Sodium Hydroxide → 3-Aminoazepan-2-one hydrochloride

Participants

Reaction Steps

A stirred mixture of L-lysine hydrochloride 1 (55 g, 300 mmol) and NaOH (12 g, 300 mmol) in hexanol (1.2 L) is heated to reflux with a Dean-Stark trap used to remove H2O. The suspension is refluxed for 8 hours until all starting material is consumed (which maybe determined by 1H NMR). The suspension is then cooled and filtered to remove byproduct NaCl. The filtrate is concentrated and the resulting crude α-amino-ε-caprolactam 2 is dissolved in water. After acidification to pH 6 with addition of concentrated HCl and partial concentration, crystals maybe formed at room temperature to afford α-amino-ε-caprolactam hydrochloride (37 g) in 75% yield.

Provenance & Evidence