The Synthesis ofα-Methylamino Acids

Convenient Synthesis of α-Difluoromethylornithine

“…NaHC0 3 and brine, dried over MgS04 and evaporated. The residue was purified by column chromatography on silica gel, using (4) A mixture of 3 (7.30g, 33.8mmol) and 2N HCI (IOOml) in methanol (50ml) was stirred at 4O-50°C for 1 h. After removing the solvent, the residue was washed with AcOEt. The aqueous layer was concentrated in vacuo, and the crystals that appeared were washed with THF to afford 4 as colorless crystals (6.0g, 66%), mp 174-175°C.…”

“…As part of our investigation to develop biologically active products from amino acids, we have already reported the synthesis of IX-methylamino acids by the electrophilic alkylation of lX-isocyanocarboxylates. 4 ) As an extension of this, we carried out the synthesis of IX-difiuoromethylornithine (5) by IX-difluoromethylation, using methyl 2,5-dilsocyanopentanoate (2).…”