Vanadium-catalyzed synthesis of 4(3H)-quinazolinones from anthranilamides and aryl aldehydes

Article abstract of DOI:10.1080/00397911.2012.717669

An efficient synthesis of 2-substituted and 2,3-disubstituted quinazolin-4(3- H)-ones via tandem reaction of anthranilamides and aromatic aldehydes catalyzed by vanadyl acetylacetonate with 1 mol% loading under an air atmosphere is described. This new method is associated with several advantages such as low catalyst loading (only 1 mol%), use of green oxidant in the form of air, high atom economy, and good to excellent yields. A mechanism of vanadium-catalyzed synthesis of 4(3H)-quinazolinones has also been proposed. Copyright

Full text of DOI:10.1080/00397911.2012.717669

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Vanadium-Catalyzed Synthesis of 4(3H)-
Quinazolinones from Anthranilamides
and Aryl Aldehydes
a
b
a
a
Dan Zhan , Tianbin Li , Xiaoping Zhang , Chuan Dai , Haidong
a
a
a
Wei , Yuyu Zhang & Qingle Zeng
a
Institute of Green Catalysis and Synthesis, College of Materials
and Chemistry and Chemical Engineering, Chengdu University of
Technology , Chengdu , China
b
State Key Laboratory of Geohazard Prevention and
Geoenvironment Protection, Chengdu University of Technology ,
Chengdu , China
Accepted author version posted online: 26 Mar 2013.Published
online: 03 Jun 2013.
To cite this article: Dan Zhan , Tianbin Li , Xiaoping Zhang , Chuan Dai , Haidong Wei , Yuyu Zhang
&
Qingle Zeng (2013): Vanadium-Catalyzed Synthesis of 4(3H)-Quinazolinones from Anthranilamides
and Aryl Aldehydes, Synthetic Communications: An International Journal for Rapid Communication of
Synthetic Organic Chemistry, 43:18, 2493-2500
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1
Synthetic Communications , 43: 2493–2500, 2013
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2012.717669
VANADIUM-CATALYZED SYNTHESIS
OF 4(3H)-QUINAZOLINONES FROM
ANTHRANILAMIDES AND ARYL ALDEHYDES
1
Dan Zhan, Tianbin Li, Xiaoping Zhang, Chuan Dai,
2
1
1
1
Haidong Wei, Yuyu Zhang, and Qingle Zeng
1
1
1
Institute of Green Catalysis and Synthesis, College of Materials and
Chemistry and Chemical Engineering, Chengdu University of Technology,
Chengdu, China
2
State Key Laboratory of Geohazard Prevention and Geoenvironment
Protection, Chengdu University of Technology, Chengdu, China
GRAPHICAL ABSTRACT
Abstract An efficient synthesis of 2-substituted and 2,3-disubstituted quinazolin-4(3-
H)-ones via tandem reaction of anthranilamides and aromatic aldehydes catalyzed by vana-
dyl acetylacetonate with 1 mol% loading under an air atmosphere is described. This new
method is associated with several advantages such as low catalyst loading (only 1 mol%),
use of green oxidant in the form of air, high atom economy, and good to excellent yields. A
mechanism of vanadium-catalyzed synthesis of 4(3H)-quinazolinones has also been
proposed.
Supplemental materials are available for this article. Go to the publisher’s online edition
of Synthetic Communications to view the free supplemental file.
1
Keywords Anthranilamides; aromatic aldehydes; domino reaction; quinazolin-4(3-
H)-ones; vanadyl acetylacetonate
INTRODUCTION
(3H)-Quinazolinones are an important class of nitrogen-containing hetero-
4
cycles with various pharmacological and therapeutic properties, such as anticancer,
[
1]
2
[3]
[4]
[5]
anti-inflammatory, antibacterial, antihypertensive, vasopressin V3 receptor
Received February 19, 2012.
Address correspondence to Qingle Zeng, Institute of Green Catalysis and Synthesis, College of
Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu
610059, China. E-mail: qlzeng@cdut.edu.cn
2
493

