A facile synthesis of flavones catalysed by gallium(III) triflate

Article abstract of DOI:10.3184/030823409X396409

Ga(OTf)₃ was explored as a novel catalyst for the cyclisation of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones in nitromethane to flavones with excellent yields.

Full text of DOI:10.3184/030823409X396409

JOURNAL OF CHEMICAL RESEARCH 2009
JANUARY, 27–29
RESEARCH PAPER 27
A facile synthesis of flavones catalysed by gallium(III) triflate
a
b
b
b
a,b*
Can Jin , Fei He , Huayue Wu , Jiuxi Chen and Weike Su
a
Key Laboratory of Pharmaceutical Engineering of Ministry of Education, College of Pharmaceutical Sciences,
Zhejiang University of Technology, Hangzhou 310014, P.R. China
bCollege of Chemistry and Materials Science, Wenzhou University, Wenzhou 325027, P.R. China
Ga(OTf)3 was explored as a novel catalyst for the cyclisation of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones in
nitromethane to flavones with excellent yields.
Keywords: JDOOLXPꢀ,,,ꢁꢂWULÀDWHꢃꢂÀDYRQHVꢃꢂF\FOLVDWLRQꢂUHDFWLRQ
7
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Table
1 Synthesis of flavones under different reaction
1,2
conditionsa
natural products. They are an integral part of the human
diet and possess a wide range of biological activities, such as
3
4
5
anticancer, antibacterial, anti-AIDS agents.
OH
O
O
cat.
0
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solvent
or 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones, which are
prepared from acylation of an o-hydroxyacetophenone with an
aromatic acid chloride yielding an aryl ester. The ester is then
rearranged by a base (pyridine/KOH) to 1-(2-hydroxyphenyl)-
O
O
Entry
Solvent
Catalyst
Loading/
mol%
Yields/%b
6,7
3
-aryl-1,3-propanediones. The cyclisation reaction of 1-(2-
1
2
CH3NO2
CH3NO2
CH NO
Cu(OTf)2
Mg(OTf)2
Bi(OTf)3
Yb(OTf)3
Zn(OTf)2
Y(OTf)3
1
1
75
47
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8
,9
with different catalysts such as H SO /AcOH, NaHSO /
2
4
4
3
1
83
3
3
2
2
1
0
11
12
13
SiO , Mo/W complexes, I -DMSO, Co(III), supported
4
CH NO
1
87
2
2
1
4
15
WULÀXRURPHWKDQHVXOIRQLFꢂDFLG and CuCl .
5
CH3NO2
CH3NO2
CH3NO2
CH3NO2
CH3NO2
CH NO
1
70
2
6
1
89
Although a variety of catalysts have been introduced for the
V\QWKHVLVꢂRIꢂÀDYRQHVꢃꢂPDQ\ꢂRIꢂWKHVHꢂPHWKRGVꢂDUHꢂDVVRFLDWHGꢂ
with one or more disadvantages such as relatively long
reaction time, environmentally unfriendly catalyst, low yield,
requirement of excess reagents or catalysts and harsh reaction
conditions. Therefore, the development of environmentally
benign, high-yielding and clean approaches for the synthesis
RIꢂÀDYRQHVꢂVWLOOꢂUHPDLQVꢂDQꢂDFWLYHꢂUHVHDUFKꢂDUHDꢄ
7
Ca(OTf)2
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
Ga(OTf)3
CuCl2
1
48
8
0.5
5
95
9
97
10
11
3
2
2.5
1
96
CH3NO2
CH3NO2
CH3CH2OH
CH3CN
CH2Cl2
96
1
1
1
1
1
2
3
4
5
6
10
1
97
81
1
88
1
72
0HWDOꢂ WULÀDWHVꢂ DUHꢂ FXUUHQWO\ꢂ RIꢂ JUHDWꢂ LQWHUHVWꢂ DQGꢂ EHFDXVHꢂ
H2O
1
10
of their unique catalysis, they were widely used in organic
synthesis. Recently, we have reported some organic reactions
17
18
CH NO
1
33 (57)c
5
3
2
CH3NO2
none
–
16-18
a80°C for 2 hour. bIsolated yield. cIn the presence of 40 mol%
CuCl2.
