Syntheses of 12-aminododecanoic and 11-aminoundecanoic acids from vernolic acid |
| |
Authors: | Folahan O Ayorinde Erick Y Nana Pete D Nicely Anthony S Woods Elvis O Price Chukwuma P Nwaonicha |
| |
Affiliation: | (1) Department of Chemistry, Howard University, 525 College St., NW, 20059 Washington, DC |
| |
Abstract: | 12-Aminododecanoic acid and 11-aminoundecanoic acid, monomer precursors for nylon-12 and nylon-11, respectively, have been
synthesized from vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid via a reaction sequence that includes the formation of 12-oxododecanoic acid oxime. Saponification of vernonia oil, followed
by a low-temperature recrystallization at −20°C, gave 51% vernolic acid (97% purity, m.p. 23–25°C). Hydrogenation afforded
cis-12,13-epoxystearic acid (m.p. 52–54°C, lit. m.p. 52–54°C), which upon oxidation with periodic acid in tertiary butyl alcohol
gave 12-oxododecanoic acid with an isolated yield of 71.0%. Reaction of the oxoacid with hydroxylamine hydrochloride gave
12-oxododecanoic acid oxime, which was catalytically reduced to give 12-aminododecanoic acid with a yield greater than 85%
and a melting point of 184–186°C (lit. m.p. 185–187°C). 11-Aminoundecanoic acid was prepared from the 12-oxododecanoic acid
oxime via a three-step reaction sequence that involved a Beckmann rearrangement, Hofmann degradation, and hydrolysis. Thus, the aldoxime
acid was hydrolyzed in the presence of nickel acetate tetrahydrate to give 11-carbamoylundecanoic acid (48% yield, m.p. 129–131°C,
lit. m.p. 129–130°C). The amide was then treated with a solution of sodium methoxide and bromine at 70–80°C to give 11-(methoxycarbonylamino)undecanoic
acid at 75% yield (m.p. 84–86°C; elemental analysis, calculated for C13H25NO4: C, 60.19; H, 9.73; N, 5.40; O, 24.68%; found C, 60.02; H, 9.81; N, 5.26; O, 24.91%), which upon alkaline hydrolysis and
subsequent neutralization gave 11-aminoundecanoic acid at 34% yield (m.p. 189–192°C, lit. m.p. 190°C). Mass spectrometric
and 13C nuclear magnetic resonance data of the previously unreported 11-(methoxycarbonylamino)undecanoic acid is provided. |
| |
Keywords: | Aldoxime 12-aminododecanoic acid 11-aminoundecanoic acid Beckmann rearrangement cis-12 13-epoxy-cis-9-octadecenoic acid 12 13-epoxystearic acid 12-oxododecanoic acid 12-oxododecanoic acid oxime vernolic acid vernonia oil |
本文献已被 SpringerLink 等数据库收录! |
|