RSC Advances
Page 6 of 8
RSC Advances
DOI: 10.1039/C4RA15315D
ARTICLE
3
4
5
6
Succinimideꢀ
Nꢀsulfonic acid
H2O, 70° C
60
87
95
86
95
[29]
[23]
[30]
mmol) in ethanol as solvent. Then the mixture was stirred for the
appropriate time under reflux condition. The progress was monitored
by TLC. After completion of the reaction, the reaction mixture was
cooled to room temperature and the catalyst was separated by an
external magnet. The products were extracted with ethanol, then
EtOH was evaporated under reduced pressure to afford the
essentially pure products. In some cases, the product was
recrystalized from ethanol for further purification.
CuCl2/Fe3O4ꢀ EtOH, reflux 60
TEDETA
NH2SO3H
H2O, 70° C
30
4.2 General procedure for the synthesis of polyhydroquinolines
Fe3O4ꢀSAꢀ
PPCA
EtOH, reflux 30
This
work
A mixture of dimedone (1 mmol), aldehyde (1mmol), ethyl
acetoacetate (1 mmol), ammonium acetate (1.2 mmol) and Fe3O4ꢀ
SAꢀPPCA as catalyst (10 mg, 4.3 × 10ꢀ3 mmol ) in ethanol were stirred
at 50 °C for an appropriate time. The progress of reaction was
monitored by TLC. After completion of the reaction, the catalyst was
separated by an external magnet and solvent was evaporated. The
residue was extracted by ethyl acetate (3×10 mL) and the combined
organic extract was washed with water (3×10 mL), organic layer was
dried over anhydrous sodium sulfate and evaporated to dryness. A
crude solid was obtained. The pure product was obtained through
crystallization from ethanol.
7
8
Yb(OTf)3
MCMꢀ41
EtOH, r.t
120
94
87
[31]
[27]
90° C,
Solvent free
20
9
PdCl2
THF, reflux
H2O, r.t.
270
210
86
72
[32]
[33]
10
LꢀProline
4.3 Representative NMR Data
11
Fe3O4ꢀSAꢀ
PPCA
EtOH, 50° C 110
91
This
work
1H NMR of 2ꢀ(2ꢀhydroxyꢀ4ꢀmethoxyphenyl)ꢀ2,3ꢀdihydroquinazolinꢀ
1
4(1H)ꢀone 3f: Mp: 195ꢀ198; H NMR (400 MHz, DMSO):
δ = 3.65
(s, 3H), 5.96 (s,1H), 6.27ꢀ6.29 (m,1H), 6.38 (s,1H), 6.66ꢀ6.68 (m,
2H), 6.98 (s,1H), 7.13ꢀ7.15 (m, 1H), 7.21ꢀ7.23 (m, 1H), 7.57 (s, 1H),
7.68ꢀ7.69 (d, 1H), 9.35 (s, 1H) ppm.
a
Reaction condition: 4ꢀmethylbenzaldehyde (1mmol) and
anthranilamide (1mmol).
b
1H and 13C NMR of 2ꢀ(4ꢀethoxyphenyl)ꢀ2,3ꢀdihydroquinazolinꢀ
Reaction condition: 4ꢀmethylbenzaldehyde, dimedone, ethyl
1
acetoacetate and NH4OAc.
4(1H)ꢀone 3g: Mp: 171ꢀ173; H NMR (400 MHz, CDCl3):
δ = 1.45
(t, 3H), 4.06 (q, 2H), 5.75 (s, 1H), 5.80ꢀ5.85 (m, 1H), 6.66ꢀ6.68 (m,
1H), 6.90ꢀ6.95 (m, 3H), 7.26 (s,1H), 7.27ꢀ7.34 (m, 1H), 7.50ꢀ7.51
3 Conclusions
(m, 2H), 7.95 (s,1H); 13C NMR (100 MHz, CDCl3):
δ = 15.9, 64.7,
In this study Fe3O4ꢀSAꢀPPCA nanocomposite was synthesized for
the first time on a novel oneꢀpot reflux route as a new heterogeneous
catalyst. The catalytic activity of Fe3O4ꢀSA–PPCA was probed
through oneꢀpot synthesis of 2,3ꢀdihydroquinazolinꢀ4(1H)ꢀones and
polyhydroquinoline compounds. The heterogeneous catalyst showed
very high conversion rates and could be recovered easily and reused
many times without significant loss of its catalytic activity, which
makes it useful and attractive for synthesis of these classes of
compounds for economic availability and greater selectivity.
69.8, 115.6, 116, 116.7, 120.7, 129.7, 129.8, 131.5, 135, 135.1,
148.6, 166.9 ppm.
1H and 13C NMR of Ethyl 4ꢀ(4ꢀethoxyphenyl)ꢀ2,7,7ꢀtrimethylꢀ5ꢀ
oxoꢀ1,4,5,6,7,8ꢀhexahydroquinolineꢀ3ꢀcarboxylate 4f: Mp: 179ꢀ181;
1H NMR (400 MHz, CDCl3):
δ = 0.95 (s, 3H), 1.07 (s, 3H), 1.20ꢀ
1.21 (m, 3H), 1.37ꢀ1.38 (m, 3H), 2.15ꢀ2.38 (m, 7H), 3.96 (t, 2H),
4.06 (t, 2H), 4.99 (s, 1H), 5.80 (s, 1H), 6.73 (d, J = 6.4 Hz, 2H), 7.19
(d, J = 6.4 Hz, 2H); 13C NMR (100 MHz, CDCl3):
δ = 15.4, 16.05,
20.3, 28.2, 30.6, 33,7, 36.8, 41,8, 51.9, 60.9, 64.3, 107.3, 113.1,
114.9, 130.1, 140.7, 144.7, 150.2, 158.3, 169, 198 ppm. Anal. Calcd.
for C23H29NO4:C, 72.04; H, 7.62; N, 3.65; Found: C, 72.13; H, 6.31;
N, 3.74.
4 Experimental
4.1. Materials and instruments
The reagents and solvents used in this work were all purchased from
Aldrich and Merck and used without further purification. FTꢀIR Acknowledgements
measurements were performed using KBr disc using a NICOLET
impact 410 spectrometer. The known products were characterized by This work was supported by the research facilities of Ilam
comparison of their spectral (1HꢀNMR, and 13CꢀNMR, Bruker University, Ilam, Iran.
NMRꢀSpectrometer FX 400Q) and physical data with those of
authentic samples. Powder XRD was collected with a RigakuꢀDmax
2500 diffractometer with nickel filtered Cu Ka radiation (λ = 1.5418
2. C. Burda, X. B. Chen, R. B. Narayanan, M. A. ElꢀSayed, Chem. Rev.
A˚, 40 kV). TEM of the NPs were recorded using a ZeissꢀEM10C
TEM. Supermagnetic properties of catalyst was measured on
References
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Vibrating Sample Magnetometer (VSM) MDKFD.
4.1 General procedure for preparation of 2,3-dihydroquinazolin- 5. A. S. K. Hashmi, G. J. Hutchings, Angew. Chem. Int. Ed. 2006, 45, 7896.
4(1H)-ones
6. R. M. Cornell, U. Schwertmann, The Iron Oxides: Structure, Properties,
Reactions Occurrence and Uses, VCH, New York, 1996.
The Fe3O4ꢀSAꢀPPCA (15 mg, 6.7 × 10ꢀ3 mmol) was added to a
mixture of anthranilamide (1 mmol, 0.136 gr) and aldehyde (1
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