XVLQJꢂ PHWDOꢂ WULÀDWHVꢄ
To the best of our knowledge,
the Ga(OTf) ꢆSURPRWHGꢂ V\QWKHVLVꢂ RIꢂ ÀDYRQHVꢂ KDVꢂ QRWꢂ EHHQꢂ
3
reported. In continuation of our interest in Lewis acids
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amounts of Ga(OTf) , 1 mol% of Ga(OTf) was enough and
3
3
excess catalyst did not noticeably increase the yield (Table 1,
entries 8–12). As a result, we obtained the following optimised
Ga(OTf) as a catalyst under mild conditions.
3
conditions: with 1 mol% Ga(OTf) at 80°C for 2 hours with
We have investigated a variety of reaction conditions with
the cyclisation reaction of 1-(2-hydroxyphenyl)-3-aryl-1,3-
propanedione in the present of various Lewis acids. The
results are summarised in Table 1. It seems that nitromethane
is a much better solvent (Table 1, entry 11, yield 97%) than
the other solvents which were tested such as ethanol (Table 1,
entry 13, yield 81%), acetonitrile (Table 1, entry 14, yield
3
nitromethane as the solvent.
With optimal conditions in hand, the cyclisation of different
-(2-hydroxyphenyl)-3-aryl-1,3-propanediones was examined
1
to explore the scope of the reaction (Table 2). It is worth
mentioning that the cyclisation of 1-(2-hydroxyphenyl)-3-
aryl-1,3-propanediones containing a nitro group provides
the desired product in moderate yield in CH3NO2 due to
poor solubility (Table 2, entries 6, 13, 18 and 19). Therefore,
the reactions was run in 1,2-dichloroethane so as to ensure
good yield.
8
8%), dichloromethane (Table 1, entry 15, yield 72%) and
water (Table 1, entry 16, yield 10%). The best results were
obtained by carrying out the reaction at 80°C for 2 hours in the
presence of a catalytic amount of Ga(OTf) with nitromethane
as the solvent. In contrast, the product was obtained in low
3
From the results shown in Table 2, it can be seen that most
of the reactions proceeded smoothly with excellent yields.
Further studies indicated electron-withdrawing and electron-
donating groups on the aromatic ring did not affect the
UHDFWLRQꢂVLJQL¿FDQWO\ꢂHLWKHUꢂLQꢂWKHꢂ\LHOGꢂRIꢂSURGXFWꢂRUꢂWKHꢂUDWHꢂ
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were obtained with high selectivity, practically without by-
products and starting materials.
\
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exception of Mg(OTf) and Ca(OTf) examined showed good
2
2
catalytic effects. However, Ga(OTf) was particularly effective
3
for this reaction with the 96% yields of corresponding product.
In contrast, other Lewis acid such as CuCl (Table 1, entry 17)
2
JDYHꢂORZꢂ\LHOGVꢂꢀꢇꢇꢉꢁꢄꢂ$GGLWLRQDOO\ꢃꢂZHꢂDOVRꢂVWXGLHGꢂLQÀXHQFHꢂ
of the amount of Ga(OTf) on the reaction yields. It was
3
found that the yield was not obviously affected with different
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Compared to previous reported methodologies, important
*
Correspondent. E-mail: suweike@zjut.edu.cn

2
8
JOURNAL OF CHEMICAL RESEARCH 2009
Table 2 Ga(OTf)3 catalysed synthesis of flavonesa
R4
R
5
R1
R1
R2
R3
OH R4
R5
R2
R3
O
O
Ga(OTf) (1mol%)
3
CH NO
3
2
O
O
Entry
R1
R2
R3
R4
R5
Product
Time/h
Yield/%b
1
2
3
4
5
6
7
8
9
H
H
H
H
H
H
H
Br
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Cl
H
H
H
Cl
H
H
H
H
H
H
H
H
H
H
H
H
H
Cl
Cl
1a
1b
1c
1d
1e
2
96
92
91
97
95
89
91
90
95
93
94
95
87
94
93
92
95
87
93
2.5
3
H
H
H
H
OCH3
CH3
NO2
H
2
H
H
2
c
H
H
1f
4
H
H
1g
1h
1i
1j
1k
1l
2.5
4
H
Br
Cl
CH3
H
H
Cl
2.5
3.5
2
10
11
12
13
14
15
16
17
18
19
Cl
Cl
H
CH3
CH3
CH3
CH3
H
Cl
H
H
2
c
H
NO2
CH3
H
1m
1n
1o
1p
1q
4
H
2
CH3
H
2
Cl
CH3
OCH3
H
2
H
OCH3
NO2
OCH3
c
1.5
4
c
H
1r
c
H
NO2
1s
4
aReaction temperature: 80°C. bIsolated yield. 1.2-dichloroethane was used as solvent.
