxopropan-2-ylcarbamate as a white solid.

Provenance & Evidence