Synthesis of 2-Aminocarboxylic Acids on the Basis of Metalated Lithium Acylates

Abstract

2-Aminocarboxylic acids have been synthesized through the reaction of lithium acylate α-carbanions with alkyl nitrites to form α-hydroxyiminoacylates, followed by reduction of the latter with tin chloride. The reactions of lithium acylate α-carbanions, generated by the metalation of carboxylic acids with lithium diisopropylamide at 35–40°С in THF under argon, with alkyl nitrites at 45–50°С give 2-hydroxyiminocarboxylic acids in 55–97% yields. The reduction of 2-hydroxyiminocarboxylic acids with tin(II) chloride in conc. HCl at 20–25°С leads to 2-aminocarboxylic acid hydrochlorides in 52–94% yields.