NH2SO3H and H6P2W 18O6218H2O-catalyzed, three-component, one-pot synthesis of benzo[ c[acridine derivatives

Article abstract of DOI:10.1080/00397911.2010.550704

We report here two simple methods for the synthesis of benzo[c]acridine derivatives from three-component, one-pot condensation of 1-naphthylamine, dimedone, and a variety of substituted aldehydes in the presence of a catalytic amount of NH₂SO

Full text of DOI:10.1080/00397911.2010.550704

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NH2SO3H and H6P2W18O62 · 18H2O-
Catalyzed, Three-Component, One-
Pot Synthesis of Benzo[c]acridine
Derivatives
Majid M. Heravi a , Hamideh Alinejhad a , Fatemeh Derikvand a
,
Hossein A. Oskooie a , Bita Baghernejad a & Fatemeh F. Bamoharram
b
a Department of Chemistry, School of Sciences, Azzahra University,
Vanak, Tehran, Iran
b Department of Chemistry, Islamic Azad University, Mashhad
Branch, Mashhad, Iran
Accepted author version posted online: 27 Oct 2011.Published
online: 26 Mar 2012.
To cite this article: Majid M. Heravi , Hamideh Alinejhad , Fatemeh Derikvand , Hossein A. Oskooie ,
Bita Baghernejad & Fatemeh F. Bamoharram (2012) NH2SO3H and H6P2W18O62 · 18H2O-Catalyzed,
Three-Component, One-Pot Synthesis of Benzo[c]acridine Derivatives, Synthetic Communications:
An International Journal for Rapid Communication of Synthetic Organic Chemistry, 42:14, 2033-2039,
DOI: 10.1080/00397911.2010.550704
To link to this article: http://dx.doi.org/10.1080/00397911.2010.550704
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Synthetic Communications1, 42: 2033–2039, 2012
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2010.550704
NH2SO3H AND H6P2W18O62 ꢀ 18H2O-CATALYZED,
THREE-COMPONENT, ONE-POT SYNTHESIS OF
BENZO[c]ACRIDINE DERIVATIVES
Majid M. Heravi,1 Hamideh Alinejhad,1 Fatemeh Derikvand,1
Hossein A. Oskooie,1 Bita Baghernejad,1 and
Fatemeh F. Bamoharram2
1Department of Chemistry, School of Sciences, Azzahra University,
Vanak, Tehran, Iran
2Department of Chemistry, Islamic Azad University, Mashhad Branch,
Mashhad, Iran
GRAPHICAL ABSTRACT
Abstract We report here two simple methods for the synthesis of benzo[c]acridine
derivatives from three-component, one-pot condensation of 1-naphthylamine, dimedone,
and a variety of substituted aldehydes in the presence of a catalytic amount of NH2SO3H
or H6P2W18O62 ꢀ 18H2O under solvent-free conditions at 120 ꢁC or in refluxing ethanol.
Keywords Benzo[c]acridine; H6P2W18O62 ꢀ 18H2O; multicomponent one-pot reactions;
NH2SO3H; solvent-free conditions
INTRODUCTION
Solid acids can play a significant role in the development of cleaner
technologies.[1] They have emerged as a substitute for conventional acidic catalysts
in different areas of organic synthesis.[2–4] A large number of 1,4-dihydropyridine
derivatives have pharmacological applications. They are calcium channel blockers
and are widely used in the treatment of arterial hypertension and ischemic heart dis-
ease.[5] The chemical modifications of the dihydropyridine (DHP) ring and variations
with different substituents[6] or heteroatoms,[7] afforded some insight into the mol-
ecular interactions at the receptor level. Acridine derivatives containing 1,4-DHP
are well-known compounds for their pharmacological profile in calcium channel
modulations.[8] They can be synthesized by various methods,[9–11] and recently some
Received September 7, 2010.
Address correspondence to Majid M. Heravi, Department of Chemistry, School of Sciences,
Azzahra University, Vanak, Tehran 1234, Iran. E-mail: mmh1331@yahoo.com
2033

