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J Am Oil Chem Soc (2011) 88:1425–1430
N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine.
Amines from this oil are potential intermediates in the
production of unique surfactants. For characterization
purposes we also report the synthesis of a mixture of
quaternary ammonium salts with the predominant salt
being N,N,N-ethyl dimethyl-(12S,13R)-epoxy-cis-9-octa-
decenyl ammonium bromide derived from the aforemen-
tioned tertiary amine mixture.
(10 mg/mL CHCl3) and analyte solution {2 mg/mL H2O}
were mixed (70/30 lL) in 2-mL Eppendorf microcentri-
fuge tubes. After vortexing for 10 s, 1 lL of the sample
solution was deposited on the sample plate and then
allowed to evaporate at room temperature to enable
co-crystallization of matrix and analyte.
Transesterification of VO to VOME (1)
A previously reported procedure by Elhilo et al. [18] was
followed without modification for the conversion to the
methyl esters.
Experimental Procedures
Reagents
Amidation of VOME
Crude VO was acquired from International Exchange of
Trade and Technology Inc. (Culver, IN, USA). Sodium
methoxide in methanol, hexane, dimethylamine, diethyl
ether, lithium aluminum hydride, sodium sulfate, ethanol,
and, bromoethane were purchased from Sigma-Aldrich
Corp. (St. Louis, MO, USA).
To a 50-mL round-bottom flask equipped with a magnetic
stir bar, was added VOME (1) (3.12 g, 10.01 mmol), fol-
lowed by 10 mL of dimethylamine (1 M solution in
methanol), and 2.4 mL of sodium methoxide (25 wt%).
After 2 h of reflux, the reaction mix was quickly trans-
ferred to a 50-mL beaker and placed in an ice bath (0 ꢁC)
for 15 min and then allowed to solidify for 24 h. Next, the
solidified product was carefully washed with 5-mL ethanol.
A pale yellow solid (1.11 g, 34.23%) resulted. GC–MS
data revealed a mixture of palmitamide, oleamide, steara-
mide, and the major product vernolamide (2). The pseudo-
molecular ion for vernolamide (2) was at m/z 324 [M ? H]
with diagnostic ions at m/z 87, 210 [M-113], and 252
[M-71]. IR: 1,631.21 and 1,552.52 cm-1, 842.13 and
Instrumentation
Monitoring of reactions was with an Agilent 6890N gas
chromatograph interfaced with an Agilent 5973 inert mass
spectrometer. The interface oven was maintained at
250 ꢁC, the ionizer temperature setting was at 230 ꢁC,
using electron ionization (EI) with electron energy at
70 eV. High resolution capillary gas chromatography was
conducted with a Supelco fused-silica SPB-5 (15 m,
0.25 mm ID, 0.25 lm film) column (Bellefonte, PA, USA),
oven temperature was programmed from 50 to 300 ꢁC
(20 ꢁC/min), and helium was used as carrier gas with head
pressure 9.8 psi. IR spectra were collected on a Perkin
Elmer Spectrum 100 FTIR spectrometer. The 13C nuclear
magnetic resonance (13C NMR), proton nuclear magnetic
resonance (1H NMR), and DEPT-135 spectra were recor-
ded on a Bruker Avance 400 MHz spectrometer with either
chloroform-d (CDCl3) or deuterium oxide (D2O) as sol-
vent. For characterization purposes the quaternary ammo-
nium salts of the amine mixture were synthesized. The
molecular masses were determined by matrix-assisted laser
desorption/ionization time-of-flight mass spectrometry
(MALDI-TOFMS) using an Applied Biosystems Voyager-
DE STR BioSpectrometry Workstation equipped with a
two-stage acceleration ion source. Positive ion MALDI
spectra (200 summed acquisitions) were acquired in
delayed-extraction (150 ns) and reflector modes. The
acceleration voltage was 20 kV, the grid voltage at 75%,
nitrogen laser (337 nm, 3 ns pulse width), and low mass
gate at m/z 50. The matrix, meso-tetrakis(pentafluorophe-
nyl)porphyrin (F20TPP), was purchased from Sigma-
Aldrich Corp. (St. Louis, MO, USA). Matrix solution
1
821.71 cm-1. H: (MeOD) d 0.84 (t, 3H, CH3), 1.18–1.97
(m, 20H, 10 CH2), 2.17 (t, 2H, CH2C=O), 5.40–5.60 (m,
2H, CH=CH), 2.4 (m, 2H, CH2–CHOCH), 2.95 (broad, 2H,
epoxy, CHCH), 3.21 (s,6H, N(CH3)2); 13C: (D2O) d 13.9
(1C, CH3), 22.0–36.0 (10C, CH2), 37.4 (1C, CH2C=O),
37.8 (1C, CH2CHOCH), 55.8 (2C, N(CH3)2), 56.6 and
57.3 (2C, epoxy CHCH), 123.6 and 132.9 (2C, CH=CH),
174.3 (1C, C=O); DEPT-135: (D2O) d 13.80 (1C,CH3),
22.61–31.66 (10C, CH2), 56.38 and 56.74 (2C, epoxy,
CHCH), 123.57 and 132.68 (2C, CH=CH), 56.2 (2C,
N(CH3)2).
Reductive Amination of Vernonia Oil Amides
To a 100-mL round-bottom flask equipped with a magnetic
stir bar was added the amide mixture containing vernola-
mide (2) (0.513 g, 1.59 mmol), followed by trituration with
20 mL of diethyl ether after which an additional 30 mL of
diethyl ether was added. Then LAH (0.12 g, 3.18 mmol)
was added slowly, and refluxed for 30 min. The reaction
mixture was then allowed to cool to room temperature and
placed in an ice-water bath (0 ꢁC) while 20 mL of water
was added slowly. The solution was vacuum filtered and
the filtrate extracted with two 40-mL portions of diethyl
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