features of present protocol include simple work-up, a shorter
reaction time, the use of environmentally benign, recoverable
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Currently, studies on the extension of this protocol are ongoing
in our laboratory.
2-(2,4-dichlorophenyl)-4H-chromen-4-one (1c): White solid: m.p.
21 1
1
72–175°C (Lit. 172–174°C); H NMR (400 MHz, CDCl ): G 8.25
3
(
d, J = 8.0 Hz, 1H, ArH), 7.70–7.74 (m, 1H, ArH), 7.60–7.61 (m, 2H,
ArH), 7.51 (d, J = 8.0 Hz, 1H, ArH), 7.40–7.46 (m, 2H, ArH), 6.66
13
(
s, 1H, CH). C NMR (100 MHz, CDCl ): G 177.93, 161.42, 156.47,
3
1
1
8
6
37.36, 134.00, 133.74, 131.37, 130.70, 130.33, 127.53, 125.75,
25.44, 123.78, 118.12, 113.13. IR (KBr): 1650, 1467, 1381, 1365,
+
+
23, 775, 753. MS (EI): m/z (%) = 290 (100) [M ], 292 (M + 2,
Experimental
0),264 (20), 262 (35), 255 (70), 120 (73), 92 (35)
&
KHPLFDOVꢂDQGꢂVROYHQWVꢂZHUHꢂHLWKHUꢂSXUFKDVHGꢂRUꢂSXUL¿HGꢂE\ꢂVWDQGDUGꢂ
2
-(4-methoxyphenyl)-4H-chromen-4-one (1d): White solid:
techniques. Melting points were recorded on Digital Melting Point
Apparatus WRS-1B and are uncorrected. IR spectra were recorded
on an AVATAR 370 FI-IR spectrophotometer. Mass spectra (EI)
were measured with Thermo Finnigan LCQ-Advantage or Finnigan
19
1
m.p. 157–159°C (Lit. 157–158°C); H NMR (400 MHz, CDCl ):
3
G 8.21 (d, J = 8.0 Hz, 1H,ArH), 7.85 (d, J = 8.4 Hz, 2H,ArH), 7.65–7.69
(
m, 1H, ArH), 7.53 (d, J = 8.0 Hz, 1H, ArH), 7.40 (t, J = 7.2 Hz, 1H,
13
ArH), 6.98–7.01 (m, 2H, ArH), 6.72 (s, 1H, CH), 3.87(s, 3H, CH ).
C
3
1
13
Trace DSQ. H NMR and C NMR spectra were recorded on a
NMR (100 MHz, CDCl ): G 178.22, 163.25, 162.28, 156.03, 133.45,
3
Varian Mercury plus-400 instrument using CDCl as the solvent with
3
127.86, 125.50, 124.95, 123.80, 120.08, 117.86, 114.33, 106.01, 55.39.
tetramethylsilane (TMS) as an internal standard at room temperature.
Chemical shifts are given in G units relative to TMS, the coupling
constants J are given in Hz. Elemental analysis was performed on a
VarioEL-III instrument.
–1
IR (KBr): 1649, 1608, 1465, 1380, 1133, 827, 767 cm . MS (EI): m/z
+
(
%) = 252 (100) [M ], 237(7), 221(15), 209(13), 132(63).