2494
D. ZHAN ET AL.
[
6]
[7]
antagonists, and nonpeptide CCK-B antagonists. Hence, the efficient synthesis of
quinazolinones derivatives has assumed enormous significance.
Various protocols for the synthesis of quinazolin-4(3H)-ones have been investigated
in the past. Some common methods include condensation of 2-aminobenzamides and
[8]
substituted benzoyl chlorides or their equivalents in ionic liquid, tandem condensation,
[9]
and C-N cross coupling of 2-halobenzoic acids and amidines,
cyclization
[12]
N-arylorthanilamides,
[10]
of o-acylaminobenzamides,
[11]
2-amino-benzonitrile,
[13]
[14]
nitroenes, and aza-Wittig reactions of a-azido-substituted aromatic imides. However,
most of these procedures have some drawbacks such as poor atom economy, use of envir-
onmentally toxic reagents or media, use of expensive chemicals, and harsh reaction con-
ditions. In addition, some three-component condensation reactions of isatoic anhydride=
[15]
anthranilic acid, ortho esters, and amines have been reported, but these approaches again
lack atom economy. Relatively recently, Xu et al. reported CuBr-catalyzed domino syn-
thesis of 2-aryl 4(3H)-quinazolinones via Ullmann-type coupling of ortho-iodobenzamides
and benzyl amines or a-amino acids (decarboxylation of a-amino acids as the substrates),
[16]
and aerobic oxidative C-H amidation. Unfortunately, both approaches lead to the gen-
eration of undesired by-products, such as hydrogen iodide (HI), which consumes K CO ,
2
3
making the overall process less efficient in terms of atom economy.
In 1994, Abdel-Jalil et al. introduced a new synthetic protocol for 2-substituted
4
heteroaryl aldehydes and 3 equivalents of CuCl as the oxidant and catalyst.
(3H)-quinazolinones: cascade condensation of anthranilamide and aryl, alkyl, and
[
17]
2
Synthesis of the desired product from anthranilamide and aldehydes is not only atom
economical but also environmentally-friendly as water is the only water major
by-product of the reaction.
Later a similar protocol with 2 equivalents of FeCl as the oxidant and catalyst was
3
[18]
reported. In 2010, Wang et al. developed an iodine-catalyzed approach in ionic liquid
with the same class substrates, that is, anthranilamide and aldehydes, but the loading of
iodine was not given in their main article or its supporting information, nor was any men-
tion made in their general procedure for the synthesis of 2-arylquinazolin-4(3H)-one and
[
19]
(E)-2-arylideneaminobenzamide.
one-pot, three-component route to synthesize 2,3-disubstituted 4(3H)-quinazolinones
Similar to this work, Dabiri et al. reported a
[20]
in the presence of an equivalent amount of iodine as the catalyst. All the aforemen-
tioned methods with anthranilamides and aldehydes as substrates involve using stoichio-
metric instead of catalytic amounts of various chemicals; usually the reactions required
more than 1 equiv. of CuCl , FeCl , and iodine. Therefore, in the present study we tried
2
3
to discover an optimal catalyst for the reaction with appreciably lower loading. Keeping
[21]
this in mind, in continuation of our research on vanadium-catalyzed sulfide oxidation,
herein we report an efficient vanadium-catalyzed synthesis of 4(3H)-quinazolinones in
the presence of only 1mol% catalyst (Scheme 1).
Scheme 1. Vanadium-catalyzed synthesis of 4(3H)-quinazolinones.

