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RSC Advances
in a round-bottom ask (25 mL), water (5 mL) was added and 3.79 (d, J ¼ 7.6 Hz, 2H, CH2), 4.95 (t, J ¼ 7.6 Hz, 1H, CH), 6.84–
reaction mixture was stirred at 60 ꢁC in a microwave synthesizer 8.0 (m, 13H, Ar-H), 8.10 (bs, 1H, NH). MS (ESI): 373 (M+).
for 10 min (Table 6). Aer completion of the reaction (moni-
tored by TLC), the reaction mixture was extracted with hot ethyl
Conclusions
acetate (2 ꢂ 5 mL). The organic layer was washed with water and
dried over anhyd. Na2SO4. The product was obtained aer
We have developed a novel catalytic system derived from
removing the solvent under reduced pressure followed by
amorphous carbon/silica composites and ionic liquid for
passing through column of silica gel and elution with
carrying out Knoevenagel condensation, reductive amination
EtOAc : pet. ether (2 : 1).
and Michael addition in water. The catalyst allows reactions to
be carried out in the most benign of reaction media and avoids
most of the problems normally associated with the use of ionic
liquids. The catalyst can be easily recycled without loss of
activity. Simplicity of operation and the environmentally benign
and legislatively robust nature of reaction conditions are the
General procedure for Michael addition of indole to a,b-
unsaturated ketone
To a mixture of indole (1.2 mmol), a,b-unsaturated ketone (1
mmol) in a round-bottom ask (25 mL) and CSC-Star-Glu-IL2
(0.2 g, 12 mol% SO3H), water (7 mL) was added and reaction
mixture was stirred at 100 ꢁC for an appropriate time (Table 7).
main advantages of the developed protocols.
Aer completion of the reaction (monitored by TLC), the reac- Acknowledgements
tion mixture was extracted with hot ethyl acetate (2 ꢂ 5 mL).
We thank the Director, IIIM Jammu for spectral and library
The organic layer was washed with water and dried over anhyd.
facilities; Head, Sophisticated Analytical Instrumentation
Facility, Punjab University Chandigarh for XRD, SEM and TEM;
Na2SO4. Finally, the product was obtained aer removal of the
solvent under reduced pressure followed by passing through
and Head, RSIC, IIT Roorkee for thermal analysis and elemental
column of silica gel and elution with EtOAc : pet. ether (1 : 6).
analysis. Financial support from UGC, New Delhi (Major
The catalyst was dried in a vacuum desiccator for 1 h and
Research Project, F 41-281/2012 (SR)) is gratefully acknowledged.
reused in the next run.
The structures of the products were conrmed by IR, 1H
NMR, mass spectral data and comparison with authentic
samples available commercially or prepared according to the
Notes and references
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OCH3), 4.23–4.47 (q, J ¼ 7 Hz, 2H, CH2CH3), 7.05 (d, J ¼ 7 Hz,
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Ethyl-(E)-2-cyano-3-(20,40-dimethoxyphenyl)prop-2-enoate
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1
(ymax in cmꢀ1, KBr): 3409 (N–H str.), 1602 (C]C str.) H NMR
(CDCl3): d 3.87 (s, 3H, OCH3), 3.94 (bs, 1H, NH), 4.22 (s, 2H,
CH2), 6.55 (d, J ¼ 9.06 Hz, 2H, Ar-H), 6.84 (d, J ¼ 9.06 Hz, 2H, Ar-
H), 7.06 (d, J ¼ 9.06 Hz, 2H, Ar-H), 7.27 (d, J ¼ 8.30 Hz, 2H, Ar-H). 10 (a) B. Tamami and A. Fadavi, Catal. Commun., 2005, 6, 747;
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