Synthesis of bis(substituted benzylidene)cycloalkanone using supported reagents and microwave irradiation

Article abstract of DOI:10.1081/SCC-120004261

Condensation of cycloalkanone with aromatic aldehyde and furfural using supported reagents to prepare bis(substituted benzylidene or furfurylidene)cycloalkanone in excellent yields under microwave irradiation.

Full text of DOI:10.1081/SCC-120004261

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SYNTHESIS OF BIS(SUBSTITUTED
BENZYLIDENE)CYCLOALKANONE USING SUPPORTED
REAGENTS AND MICROWAVE IRRADIATION
Jin-Xian Wang a , Liqin Kang a , Yulai Hu a & Bangguo guo Wei a
a Institute of Chemistry, Department of Chemistry, Northwest Normal University, 95 An Ning
Road (E.), Lanzhou, 730070, China
Published online: 16 Aug 2006.
To cite this article: Jin-Xian Wang , Liqin Kang , Yulai Hu & Bangguo guo Wei (2002): SYNTHESIS OF BIS(SUBSTITUTED
BENZYLIDENE)CYCLOALKANONE USING SUPPORTED REAGENTS AND MICROWAVE IRRADIATION, Synthetic Communications: An
International Journal for Rapid Communication of Synthetic Organic Chemistry, 32:11, 1691-1696
To link to this article: http://dx.doi.org/10.1081/SCC-120004261
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SYNTHETIC COMMUNICATIONS, 32(11), 1691–1696 (2002)
SYNTHESIS OF BIS(SUBSTITUTED
BENZYLIDENE)CYCLOALKANONE
USING SUPPORTED REAGENTS AND
MICROWAVE IRRADIATION
*
Jin-Xian Wang, Liqin Kang, Yulai Hu, and
Bangguo guo Wei
Institute of Chemistry, Department of Chemistry,
Northwest Normal University, 95 An Ning Road (E.),
Lanzhou 730070, China
ABSTRACT
Condensation of cycloalkanone with aromatic aldehyde and
furfural using supported reagents to prepare bis(substituted
benzylidene or furfurylidene)cycloalkanone in excellent
yields under microwave irradiation.
Potassium fluoride has been used widely as a kind of base supported
reagent in organic synthesis.[1–3] Yamawaki and Ando found KF–Celite
could catalyze an alkylating reaction in 1979.[4] Further, they found Al2O3
was the most efficient one to enhance reactivity of KF among common solid
supports, such as silica gel, montmorillonite and clay.[5,6] Moreover,
Yamawaki et al. were the first to use KF–Al2O3 in Knoevenagel condensation
under conventional conditions.[7] However, many of the reaction needed a
*Corresponding author.
1691
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WANG ET AL.
Scheme 1.
long time and gave a low yield. Microwave irradiation has found a lot of
applications in recent years.[8–12] The reaction time can be shortened greatly
under microwave irradiation, so it is a new and convenient synthetic method.
In this paper, we wish to report a very simple and convenient synthesis
of bis(substituted benzylidene or furfurylidene)cycloalkanone by condensa-
tion cycloalkanone with aromatic aldehyde or furfural using KF–Al2O3 as
an inorganic support under microwave irradiation conditions. The combi-
nation of microwave irradiation and supported reagents has been high-
lighted in recent years. The main advantages of the approach are shorter
reaction time, minimum waste, high yields and the experimental ease of
manipulation. Recovery of inorganic/catalyst is generally possible. Here,
we found the condensation reaction of aromatic aldehyde and cycloalka-
none needs only 5 min. The yields of the products are good. The reactions
are shown in Scheme 1 and the results are summarized in Table 1.
RESULTS AND DISCUSSION
Taking the reaction of benzaldehyde with cyclopentanone as an
example, we investigate the effect of the supported reagents on the reaction.
It was found that the activities of supported reagents are in the follow-
ing sequence, respectively: KF–Al2O3>KF>K2CO3–Na2CO3>K2CO3>
Na2CO3. The results are summarized in Table 2.
We have also studied the effect of the power and time of microwave
irradiation on the reaction. The results are summarized in Tables 3 and 4.
We also found that the reaction cannot be carried out if aliphatic
aldehyde is used. To testify the selectivity of the reaction, we carried out
the reaction in ratio (aromatic aldehyde/cycloalkanone) of 2 : 1 and 1 : 1.