2
-p-tolyl-4H-chromen-4-one (1e): Yellow solid: m.p. 108–111°C
21 1
(
Lit. 108–111°C); H NMR (400 MHz, CDCl ): G 8.21 (d, J = 8.0 Hz,
3
1
H, ArH), 7.78 (s, 2H, ArH), 7.65 (t, J = 4.0 Hz, 1H, ArH), 7.52 (s,
H, ArH), 7.27 (s, 1H, ArH), 7.38 (t, J = 8 Hz, 2H, ArH), 6.76 (s,
7
\SLFDOꢀSURFHGXUHꢀIRUꢀV\QWKHVLVꢀRIꢀÀDYRQHV
1
Ga(OTf) (24.5 mg, 0.05 mmol, 1 mol%) was added to a solution
13
3
1H, CH), 2.40 (s, 3H, CH ). C NMR (100 MHz, CDCl ): G 178.26,
3
3
of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanedione (5 mmol) in
1
63.37, 156.05, 142.10, 133.49, 129.61, 128.73, 126.04, 125.49,
CH NO (20 ml). The mixture was stirred at 80°C for 2–4 hours.
3
2
124.96, 123.83, 117.92, 106.76, 21.38. IR (KBr): 1637, 1465, 1371,
After completion of the reaction, as indicated by TLC, water was
+
1
1
227, 817, 752, 634. MS (EI): m/z (%) = 236 (100) [M ], 221 (44),
added, and the product was extracted with diethyl ether (3 u 10 ml).
20 (36), 115 (37), 104 (10), 92 (23).
The organic layer was dried ( MgSO ) and evaporated and the crude
4
2-(4-nitrophenyl)-4H-chromen-4-one (1f): Yellow solid: m.p. 241–
SURGXFWꢂZDVꢂSXUL¿HGꢂE\ꢂÀDVKꢂFROXPQꢂFKURPDWRJUDSK\ꢂWRꢂSURYLGHꢂWKHꢂ
22
1
2
43°C (Lit. 242–244°C); H NMR (400 MHz, CDCl ): G 8.11–
3
corresponding product.
8.40 (m, 5H, ArH), 7.48–7.76 (m, 3H, ArH), 6.92 (s, 1H, CH). 13C
19
2
-phenyl-4H-chromene (1a): White solid: m.p. 96–97°C (Lit.
NMR (100 MHz, CDCl ): G 177.93, 160.56, 156.18, 149.46, 137.66,
3
1
9
6–97°C); H NMR (400 MHz, CDCl ): G 8.24 (d, J = 8.0 Hz, 1H,
134.31, 127.21, 125.88, 125.75, 124.23, 123.96, 118.19, 108.64. IR
3
ArH), 7.94 (d, J = 8.0 Hz, 2H, ArH), 7.71 (t, J = 8.0 Hz, 1H, ArH),
.53–7.60 (m, 4H, ArH), 7.43 (t, J = 8.0 Hz, 1H, ArH), 6.86 (s, 1H,
(KBr): 1659, 1520, 1467, 1346, 1130, 857, 750, 692. MS (EI): m/z
7
(%) = 267 (25) [M+], 236 (100), 208 (25), 166 (9), 115 (13), 92 (12).
1
3
CH). C NMR (100 MHz, CDCl ): G 163.33, 156.29, 133.77, 131.75,
2-(2-chlorophenyl)-4H-chromen-4-one (1g): Yellow solid: m.p.
3
1
31.59, 129.03, 126.27, 125.68, 125.21, 120.11, 118.17, 107.64. IR
193–195°C (Lit.22 192–193°C); 1H NMR (400 MHz, CDCl ): G 8.26
3
–1
(
KBr): 1646, 1605, 1568, 1128, 768 cm . MS (EI): m/z (%) = 222
(d, J = 8.0 Hz, 1H, ArH), 7.62–7.71 (m, 2H, ArH), 7.39–7.53 (m,
+
13
(100) [M ], 194 (60), 165 (9), 120 (55), 92(43).
5H, ArH), 6.67 (s, 1H, CH). C NMR (100 MHz, CDCl ): G 177.96,
3
2
-(4-chlorophenyl)-4H-chromen-4-one (1b): White solid: m.p. 185–
162.47, 156.50, 133.81, 132.75, 131.69, 130.69, 130.52, 127.00,
20
1
1
87°C (Lit. 185–188°C); H NMR (400 MHz, CDCl ): G 8.21 (d,
125.60, 125.22, 123.72, 118.09, 112.89. IR (KBr): 1651, 1368, 1153,
3
+
+
J = 8.0 Hz, 1H, ArH), 7.84 (d, J = 8.0 Hz, 2H, ArH), 7.70 (t, J = 8.0 Hz,
1066, 909, 767. MS (EI): m/z (%) = 256 (100) [M ], 258 (M + 2,
34), 228 (39), 221 (42), 165 (13), 120 (63), 92 (47).
