A conventional new procedure for N-acylation of unprotected amino acids.
The preparation of amide derivatives (4) by N-acylation of unprotected alpha-amino acids is easily achieved via readily available benzotriazolyl carboxylates (2a-d) or succinimidyl carboxylates (2e-f). These intermediates (2) are prepared from reaction of carboxylic acids (1) with 1-hydroxybenzotriazole (HO-Bt) or N-hydroxysuccinimide (HO-Su) in the presence of equimolar amounts of 1-ethyl-3-(3'-dimethylaminopropyl)carbodiimide hydrochloride (WSCI). The overall yields of the target compounds (4) were excellent, and this two-stage procedure could be applicable as an alternative procedure for one-pot reaction.
Fujisaki
Fumiko
F
Pharmaceutical Sciences, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
Oishi
Marumi
M
Sumoto
Kunihiro
K
D000215:Acylation; D000596:Amino Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared
D000596:Amino Acids