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BIS(SUBSTITUTED BENZYLIDENE)CYCLOALKANONE
1693
Table 1. Condensation Products of Cycloalkanone with Aromatic Aldehyde or
Furfural Under Microwave Irradiationa,b,c
No.
R
H
Ketone
Product
Yield (%)
73
3a
3b
3c
3d
3e
3f
H
H
83
80
73
76
80
81
80
82
0
p-OCH3
p-OCH3
p-Cl
3g
3h
3i
p-Cl
3j
CH3(CH2)5CHO
CH3(CH2)3CHO
no reaction
no reaction
3k
0
aIrradiation condition: power 750 W, time 5 min; KF–Al2O3 used as supported
reagent.
bmole ratio: aldehyde : 7cycloalkanone ¼ 2 : 1.
cIsolated yield.

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1694
WANG ET AL.
Table 2. Effect of the Supported Reagent on the Reactiona
Supported Reagent
Yieldb (%)
KF–Al2O3
80
KF
75
K2CO3–Na2CO3
73
K2CO3
54
Na2CO3
0
aIrradiation condition: T ¼ 5 min, P ¼ 750 W.
bIsolated yield.
Table 3. Effect of the Power of MWI on the Reactiona,b
Power (W)
300
0
375
65
600
78
750
80
Yieldc (%)
aIrradiation time: 5 min.
bKF–Al2O3 used as catalyst.
cIsolated yield.
Table 4. Effect of the Time of MWI on the Reactiona,b
Time (min)
Yieldc (%)
2
0
3
5
7
8
74
80
75
68
aIrradiation power: 750 W.
bKF–Al2O3 used as catalyst.
cIsolated yield.
Both the reaction provide the same product ꢀ,ꢀ0-bis(substituted
benzylidene)cycloalkanone. ꢀ-mono(substituted benzylidene)cycloalkanone
was not obtained.
EXPERIMENTAL
Microwave irradiation was carried out with a commertial microwave
oven Glanz WP 750 B at 2450 Hz. IR spectra were measured for KBr discs
using an Alpha Centauri FI-IR spectrophotometer. 1H NMR spectra
(80 MHz) were recorded in CDCl3 using a PT-80 spectrometer or DRX-
200. Spectrometer using tetramethylsilane as internal standard. Chemical
shifts were expressed in ppm. Mass spectra were obtained on a Nippon

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BIS(SUBSTITUTED BENZYLIDENE)CYCLOALKANONE
1695
Schimadzu QP-1000 GC-MS spectrometer. Melting points were determined
with an electrothermal micromelting point apparatus and are uncorrected.
GENERAL PROCEDURE
KF–Al2O3 (0.8 mmol) was added to a mixture of cycloalkanone
(8 mmol) and aromatic aldehyde or furfural (16 mmol). The mixture was
stirred and subjected to microwave irradiation in 750 W for 5 min. After
the completion of the reaction, the mixture was filtered and washed with
acetone immediately till the catalyst was white. Then the acetone was
removed by evaporation. The pure sole product was obtained by recrystal-
lization from ethanol or isolated by a short silica gel column using
petroleum leve: ethyl acetate (10 : 1, v/v) as an eluent.
3a: M.p. 190–191ꢀC (lit.,[13] 189ꢀC), IR ꢁ (KBr): 3058, 3018, 1685,
1567, 1488, 930, 764, 687. 1H NMR (80 MHz, CDCl3): 3.12 (s, 4H),
7.6–7.01 (m, 12H). MS (m/e): 260 (Mþ).
3b: M.p. 118–118.5ꢀC (lit.,[14] 118ꢀC), IR ꢁ (KBr): 3078, 3023, 1660,
1
1572, 1485, 970, 771, 694. H NMR (80 MHz, CDCl3): 1.93–1.70 (m, 2H),
3.01–0.85 (m, 4H), 7.79 (s, 2H), 7.44–7.24 (m, 10H). MS (m/e): 274 (Mþ).
3c: M.p. 170ꢀC (lit.,[15] 172–175ꢀC), IR ꢁ (KBr): 3035, 2963, 2907,
1
1714, 1613, 765. H NMR (200 MHz, CDCl3): 1.97 (m, 2H), 3.02 (m, 2H),
7.57–7.24 (m, 8H). MS (m/e): 184 (Mþ).
3d: M.p. 214–215ꢀC (lit.,[16] 212ꢀC), IR ꢁ (KBr): 3030, 1666, 1596, 996.
1H NMR (80 MHz, CDCl3): 3.10 (s, 4H), 3.81 (s, 6H), 6.90 (d, 4H), 7.43 (d,
4H), 7.69 (s, 2H). MS (m/e): 320 (Mþ).
3e: M.p. 161–162ꢀC (lit.,[17] 162ꢀC), IR ꢁ (KBr): 3005, 1658, 1593, 1558,
1480, 966. 1H NMR (80 MHz, CDCl3): 1.95–0.70 (m, 2H), 2.91 (t, 4H), 3.85
(s, 6H), 6.92 (d, 4H), 7.44 (d, 4H), 7.75 (s, 2H). MS (m/e): 334 (Mþ).
3f: M.p. 224–226ꢀC (lit.,[14] 225–226ꢀC), IR ꢁ (KBr): 3070, 1694, 1584,
1488, 983, 726, 685. 1H NMR (200 MHz, CDCl3): 3.091 (s, 4H), 7.628–7.263
(10H). MS (m/e): 225 (M-35).
3g: M.p. 146–147ꢀC (lit.,[18] 145–147ꢀC), IR ꢁ (KBr): 3050, 1690, 1583,
1
1488, 981. H NMR (200 MHz, CDCl3): 1.99–1.73 (s, 2H), 3.06 (s, 4H),
7.63–2.64 (m, 10H). MS (m/e): 307 (M-35).
3h: M.p. 164–165ꢀC (lit.,[19] 164ꢀC), IR ꢁ (KBr): 3135, 1681, 1625,
1600, 753. 1H NMR (200 MHz, CDCl3): 3.142 (s, 4H), 7.742–6.493 (m,
8H). MS (m/e): 240 (Mþ).
3i: M.p. 143–144ꢀC (lit.,[19] 145ꢀC), IR ꢁ (KBr): 3149, 1679, 1591,
1
1540, 751. H NMR (200 MHz, CDCl3): 1.93–1.71 (s, 2H), 3.08 (s, 4H),
7.78–6.42 (m, 8H). MS (m/e): 254 (Mþ).