SYNTHESIS OF 4(3H)-QUINAZOLINONES
2495
RESULTS AND DISCUSSION
To find a catalytic system for the synthesis of 4(3H)-quinazolinones from
anthranilamides (1) and aldehydes (2), anthranilamide and benzaldehyde were used
as the model substrates, and various metal salts and complexes were evaluated
(Table 1). Because stoichiometric CuCl and FeCl were reported to be efficient
for the synthesis of 4(3H)-quinazolinones, they were adopted in our research as
2 3
ꢀ
potential catalyst candidates. Under air and at 120 C, CuCl - and FeCl -catalyzed
2
3
tandem condensation and oxidation of anthranilamide and benzaldehyde for 24 h
with 1 mol% catalyst loading afforded 2-phenyl-4(3H)-quinazolinone (3a) with mod-
erate yields of 72% and 64%, respectively (Table 1, entries 1 and 2).
a
Table 1. Screening of various reaction conditions
b
Entry
Catalyst
Solvent
Time (h)
Yield (%)
1
2
3
CuCl
FeCl
Fe(NO
2
DMSO
DMSO
DMSO
24
24
24
72
64
80
3
3
)
3
ꢁ H O
2
4
5
DMSO
DMSO
24
24
82
84
6
7
8
VO(SO
4
)
DMSO
DMSO
DMF
24
24
24
15
15
24
15
13
7
84
88
68
13
6
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
VO(acac)
2
2
2
2
2
2
2
2
2
2
c
9
d
Ethanol
1
1
1
1
1
1
1
0
1
2
3
4
5
6
2
H O
DMA
DMA
DMA
DMA
DMA
DMA
95
97
88
53
34
77
5
15
d
a
Reaction conditions: Metal salt (0.01 mmol), anthranilamide (1 mmol), benzaldehyde (1 mmol), and
ꢀ
DMA (3 mL), at 120 C for 15 h, unless otherwise mentioned.
b
Isolated yield.
ꢀ
c
7
8 C.
ꢀ
d
1
00 C.

2496
D. ZHAN ET AL.
As ferric nitrate [Fe(NO ) ] has already been successfully employed in the aero-
3
3
[22]
bic oxidation of alcohols and sulfides,
ation. Ferric nitrate efficiently accomplished the transformation from
it was attempted by us in this transform-
anthranilamide and benzaldehyde to afford 2-phenyl-4(3H)-quinazolinone (3a) in
8
0% yield (entry 3).
Inspired by the study of vanadium-catalyzed oxidative coupling of 2-naphthol to
0
[23]
1
,1 -bi-2-naphthol,
N-salicylidene vanadyl carboxylate-catalyzed enantioselective
[24]
aerobic oxidation of a-hydroxy esters and amides,
vanadium-catalyzed enantioselective sulfide oxidation,
and our research of
some vanadium complexes
[21]
and salts were used in the catalytic synthesis of 2-phenyl-4(3H)-quinazolinone (3a).
Vanadyl carboxylates derived from N-salicylidene-valine and N-salicylidene-
phenylalanine gave 2-phenyl-4(3H)-quinazolinone with 82% and 84% yields, respect-
ively (entries 4 and 5). A simple vanadyl sulfate gave the same yield (entry 6). Vanadyl
acetylacetonate afforded a better yield of 88% (entry 7).
The result is probably attributed to the fact that vanadyl acetylacetonate
increases the condensation of anthranilamide and benzaldehyde to form an imide
intermediate, and more significantly, hugely promotes aerobic oxidation of the imide
intermediate to give 2-phenyl-4(3H)-quinazolinone (3a). As mentioned, vanadium
[
23]
can efficiently catalyze aerobic oxidative coupling of 2-naphthol,
esters, and amides.
a-hydroxy
[24]
To obtain an ideal result, some other solvents were also screened. While reac-
ꢀ
tion in dimethyl formamide (DMF) at 120 C gave a lower yield (Table 1, entry 8),
water and ethanol were proved to be poor solvents to dissolve anthranilamide and
2
-phenyl-4(3H)-quinazolinone (3a) and gave extremely poor yields at lower tem-
peratures (entries 9 and 10). To our surprise, the solvent DMA (N,N-dimethylace-
tamide) afforded an excellent result with 95% yield (entry 11). The further
examination of reaction time demonstrated that longer reaction time of 24 h was
not necessary. However, when the reaction time was too short, the starting materi-
als could not be effectively transformed into the product (entries 12 to 15), and the
optimized time was set as 15 h (entry 12). Decreasing the temperature resulted in
lower yields (entry 16).
With the optimized reaction conditions in hand, a series of anthranilamides
and aldehydes were investigated (Table 2, Scheme 1). Under the optimized
conditions, vanadyl acetylacetonate–catalyzed cascade condensation and aerobic oxi-
0
dation of 4-methylbenzaldehyde and anthranilamide afforded 2-(4 -methylphenyl)-
4
(
(3H)-quinazolinone (3b) with a fairly good yield similar to that of benzaldehyde
entry 2 vs. 1).
Aromatic aldehydes with electron-donating groups demonstrate excellent
performance in the reaction (Table 2, entries 3 to 5). Reaction of 3-methoxylbenzal-
0
dehyde and anthranilamide gave 2-(3 -methoxylphenyl)-4(3H)-quinazolinone (3c)
0
with the great yield of 99% (entry 3). Reaction of 4-(N,N -dimethyl)benzaldehyde
gave the corresponding 4(3H)-quinazolinone (3d) with a good yield (entry 4). To
our surprise, a much more complex aldehyde 3,5-di-tert-butylsalicylaldehyde with
a free phenolic hydroxyl group also afforded the target product (3e) with excellent
yield (entry 5).
Vanadium-catalyzed cascade condensation and aerobic oxidation of aromatic
aldehydes with electron-withdrawing groups and anthranilamide also afforded the