1
H, ArH), 7.54 (d, J = 8.0 Hz, 1H, ArH), 7.48 (d, J = 8.0 Hz, 2H, ArH),
13
7
.42 (t, J = 8.0 Hz, 1H, ArH), 6.78 (s, 1H, CH). C NMR (100 MHz,
6,8-dibromo-2-(4-chlorophenyl)-4H-chromen-4-one (1h): Yellow
23
1
CDCl ): G 178.08, 162.09, 156.06, 137.79, 133.81, 130.15, 129.29,
solid: m.p. 248–251°C (Lit. 249–250°C); H NMR (400 MHz,
3
1
1
3
27.47, 125.65, 125.27, 123.84, 117.95, 107.60. IR (KBr): 1641, 1466,
CDCl ): G 8.29 (s, 1H, ArH), 8.04 (s, 1H, ArH), 7.93 (d, J = 8.0
3
–1
+
+
13
090, 828, 772 cm . MS (EI): m/z (%) = 256 (100) [M ], 258 (M + 2,
Hz, 2H, ArH), 7.53 (d, J = 8.0 Hz, 2H, ArH), 6.84 (s, 1H, CH).
C
6), 230 (14), 228 (46), 221 (15), 120 (67), 92 (32).
NMR (100 MHz, CDCl ): G 176.21, 162.51, 151.74, 139.47, 138.63,
3

JOURNAL OF CHEMICAL RESEARCH 2009 29
1
1
29.63, 129.41, 127.89, 127.74, 126.00, 118.73, 118.11, 113.03,
07.29. IR (KBr): 1649, 1612, 1492, 1092, 839, 699. MS (EI):
solid: m.p. 196.1–196.2°C (lit.25 194–195°C). H NMR (400 MHz,
1
CDCl ), G 7.88 (d, J = 8.0 Hz, 2H, ArH), 7.61 (d, J = 4.0 Hz, 1H,
3
+
+
m/z (%) = 414 (100) [M ], 416 (M + 2, 74), 278 (98), 250 (11), 197
ArH), 7.45 (d, J = 8.0 Hz, 1H, ArH), 7.29 (d, J = 4.0 Hz, 1H, ArH),
(16), 163 (10), 136 (15).
7.03 (d, J = 8.0 Hz, 2H, ArH), 6.76 (s, 1H, CH), 3.92 (s, 3H, OCH ),
3
13
2
-(4-chlorophenyl)-7-methyl-4H-chromen-4-one (1i): Yellow
3.90 (s, 3H, OCH ). C NMR (100 MHz, CDCl ), G 178.30, 163.28,
3
3
1
solid: m.p. 179–180°C; H NMR (400 MHz, CDCl ): G 8.05 (d,
162.36, 156.95, 151.04, 127.97, 124.54, 124.16, 123.59, 119.39,
114.47, 105.52, 104.91, 55.96, 55.51. IR (KBr): 1649, 1608, 1515,
1466, 1382, 1268, 1195, 1026, 827, 768. MS (EI): m/z (%) = 282
3
J = 8.0 Hz, 1H, ArH), 7.77–7.80 (m, 2H, ArH), 7.43–7.46 (m, 2H,
ArH), 7.29 (s, 1H, ArH), 7.19 (d, J = 8.0 Hz, 1H, ArH), 6.70 (s, 1H,
13
+
ArH), 2.47 (s, 3H, CH ). C NMR (100 MHz, CDCl ): G 177.89,
(100) [M ], 272 (35), 252 (24), 150 (96), 132 (24), 107 (29).