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WANG ET AL.
ACKNOWLEDGEMENT
This work was supported by the National Natural Science Foundation
of China and the Northwest Normal University Science and Technology
Development Foundation of China.
REFERENCES
1. Jones, G. Organic Reaction; Wiley, New York, 1967, 15, 204.
2. Lehnert, W. Tetrahedron Letts. 1970, 54, 4723.
3. Rao, P.S.; Venkataratnam, R.V. Tetrahedron Letts. 1991, 32, 5821.
4. Ando, T.; Yamawaki J. Chem. Lett. 1979, 45.
5. Yamawaki, J.; Ando, T. Chem. Lett. 1979, 755.
6. Ando, T.; Yamawali, J.; Kawate, T.; Sumi, S. Bull. Chem. Soc. Jpn.
1982, 55, 2504.
7. Yamawaki, J.; Kawate, T.; Ando, T.; Hanafusa, T. Bull. Chem. Soc.
Jpn. 1983, 56, 1885.
8. Gedye, R.N.; Smith, F.; Westaway, K.; Ali, H.; Baldisern, L.; Laberge,
L.; Rousell, J. Tetrahedron Lett. 1986, 27, 2792.
9. Gedye, R.N.; Smith, F.E.; Westway, K.C. Can. J. Chem. 1988, 66, 17.
10. Georges, B.; Mustapha, M.A. Tetrahedron. 1990, 46, 5167.
11. Didier, V.; Mekki, L.; Abdelkrim, B.A. Chem. Ind. (London) 1991,
5, 176.
12. Didier, V.; Abdelkrim, B.A. Synth. Commun. 1991, 21, 63.
13. Bellstein’s Handbuch der Org. Chem. 7, 513.
14. Bellstein’s Handbuch der Org. Chem. 7, 514.
15. Bellstein’s Handbuch der Org. Chem. 7, 403.
16. Ibid. 8, 359.
17. Bellstein’s Handbuch der Org. Chem. 8, II, 413.
18. Bellstein’s Handbuch der Org. Chem. 7, 515.
19. (a) Leonard, N.J.; Miller, L.A.; Berry, J.W. J. Am. Chem. Soc. 1957,
79, 1482; (b) Alexander, K.; Hafner, L.S.; Smith, G.H.; Schniepp, L.E.
J. Am. Chem. Soc. 1950, 72, 5506.
Received in the Netherlands May 17, 2001