2034
M. M. HERAVI ET AL.
Scheme 1. The total reaction for the synthesis of benzo[c]acridines.
new methods have been reported for the construction of acridine derivatives via
condensing N-arylidenenaphthalen-1-amine with dimedone in the presence of
triethylbenzyl ammonium chloride (TEBAC) or benzyltriethylammonium bromide
(BTEA) in water under heating conditions.[12–14]
The use of multicomponent, reactions (MCRs) to generate remarkable and
new druglike scaffolds is replete in the recent chemical literature.[15]
As a consequence of our interest in the development of new routes to hetero-
cyclic systems from multicomponent, one-pot protocols,[16–18] herein we report two
highly efficient methods for the three-component, one-pot synthesis of a series of
polyhydroacridine derivatives via the reaction of 1-naphthylamine, dimedone, and
a variety of aldehydes catalyzed by sulfamic acid (SA) or H6P2W18O62 ꢀ 18H2O as
a Wells–Dawson-type heteropolyacid (HPA) in a solvent-free system or in refluxing
ethanol (Scheme 1).
RESULTS AND DISCUSSION
The procedures are very simple: 1 equiv. of 1-naphthylamine was mixed with
1 equiv. of aldehyde, 1 equiv. of dimedone, and 0.1 equiv. of NH2SO3H or 0.01 equiv.
Table 1. Synthesis of benzo[c]acridine derivatives under solvent-free conditions
Mp (ꢁC)
Entry
Ar-
Product
Catalyst
Observed
Reported
Time (min)
Yield (%)a
1
2
Ph
4a
4b
4c
4d
4e
4f
SA
SA
261–262
269–270
277–278
266–267
282–283
314–315
257–259
261–262
269–270
277–278
266–267
282–283
314–315
257–259
261–262
260–262[19]
267–269[20]
275–278[20]
265–266[20]
280–282[20]
312–315[20]
257–258[20]
260–262[20]
267–269[20]
275–278[20]
265–266[20]
280–282[20]
312–315[20]
257–258[20]
260–262[20]
110
110
110
100
105
130
135
90
70
75
70
70
75
65
75
70
75
75
70
75
80
60
70
3-NO2-Ph
2-Cl-Ph
4-Cl-Ph
3
SA
SA
4
5
2,4-Cl2-Ph
4-HO-Ph
4-MeO-Ph
4-NMe2-Ph
Ph
SA
SA
6
7
4g
4h
4a
4b
4c
4d
4e
4f
SA
SA
8
9
HPA
HPA
HPA
HPA
HPA
HPA
HPA
100
95
10
11
12
13
14
15
3-NO2-Ph
2-Cl-Ph
4-Cl-Ph
90
85
2,4-Cl2-Ph
4-HO-Ph
4-MeO-Ph
95
120
135
4g
aYields were analyzed by GC.

SYNTHESIS OF BENZO[c]ACRIDINE DERIVATIVES
2035
Table 2. Synthesis of benzo[c]acridine derivatives catalyzed in refluxing ethanol
Entry
Ar-
Catalyst
Time (min)
Yield (%)a
1
2
Ph
3-NO2-Ph
4-Cl-Ph
SA
SA
85
80
80
85
95
90
80
80
70
70
70
65
70
70
70
60
70
68
72
75
70
60
3
SA
SA
4
2-Me-Ph
4-HO-Ph
4-MeO-Ph
Ph
5
SA
SA
6
7
HPA
HPA
HPA
HPA
HPA
8
3-NO2-Ph
4-Cl-Ph
9
10
11
2-Me-Ph
4-MeO-Ph
aYields were analyzed by GC.
Table 3. Recovery of the NH2SO3H in the synthesis of 10,10-dimethyl-7-(3-nitrophenyl)-7,9,10,11-
tetrahydro-9H-benzo[c]acridin-8-one
Entry
Reaction conditions
Number of cycles
Yields (%)a
1
2
Solvent free, 120 ꢁC, 80 min
Refluxing ethanol, 110 min
5
5
70, 68, 68, 65, 60
75, 70, 67, 65, 65
aYields were analyzed by GC.
of H6P2W18O62 ꢀ 18H2O and heated at 120 ꢁC under solvent-free conditions or
refluxed in ethanol (5 mL) for an appropriate time.
The scope and generality of these methods are illustrated with respect to vari-
ous aromatic aldehydes, and the results are summarized in Tables 1 and 2. These
one-pot procedures work well for a wide range of substrates. Various substituted
aldehydes were reacted with 1-naphthylamine and dimedone to give excellent yields
of the desired products. As shown in Tables 1 and 2, the electron-withdrawing or
electron-donating group on the phenyl rings did not affect the reaction.
It is noteworthy to mention that the catalyst is recyclable and could be reused
without significant loss of activity (Table 3).
Scheme 2. Mechanism for the synthesis of benzo[c]acridines.