SYNTHESIS OF 4(3H)-QUINAZOLINONES
2497
a[25]
Table 2. Synthesis of 2-substituted and 2,3-disubstituted quinazolin-4(3H)-ones
0
00
b
Entry
R
H
R
R
Product
Yield (%)
1
2
3
4
5
6
7
8
9
Ph
H
H
H
H
H
H
H
H
H
H
H
H
3a
3b
3c
3d
3e
3f
97
95
99
84
95
96
79
85
78
99
92
80
63
4-CH
3-CH
3
C
6
4
H
H
H
H
H
H
H
H
H
H
H
H
3
6
OC H
4
4-N(CH
3,5-tBu
4-FC
4-ClC
3
)
2
C
6
H
4
2
6 2
-2-OHC H
6
H
4
6
H
4
3g
3h
3i
4-BrC
3-BrC
2-BrC
Furyl
Ph
6
6
6
H
H
H
4
4
4
10
11
12
13
3j
3k
3l
3 7
C H
Ph
CH
2
C
6
H
5
3m
a
2
Reaction conditions: VO(acac) (0.01 mmol), anthranilamide (1 mmol), substituted benzaldehyde
ꢀ
(
1 mmol), and DMA (3 mL), at 120 C for 15 h.
b
Isolated yield.
corresponding 4(3H)-quinazolinones with good to excellent yields (Table 2, entries 6
0
to 10). para-Fluorobenzaldehyde produced 2-(4 -flurophenyl)-4(3H)-quinazolinone
(3f) with up to 95% yield (entry 6). para-Chloro- and para-bromo-benzaldehyde also
gave the product (3g, 3h) with good yields (entries 7 and 8).
para-, meta-, and ortho-substituted benzaldehydes all afforded good to excellent
yields (Table 2, entries 9 to 11). para- and meta-bromobenzaldehydes produced the
corresponding products (3i, 3j) with good yields (entries 9 and 10). Again, surprisingly
0
ortho-bromobenzaldehyde afforded 2-(2 -bromophenyl)-4(3H)-quinazolinone with
up to 99% yield (entry 10).
Furthermore, vanadium-catalyzed cascade condensation and aerobic oxidation
of heteroaromatic aldehyde furfural and anthranilamide gave 2-furyl-4(3H)-
quinazolinone (3k) with up to 92% yield (Table 2, entry 11).
Besides nonsubstituted anthranilamide, substitution on the amide group of anthra-
nilamide gave moderate to good yields (Table 2, entries 12 and 13). Perhaps because of the
steric hindrance exerted by benzyl and 2-amino-N-benzylbenzamide groups, a moderate
yield of 2-phenyl-3-benzyl-4(3H)-quinazolinone (3m) was achieved (entry 13).
To account for the observed results, we reasoned that the vanadium-catalyzed
reaction probably acts through a different mechanistic pathway compared to those
[
15d,16a,19]
reported earlier with other catalytic systems and synthetic methods.
The
plausible mechanism of vanadium-catalyzed synthesis of 4(3H)-quinazolinones is
depicted in Scheme 2.
In conclusion, we have demonstrated for the first time that vanadyl acetylace-
tonate could be used as an efficient catalyst for the selective synthesis of 2-substituted

