Formation of Tetrasubstituted Ammonium Salts from Tertiary Amines
FULL PAPERS
completed within 8 h. According to the kinetic profile, Catalytic Testing
the turnover frequency (TOF) of the reaction was
To a solution of a tertiary amine (2.87 mmol) in 1 mL of
CH2Cl2 (15.6 mmol) was added nickel oxide nanoparticles (5
mol%) or Raney nickel (5 mol%), and the reaction mixture
was stirred at 1008C for 10 h. A white precipitates appeared
as the reaction went on. After the reaction the mixture was
allowed to cool to room temperature, followed by filtration
to obtain the chloromethylated quaternary ammonium salts.
Nickel oxide or Raney nickel catalyst was recovered from
the product by centrifuge. The recovered nickel catalyst was
reused for the further catalytic reactions.
around 125 hÀ1 all through the conversion.
Conclusions
In conclusion, we have demonstrated the first general
À
and facile C Cl bond activation of chloroalkanes in-
cluding dichloromethane and coupling with various
tertiary amines to give quaternary ammonium salts
catalyzed by nickel oxide nanoparticles. The nickel
oxide nanoaprticles were easily recovered and can be
reused at least five times without any loss of catalytic
activity. The reaction provides a useful and problem-
free synthetic route to ionic liquids with diverse sub-
stituents without any difficulty and represents a varia-
tion of the Menshutkin reaction. Current efforts in
our laboratory are directed towards a deeper under-
standing of the mechanism and synthetic applications
of this new type of reaction.
Characterization byX-RayCrystallography
Crystal data for (chloromethyl)triethylammonium chloride
(2a): M=204.13, monoclinic, space group P21/n, a=
11.26(5), b=8.060(5), c=12.515(5) , b=106.527(5)o, V=
1088.5(9) 3, T=293(2) K, Z=4, m=0.551 mmÀ1, 1cald
=
1.246 mgmÀ3, F
(000)=440, no. of data collected: 4229, no.
G
of unique data: 2465, R=0.0678, Rw=0.1937. Crystallo-
graphic data for 2a have been deposited with the Cambridge
Crystallographic Data Centre as supplementary publication
number of CCDC 247262. These data can be obtained free
from the Cambridge Crystallographic Data Centre, 12,
Union Road, Cambridge CB21EZ, UK; fax: (+44)1223–
336–033; or deposit@ddcd.cam.ac.uk].
Experimental Section
General Information
Characterization of New Compounds
Solvents were dried and distilled according to standard
methods before use. Dichloromethane was distilled form
P2O5 under nitrogen. Reagents were purchased from Al-
drich Chemical Co. and Strem Chemical Co. and were used
as received. All yields are based upon isolated material.
1H NMRand 13C NMRspectra were obtained with a Bruker
300 MHz spectrometer. Coupling constants (J values) are re-
ported in Hertz (Hz), and spin multiplicities are indicated
by the following symbols: s (singlet), d (doublet), t (triplet),
q (quartet), m (multiplet). Elemental analyses were done at
the National Center for Inter-University Research Facilities,
Seoul National University. High Resolution Mass Spectra
were obtained at Korea Basic Science Institute (Daegu,
Korea). High-resolution mass spectrometry (HR-MS) data
are reported in the form of m/z (intensity relative to base
peak=100). Diffraction data of (chloromethyl)triethyl am-
monium chloride (2a, [Et3NCH2Cl]+ClÀ) for structure deter-
mination were measured with an Enraf–Nonius CCD single-
crystal X-ray diffractometer at room temperature using
graphite-monochromated Mo Ka radiation (l =0.71013 ).
Preliminary orientation matrixes and unit cell parameters
were obtained from the peaks of the first 10 frames and
then refined using the whole data set. Frames were integrat-
ed and corrected for Lorentz and polarization effects using
DENZO. The structure was solved by direct methods using
SHELXS-97 and refined by full-matrix least-squares fitting
with SHELXL-97. All non-hydrogen atoms were refined
anisotropically, and all hydrogen atoms not involving hydro-
gen bonding were treated as idealized contributions.
[C8H19NCl]+ClÀ (4c): 1H NMR(CDCl 3): d=3.81 (t, J=
6.6 Hz, 1H), 3.53 (t, J=6.3 Hz, 1H), 2.81 (q, J=7.2 Hz,
6H), 1.08 (t, J=7.2 Hz, 9H); 13C NMR(CDCl 3, 75 MHz):
d=54.3, 46.3, 36.4, 9.1; HR-MS: m/z=164.1201, calcd. for
C8H19N1Cl1: 164.1206; anal. calcd. for C8H19NCl: C 58.49, H
11.67, N 8.53; found: C 58.65, H 11.66, N 8.92.
[C9H21NCl]+ClÀ (4d): 1H NMR(CDCl 3): d=3.68 (br,
2H), 3.64 (br, 1H), 3.23 (br, 6H), 3.11 (br, 1H), 2.38 (br,
2H), 1.44 (br, 9H); 13C NMR(CDCl 3, 75 MHz): d=57.7,
49.1, 46.6, 21.1, 9.7; HR-MS: m/z=178.1369, calcd. for
C9H21NCl: 178.1363; anal. calcd. for C9H21N1Cl: C 60.63, H
11.88, N 7.86; found: C 60.45, H 11.53, N 8.11.
[C10H23NCl]+ClÀ (4e): 1H NMR(CDCl 3): d=3.91 (br,
2H), 3.62 (br, 6H), 3.17 (br, 2H), 2.48 (br, 2H), 1.53 (br,
9H), 1.26 (br, 2H); 13C NMR(CDCl 3, 75 MHz): d=55.7,
54.2, 46.7, 43.9, 26.0, 9.3; HR-MS: m/z=192.1519, calcd. for
C10H23NCl: 192.1519; anal. calcd. for C10H23NCl: C 62.45, H
12.06, N 7.29; found: C 62.55, H 12.23, N 7.38.
Acknowledgements
This work was supported by grant No. (R01–2005–000–
10548–0) from the Basic Research Program of the Korea Sci-
ence & Engineering Foundation. J. W. H. is grateful to the re-
search fund of Hanyang University (HY-2003).
Adv. Synth. Catal. 2007, 349, 411 – 416
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
415