2036
M. M. HERAVI ET AL.
A probable mechanism for this condensation reaction is patterned in Scheme 2,
which begins with the condensation of dimedone and aldehyde catalyzed by
Brønsted acids.
CONCLUSIONS
In summary, we report here a high-yielding, simple, convenient, straight-
forward, and practical three-component, one-pot procedure for the synthesis of 7-
aryl-10,10-dimethyl-7,9,10,11-tetrahydro-9H-benzo[c]acridin-8-one derivatives from
the condensation of 1-naphthylamine, aldehydes, and dimedone under solvent-free
conditions at 120 ꢁC or in refluxing ethanol. Using solid acids as catalyst offers
advantages including simplicity of operation, easy workup, recycling of the catalyst,
and good yields of products.
EXPERIMENTAL
All the chemicals were purchased from Merck Company. Melting points were
measured by using the capillary tube method with an Electrothermal 9200 apparatus.
1H NMR spectra were recorded on a Bruker AQS Avance 500-MHz spectrometer
using tetramethylsilane (TMS) as an internal standard (CDCl3 solution). Infrared
(IR) spectra were recorded on the FT-IR Bruker Tensor 27 instrument. All products
were known compounds and identified by comparison of their spectral and physical
data with the literature description.[12,14,21] Yields were obtained using gas chromato-
graphic (GC) analysis.
General Procedure for the Synthesis of 7-Aryl-10,10-
dimethyl-7,9,10,11-tetra-hydro-9H-benzo[c]acridin-8-one
Derivatives Under Solvent-Free Conditions
A solution of an aromatic aldehyde (1 mmol), dimedone (1 mmol), 1-naphthyl-
amine (1 mmol), and NH2SO3H (10 mol%) or H6P2W18O62 ꢀ 18H2O (1 mol%) was
stirred at 120 ꢁC for an appropriate time. After completion of the reaction, which
was monitored by thin-layer chromatography (TLC), boiling ethanol was added
to the mixture. The catalyst was filtered off, and the mixture was cooled to room
temperature. The resulting solid product was then removed by filtration and purified
by column chromatography.
Recycling of NH2SO3H
After completion of the reaction, boiling ethanol was added to the mixture, and
the catalyst was recycled by simple filtration, washed with diethyl ether, dried at
80 ꢁC, and reused for the next reaction with only a modest loss in activity. The cata-
lyst was recovered and reused five times in the synthesis of 10,10-dimethyl-7-
(3-nitrophenyl)-7,9,10,11-tetrahydro-9H-benzo[c] acridin-8-one, and the obtained
results are summarized in Table 3.

SYNTHESIS OF BENZO[c]ACRIDINE DERIVATIVES
2037
10,10-Dimethyl-7-(3-nitrophenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4b)
IR (KBr) (nmax, cmꢂ1): 3303, 2956, 1664, 1589, 1526, 1494, 1386, 1347, 1259, 1150,
1092, 1030, 806, 758, 730 cmꢂ1; 1H NMR (DMSO-d , 500 MHz) dH (ppm): 0.98 (s, 3H,
6
CH3), 1.15 (s, 3H, CH3), 2.28 (d, J ¼ 16.47 Hz, 1H, C11H), 2.36 (d, J ¼ 16.32, 1H,
C11-H), 2.61 (d, J ¼ 16.6Hz, 1H, C9-H), 2.65 (d, J ¼ 16.15 Hz, 1H, C9-H), 5.57 (s,
1H, CH), 6.89 (s, 1H, NH), 7.23 (d, J ¼ 8.4 Hz, 1H, ArH), 7.4–7.43 (t, J ¼ 7.9, 1H,
ArH), 7.51–7.64 (m, 3H, ArH), 7.79 (d, J ¼ 7.7 Hz, 1H, ArH), 7.83 (d, J ¼ 8.56Hz,
1H, ArH), 7.86 (d, J ¼ 7.9, 1H, ArH), 7.98–8.1 (m, 2H, ArH); GC=MS: 398 (Mþ).
10,10-Dimethyl-7-(2-chlorophenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4c)
IR (KBr) (nmax, cmꢂ1): 3300, 2950, 2860, 1670, 1588, 1520, 1492, 1380, 1267,
1150, 1077, 1010, 751; 1H NMR (DMSO-d6, 500 MHz) dH (ppm): 1.03 (s, 3H,
CH3), 1.15 (s, 3H, CH3), 2.08 (d, J ¼ 16.4 Hz, 1H, C11-H), 2.22 (d, J ¼ 16.4 Hz,
1H, C11-H), 2.58 (d, J ¼ 16.8 Hz, 1H, C9-H), 2.79 (d, J ¼ 16.8 Hz, 1H, C9-H), 5.71
(s, 1H, CH), 7.09–7.65 (m, 8H, ArH), 7.88 (d, J ¼ 8.0 Hz, 1H, ArH), 8.42 (d,
J ¼ 8.4 Hz, 1H, ArH), 9.24 (s, 1H, NH). GC=MS: 386 (Mþ).
10,10-Dimethyl-7-(4-chlorophenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4d)
IR (KBr) (nmax, cmꢂ1): 3312, 2966, 1687, 1590, 1520, 1378, 1277, 1159, 1093, 1077,
1010, 859, 811, 762; 1H NMR (DMSO-d6, 500 MHz) dH (ppm): 0.99 (s, 3H, CH3), 1.09
(s, 3H, CH3), 2.09 (d, J ¼ 16.0 Hz, 1H, C11-H), 2.33 (d, J ¼ 16.0Hz, 1H, C11-H), 2.76 (d,
J ¼ 16.8Hz, 1H, C9-H), 2.75 (d, J ¼ 16.8Hz, 1H, C9-H), 5.233 (s, 1H, CH), 7.21–7.28
(m, 5H, ArH), 7.50–7.59 (m, 2H, ArH), 7.52–7.60 (m, 1H, ArH), 7.89 (d, J ¼ 8.4 Hz,
1H, ArH), 8.38 (d, J ¼ 8.4 Hz, 1H, ArH), 9.22 (s, 1H, NH); GC=MS: 386 (Mþ).
10,10-Dimethyl-7-(2,4-dichlorophenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4e)
IR (KBr) (nmax, cmꢂ1): 3321, 2966, 1681, 1589, 1521, 1487, 1471, 1388, 1260,
1
1155, 1102, 1057, 862, 810, 765, 730; H NMR (DMSO-d6, 500 MHz) dH (ppm):
1.04 (s, 3H, CH3), 1.15 (s, 3H, CH3), 2.08 (d, J ¼ 16.4 Hz, 1H, C11-H), 2.24 (d,
J ¼ 16.4 Hz, 1H, C11-H), 2.66 (d, J ¼ 16.6 Hz, 1H, C9-H), 2.78 (d, J ¼ 16.6 Hz, 1H,
C9-H), 5.80 (s, 1H, CH), 7.35 (d, J ¼ 8.4 Hz, 1H, ArH), 7.25–7.35 (m, 2H, ArH),
7.52 (d, J ¼ 8.0 Hz, 1H, ArH), 7.69–7.71 (m, 3H, ArH), 7.81 (d, J ¼ 7.6 Hz, 1H,
ArH), 8.55 (d, J ¼ 8.4 Hz, 1H, ArH), 9.36 (s, 1H, NH); GC=MS: 422 (Mþ).
10,10-Dimethyl-7-(4-hydroxylphenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4f)
IR (KBr) (nmax, cmꢂ1): 3298, 2966, 2922, 1670, 1569, 1523, 1458, 1474, 1398,
1268, 1174, 1147, 1110, 1071, 830, 758; 1H NMR (DMSO-d6, 500 MHz) dH