3
3
1
1
1
61.60, 156.05, 145.11, 137.55, 130.11, 129.14, 127.24, 126.66,
6-nitro-2-phenyl-4H-chromen-4-one (1r): Pale yellow solid:
25.25, 121.46, 117.63, 107.36, 21.69. IR (KBr): 1638, 1490, 1410,
m.p. 194.6–195.1°C. 1H NMR (400 MHz, CDCl ), G 9.12 (s, 1H,
3
+
092, 906, 827, 813. 477. MS (EI): m/z (%) = 270 (5) [M ], 242
ArH), 8.52 (d, J = 8.0 Hz, 1H, ArH), 7.93–7.95 (m, 2H, ArH), 7.74 (d,
(
100), 178 (90), 152 (70), 78 (6). Anal. Calcd for C H ClO : C,
13
1
6
11
2
J = 4.0 Hz, 1H, ArH), 7.55–7.63 (m, 3H, ArH), 6.90 (s, 1H, CH). C
7
0.99; H, 4.10; Found: C, 70.97; H, 4.15%.
NMR (100 MHz, CDCl ), G 176.67, 164.15, 159.08, 144.86, 132.39,
3
6
-chloro-2-(4-chlorophenyl)-4H-chromen-4-one (1j): White solid:
1
30.78, 129.30, 128.15, 126.45, 124.11, 122.52, 119.84, 107.89. IR
24
1
m.p. 226–227°C (Lit. 226–227°C); H NMR (400 MHz, CDCl ):
G 8.19 (s, 1H, ArH), 7.85 (d, J = 8.0 Hz, 2H, ArH), 7.64–7.67 (m,
3
(KBr): 1646, 1610, 1454, 1340, 1135,922, 841,772,679,627. MS (EI):
+
m/z (%) = 267 (100) [M ], 267 (35), 221 (22), 165 (32), 139(19), 102
61). Anal. Calcd for C H NO : C, 67.42; H, 3.39; N, 5.24; Found:
13
1
H, ArH), 7.51–7.54 (m, 3H, ArH), 6.79 (s, 1H, CH). C NMR (100
(
1
5
9
4
MHz, CDCl ): G 176.98, 162.51, 154.49, 138.21, 134.09, 131.40,
3
C, 67.44; H, 3.43; N 5.21%.
1
1
29.90, 129.47, 127.57, 125.25, 124.94, 119.75, 107.63. IR (KBr):
6
-methoxy-2-(4-nitrophenyl)-4H-chromen-4-one (1s): Pale yellow
658, 1492, 1438, 1092, 906, 831, 664. MS (EI): m/z (%) = 290 (10)
10 1
solid: m.p. 200.1–201.8°C (lit. 198–200°C); H NMR (400 MHz,
+
+
[
M ], 293 (M + 2, 2), 262 (100), 199 (60), 163 (87).
CDCl ), G 8.39 (d, J = 8.0 Hz, 2H, ArH), 8.11 (t, J = 4.0 Hz, 2H, ArH),
3
2
-(4-chlorophenyl)-6-methyl-4H-chromen-4-one (1k): Pale yellow
24 1
7
(
.61 (d, J = 4.0 Hz,1H, ArH), 7.55 (d, J = 8.0 Hz,1H, ArH),7.33–7.36
solid: m.p. 198–199°C (Lit. 198–199°C); H NMR (400 MHz,
CDCl ): G 7.99 (s, 1H, ArH), 7.83 (d, J = 8.4 Hz, 2H, ArH), 7.43–7.51
13
m, 1H, ArH), 6.90 (s, 1H, CH), 3.96 (s, 3H, CH ). C NMR (100
3
3
MHz, CDCl ), G 177.90, 160.343, 157.40, 151.02, 149.37, 137.75,
13
3
(
m, 4H, ArH), 6.76 (s, 1H, CH), 2.46 (s, 3H, CH ). C NMR (100
3
1
(
27.16, 124.58, 124.45, 124.25, 119.60, 108.80, 104.90, 56.01. IR
MHz, CDCl ): G 178.30, 161.97, 154.37, 137.70, 135.32, 135.06,
3
KBr): 1642, 1607, 1518, 1488, 1347, 1020, 853, 826, 697. MS (EI):
1
30.26, 129.27, 127.43, 125.01, 123.48, 117.73, 107.43, 20.86.
+
m/z (%) = 297 (100) [M ], 267 (28), 150 (60), 107 (43), 79 (32).
IR (KBr): 1643, 1621, 1483, 1089, 902, 820, 707. MS (EI): m/z (%) =
+
2
70 (100) [M ], 272 (40), 242 (30), 235 (15), 134 (95), 106 (20).