2498
D. ZHAN ET AL.
Scheme 2. Proposed mechanism of vanadium-catalyzed synthesis of 4(3H)-quinazolinones.
and 2,3-disubstituted 4(3H)-quinazolinones with air as the oxidant. The salient fea-
tures include environmentally friendly air as the oxidant, low catalyst loading (only
1
mol%), good to excellent yields, high atom economy, cheap and readily available
reagents, and easy operation to make the present method superior to the existing
methods for the synthesis of 4(3H)-quinazolinones. A plausible mechanism has been
proposed to support the experimental observations.
EXPERIMENTAL
The purities of all the synthesized compounds were checked by thin-layer chro-
matography (TLC) using different organic solvents. The infrared (IR) spectra were
recorded on a Bruker Tensor-27 Fourier transform (FT)–IR spectrophotometer in
1
KBr discs. H NMR spectra were recorded on a Bruker Advance 300-MHz NMR
or 400-MHz spectrometer in CDCl or dimethylsulfoxide (DMSO-d ) containing tet-
3
6
ramethylsilane (TMS) as an internal standard. Melting points were determined on an
Electrothermal melting-point apparatus.
The chemicals and reagents were purchased from Aldrich, Acros, Alfa Aesar,
Aladdin, or Kelong chemical companies and were used without further purification.
General Procedure for the Synthesis of 4(3H)-Quinazolinones
A mixture of anthranilamide (1.0 mmol), benzaldehyde (1.0 mmol), and cata-
lyst (0.01 mmol vanadyl acetylacetonate) in DMA (3 ml) was stirred in an oil bath
ꢀ
at 120 C for 15 h. After completion of the reaction, the reaction mixture was cooled
to room temperature, quenched with a saturated solution of NaCl, extracted with
ethyl acetate (3 ꢂ 10 mL), and then washed with water. The organic phase was dried
over Na SO and filtered, and then the solvent was removed under reduced pressure.
2
4
The crude product was purified by column chromatography on silica gel (gradient
eluent with a mixed solution of petroleum ether and ethyl acetate) to give the pure
4
(3H)-quinazolinone.
2-Phenyl-4(3H)-quinazolinone (3a)
ꢀ
1
White solid. Mp: 239–241 C. H NMR (300 MHz, CDCl ), d (ppm): 11.12 (s,
3
1
H), 8.33 (d, J ¼ 7.52 Hz, 1H), 8.20–8.22 (m, 2H) 7.78–7.85 (m, 2H), 7.59 (t,
1
3
J ¼ 2.78 Hz, 3H) 7.51(t, J ¼ 3.19 Hz, 1H). C NMR (75 MHz, CDCl ), d (ppm):
3
1
63.6, 151.6, 149.5, 134.8, 132.8, 131.6, 129.0, 128.0, 127.3, 126.8, 126.5, 120.8.
-
ꢃ1
ESI-MS (negative mode), m=z ¼ 221 [M–H] . IR (KBr), n (cm ): 2924, 1730,
664, 1601, 1451, 1375, 1212, 1045, 942, 752, 694.
1

SYNTHESIS OF 4(3H)-QUINAZOLINONES
2499
ACKNOWLEDGMENTS
We thank the National Science Foundation of China (No. 20672088), the
Ministry of Human Resources and Social Security of the People’s Republic of China
(No. ZF0022), the Science and Technology Bureau of Sichuan (No. 2011HH0016),
the Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenviron-
ment Protection (No. SKLGP2012K005) and the Cultivating Program for Excellent
Innovation Team of Chengdu University of Technology (No. HY0084) for providing
the necessary financial support. We thank Pinaki Bhadury for his comments.
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