2038
M. M. HERAVI ET AL.
(ppm): 1.03 (s, 3H, CH3), 1.11 (s, 3H, CH3), 2.08 (d, J ¼ 16.0 Hz, 1H, C11-H), 2.33 (d,
J ¼ 16.0 Hz, 1H, C11-H), 2.65 (d, J ¼ 16.8 Hz, 1H, C9-H), 2.77 (d, J ¼ 16.8 Hz, 1H,
C9-H), 5.69 (s, 1H, CH), 6.78 (d, J ¼ 8.4 Hz, 2H, ArH), 6.99 (d, J ¼ 8.4 Hz, 2H,
ArH), 7.32 (d, J ¼ 8.4 Hz, 1H, ArH), 7.44–7.61 (m, 3H, ArH), 7.91 (d, J ¼ 7.6 Hz,
1H, ArH), 8.49 (d, J ¼ 8.4 Hz, 1H, ArH), 9.09 (s, 1H, OH), 9.207 (s, 1H, NH).
GC=MS: 368 (Mþ).
10,10-Dimethyl-7-(4-methoxylphenyl)-7,9,10,11-tetrahydro-9H-
benzo[c]acridin-8-one (4g)
IR (KBr) (nmax, cmꢂ1): 3309, 2988, 2877, 1680, 1589, 1520, 1488, 1433, 1377,
1
1269, 1188, 1150, 1029, 839, 811, 765, 750; H NMR (DMSO-d6, 500 MHz) dH
(ppm): 1.01 (s, 3H, CH3), 1.12 (s, 3H, CH3), 2.10 (d, J ¼ 16.4 Hz, 1H, C11-H), 2.35
(d, J ¼ 16.4 Hz, 1H, C11-H), 2.78 (d, J ¼ 16.6 Hz, 1H, C9-H), 2.73 (d, J ¼ 16.6 Hz,
1H, C9-H), 3.58 (s, 3H, CH3O), 5.20 (s, 1H, CH), 6.73 (d, J ¼ 8.4 Hz, 2H, ArH),
7.18 (d, J ¼ 8.4 Hz, 2H, ArH), 7.32 (d, J ¼ 8.0 Hz, 1H, ArH), 7.49–7.58 (m, 3H,
ArH), 7.66 (d, J ¼ 8.0 Hz, 1H, ArH), 8.32 (d, J ¼ 8.4 Hz, 1H, ArH), 9.09 (s, 1H,
NH). GC=MS: 382 (Mþ).
ACKNOWLEDGMENT
The authors are thankful to Azzahra Research Council for partial financial
support.
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