-methyl-2-phenyl-4H-chromen-4-one (1l): Yellow solid:
We are grateful to the National Natural Science Foundation
of China (Nos. 20676123 and 20876147) and Wenzhou
8QLYHUVLW\ꢂIRUꢂ¿QDQFLDOꢂVXSSRUWꢄ
6
24
1
m.p. 121–122°C (Lit. 122°C); H NMR (400 MHz, CDCl ): G 8.00
3
(
s, 1H, ArH), 7.90 (d, J = 8.0 Hz, 2H, ArH), 7.43–7.52 (m, 5H, ArH),
13
6
.79 (s, 1H, CH), 2.45 (s, 3H, CH ). C NMR (100 MHz, CDCl ):
3 3
G 178.46, 163.14, 154, 43, 135,10, 134,90, 131.78, 131.42, 128.92,
Received 7 October 2008; accepted 27 October 2008
Paper 08/0210 doi: 10.3184/030823409X396409
Published online: 21 January 2009
1
1
2
26.16, 124.93, 123.51, 117,76, 107.31, 20.85. IR (KBr): 1638, 1615,
+
482, 1359, 1044, 883, 814, 778. MS (EI): m/z (%) = 236 (100) [M ],
08 (30), 134 (71), 106 (17), 78 (12).
6
-methyl-2-(4-nitrophenyl)-4H-chromen-4-one (1m): Yellow solid:
24
1
m.p. 276–278°C (Lit. 275–277°C); H NMR (400 MHz, CDCl ):
G 8.39 (d, J = 8.0 Hz, 2H, ArH), 8.11 (d, J = 8.0 Hz, 2H, ArH), 8.03
References
1
2
3
3
J.B. Harborne and C.A. Williams, Nat. Prod. Rep., 2001, 18, 310.
V.M. Malirov and M.P. Yuldashev, Chem. Nat. Compd., 2002, 38, 358.
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A. Mantas, E. Deretey, F.H. Ferretti, M.R. Estrada and I.G. Csizmadia,
Theochem, 2000, 504, 171.
(
s, 1H, ArH), 7.50–7.58 (m, 2H, ArH), 6.90 (s, 1H, CH), 2.49 (s, 3H,
13
CH ). C NMR (100 MHz, CDCl ): G 178.16, 160,43, 154.52, 149.43,
3
3
1
37.82, 135.88, 135.56, 127.19, 125.27, 124.22, 123.73, 117.89,
09.53,20.96. IR (KBr): 1639, 1617, 1522, 1343, 1138, 850, 823, 691.
1
4
5
+
MS (EI): m/z (%) = 281 (100) [M ], 253 (20), 134 (48), 106 (12).
6
-methyl-2-p-tolyl-4H-chromen-4-one (1n): White solid: m.p. 151–
24 1
6
7
8
K. Venkataraman, J. Chem. Soc., 1929, 2219.
1
52°C (Lit. 150–151°C); H NMR (400 MHz, CDCl ): G 8.00 (s, 1H,
3
S. Saxena, J.K. Makrandi and S.K. Grover, Synthesis, 1985, 697.
R.J. Fitzmaurice, Z.C. Etheridge, E. Jumel, D.N. Woolfson and
S. Caddick, Chem. Commun., 2006, 4814.
ArH), 7.80 (d, J = 8.0 Hz, 2H, ArH), 7.44–7.50 (m, 2H, ArH), 7.31 (d,
J = 8.0 Hz, 2H, ArH), 6.77 (s, 1H, CH), 2.46 (s, 3H, CH ), 2.43 2.46
3
13
(
s, 3H, CH ). C NMR (100 MHz, CDCl ): G 178.49, 163.42, 154.50,
3
3
9
E.U. Mughal, M. Ayaz, S. Hussain and M.I. Choudhary, Bioorg. Med.
Chem., 2006, 14, 4704.
1
42.06, 135.03, 134.80, 129.70, 129.08, 126.16, 125.01, 123.64,
1
17.77, 106.81, 21.45, 20.88. IR (KBr): 1643, 1613, 1483, 817. MS
10 M. Kucukislamoglu, M. Nebioglu, M. Zengin, M. Arslan and N. Yayli,
J. Chem. Res., 2005, 556.
+
(
EI): m/z (%) = 250 (100) [M ], 235 (30), 222 (25), 134 (80), 115 (17),
1
06 (17), 78 (10).
-methyl-2-phenyl-4H-chromen-4-one (1o): Pale yellow solid: m.p.
11 P. Vázquez, L. Pizzio, G. Romanelli, J. Autino, C. Cáceres and M. Blanco,
Appl. Catal., A (General), 2002, 235, 233.
7
22
1
12 J.K. Makrandi and V. Kumari, Chem. Ind., 1988, 630.
1
29–131°C (Lit. 128–130°C); H NMR (400 MHz, CDCl ): G 8.14
3
13
14
15
A. Nishinaga, K. Maruyama, H. Ando, R. Sato, T. Mashino, A. Inada and
T. Nakanishi, Tetrahedron Lett., 1990, 31, 3171.
(
s, 1H, ArH), 7.91 (d, J = 8.0 Hz, 2H, ArH),7.51 (s, 3H, ArH), 7.35 (s,
1
H, ArH), 7.22 (d, J = 8.0 Hz, 1H, ArH), 6.81 (s, 1H, CH), 2.50 (s, 3H,
D.O. Bennardi, G.P. Romanelli, J.C. Autino and L.R. Pizzio, Appl. Catal.,
A (General), 2007, 324, 62.
13
CH ). C NMR (100 MHz, CDCl ): G 178.37, 162.99, 156.30, 145.02,
3
3
1
31.78, 131.38, 128.91, 126.62, 126.12, 125.35, 121.66, 117.78,
07.45, 21.76. IR (KBr): 1637, 1606, 1449, 1371, 1157, 866, 772. MS
G.W. Kabalka and A.R. Mereddy, Tetrahedron Lett., 2005, 46, 6315.
1
16 W.K. Su, J.X. Chen, H.Y. Wu and C. Jin, J. Org. Chem., 2007, 72, 4524.
17 J.X. Chen, H.Y. Wu, Z.G. Zheng, C. Jin, X.X. Zhang and W.K. Su,
Tetrahedron Lett., 2006, 47, 5383.
+
(
EI): m/z (%) = 236 (100) [M ], 208 (53), 134 (45), 106 (16), 78 (12).
6
-chloro-2-p-tolyl-4H-chromen-4-one (1p): Yellow solid:
24
1
18 W.K. Su and C. Jin, Org. Lett., 2007, 9, 993.
m.p. 183–184°C (Lit. 183–184°C); H NMR (400 MHz, CDCl ):
3
19
20
D. Nagarathnam and M. Cushman, Tetrahedron, 1991, 28, 5071.
A. Nishinaga, H. Ando, K. Maruyama and T. Mashino, Synthesis, 1992,
839.
G 8.16 (s, 1H, ArH), 7.78 (d, J = 8.0 Hz, 2H, ArH), 7.61 (d, J = 8.0 Hz,
1
H, ArH), 7.50 (d, J = 8.0 Hz, 1H, ArH), 7.31 (d, J = 8.0 Hz, 2H,
13
ArH), 6.79 (s, 1H, CH), 2.43 (s, 3H, CH ). C NMR (100 MHz,
3
2
1
X. Huang, E. Tang, W.M. Xu and J. Cao, J. Comb. Chem., 2005, 7, 802.
CDCl ): G 177.08, 163.79, 154.46, 142.55, 133.76, 131.02, 129,78,
3
22 P. Kumar and M.S. Bodas, Org. Lett., 2000, 2, 3821.
1
28.45, 126.18, 125.07, 119.72, 106.75, 21.51. IR (KBr): 1641, 1613,
2
3
4
N.J. Reddy, M. Bokadia and T. Sharma, J. Org. Chem., 1981, 46, 638.
O.V. Singh, M. Muthukrishnan and G. Raj, Synth. Commun., 2005, 35,
2723.
+
1
465, 1436, 1358, 816, 670. MS (EI): m/z (%) = 270 (100) [M ], 272
2
(35), 255 (45), 242 (20), 154 (55), 116 (31), 115 (47).
6
-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (1q): White
25 O. Prakash and S. Pahuja, Synth. Commun., 1990, 20, 1417.