Novel synthesis of bis-iminocoumarins

Article abstract of DOI:10.1080/00397911.2010.531370

Reaction of 3-aryl iminocoumarins with diacid chlorides as C-electrophilic reagents under mild conditions novel bis-iminocoumarins in good yields. When the reaction was performed with alkylene dibromides by heating them in toluene in the presence of IRA 9

Full text of DOI:10.1080/00397911.2010.531370

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Novel Synthesis of Bis-Iminocoumarins
H. Ammar a , S. Abid a , Y. Le Bigot b & R. El Gharbi a
a Laboratoire de Chimie Appliquée: Hétérocycles, Corps Gras et
Polymères Faculté des Sciences, Sfax, Tunisia
b Laboratoire de Génie Chimique, ENSIACET, Toulouse, France
Available online: 24 Aug 2011
To cite this article: H. Ammar, S. Abid, Y. Le Bigot & R. El Gharbi (2012): Novel Synthesis of Bis-
Iminocoumarins, Synthetic Communications: An International Journal for Rapid Communication of
Synthetic Organic Chemistry, 42:6, 799-810
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Synthetic Communications1, 42: 799–810, 2012
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2010.531370
NOVEL SYNTHESIS OF BIS-IMINOCOUMARINS
H. Ammar,1 S. Abid,1 Y. Le Bigot,2 and R. El Gharbi1
1
´
Laboratoire de Chimie Appliquee: Heterocycles, Corps Gras et Polymeres
Faculte des Sciences, Sfax, Tunisia
´ ´
`
´
2
´
Laboratoire de Genie Chimique, ENSIACET, Toulouse, France
GRAPHICAL ABSTRACT
Abstract Reaction of 3-aryl iminocoumarins with diacid chlorides as C-electrophilic
reagents under mild conditions novel bis-iminocoumarins in good yields. When the reaction
was performed with alkylene dibromides by heating them in toluene in the presence of IRA
900 resin, bis-ether compounds were obtained by way opening the pyranic ring. The struc-
1
tures of the product obtained were characterized by Fourier transform infrared, H NMR,
13C NMR, and elemental analysis.
Keywords Bis-iminocoumarins; diacid chlorides; iminocoumarins; Knoevenagel
condensation
INTRODUCTION
In recent years, there has been increasing interest in 2H-1-benzopyran-2-imines
(also called iminocoumarins) regarding their potential broad-spectrum biological
activity,[1–3] their original optical properties,[4–6] and their considerable value in
synthetic organic chemistry as starting materials in formation of various polycyclic
compounds consisting of benzopyran fragments fused with different heterocyclic
rings.[7–10] In the latter context, a number of studies from our laboratory have
focused on the reactivity of 3-cyano iminocoumarins toward N-nucleophilic
reagents to obtain novel heterocyclic compounds such as benzopyranopyrimidines,
benzopyranopyrazoles, benzopyranoisoxazoles, and 3-triazolonyl iminocoumarins,
which could exhibit interesting biological activities.[11–14] Iminocoumarins also can
be substituted on their imino group by reaction with electrophilic reagents, thus
allowing a wide panel of compounds to be prepared.[15–17] We have reported that
ethylchloroformate, acid chlorides, organic isocyanates and semicarbazides, as
Received August 5, 2010.
Address correspondence to S. Abid, Laboratoire de Chimie Appliquee: Heterocycles, Corps Gras et
´ ´ ´
Polymeres, Faculte des Sciences de Sfax, 3000, Sfax, Tunisia. E-mail: abidsouhir@yahoo.fr
`
´
799

800
H. AMMAR ET AL.
C-electrophilic reagents, reacted easily with iminocoumarins, leading to novel
materials for applications based on their optical properties.[18–22]
As a continuation of this investigation aimed at modifying iminocoumarin
properties, we decided to study the synthesis of bifluorophoric molecules incorporat-
ing two iminocoumarin nuclei associated by their imidic groups. A literature survey
has revealed that this family of iminocoumarinic derivatives has received little
attention, whereas the coumarinic analogs occupy an interesting position in the
well-known family of coumarin derivatives. Bis-coumarins often possess interesting
pharmacological properties such as antimicrobial,[23] anticoagulant,[24] anti-
inflammatory,[25] cardiovascular,[26] and antiproliferative activities.[27] Their optical
properties are influenced by both the nature of coumarin fluorophore and the chemi-
cal structure of the bridge. Thus 3,30-p-phenylene bis-coumarins are of high interest
in the field of fluorescent dyes because they possess molar absorption coefficients
much greater than that of corresponding mono-coumarins and their quantum yields
are very high,[28] whereas bis-coumarins based on 7-(4-methylcoumarinyl) diesters
are not really interesting as fluorescent materials.[29]
Asimov et al.[30] were the first to envisage the synthesis of bifluorophore mole-
cules incorporating an iminocoumarinic fragment, which led to new high-efficiency
laser dyes consisting of coumarinic and iminocoumarinic fluorophores linked by
thiazolyl heterocycle as a bridge.[30] However, the process and the reaction mech-
anism were not tackled, and the compound characterization was relatively limited
because of the lack of complete spectroscopic assessment. As part of our program
directed toward the synthesis of bifluorophore compounds,[31,32] we reported a
new synthetic route to a series of bis-iminocoumarins involving the coupling of
two 3-aryl iminocoumarin units with aromatic diamines by Schmidt reaction cata-
lyzed by ion-exchange resins.[33]
The purpose of this study was the synthesis of new molecules bearing two imi-
nocoumarinic moieties linked by a diacyl bridge because of both their possible use as
fluorescent dyes and their potential therapeutical use.
RESULTS AND DISCUSSION
Iminocoumarins 1–3 were prepared using Knoevenagel condensation proce-
dures in one-pot reactions from 2-hydroxybenzaldehyde and arylacetonitriles in
the presence of basic resin Amberlite IRA 900 as catalyst. The spontaneous cycliza-
tion between the ortho hydroxy group and the side-chain cyano group led to the
corresponding iminocoumarin derivatives (Scheme 1) in good yields (recrystallized
1
from toluene). Their structures were assigned by infrared (IR), H and 13C NMR,
and elemental analysis.
The coupling of compounds 1–3 with diacid chlorides a–g led to bis-
iminocoumarins following the N-nucleophilic attack on acid chloride function
(Scheme 2).
Reaction of 1 þ e was selected as a model system for a thorough study aimed at
optimizing the bis-iminocoumarin yield. Various solvents were tested, ranging in
polarity and nucleophilic or electrophilic character from toluene to DMA, but no
major trend was observed within this large domain of media because yields varied
by only a few percentage points. Iminocoumarin 1 concentration was changed

SYNTHESIS OF NOVEL POLYCYCLIC COMPOUNDS
801
Scheme 1.
between 0.05 and 0.20 M, and this produced a considerable increase in bis-
iminocoumarin yield. With a 0.12 M solution of 1, the molar concentration of diacid
chloride e was varied from the stoichiometric value up to a molar excess of 30%.
Maximum yield was obtained with 20% excess, suggesting that a small amount of
COCl moieties had been hydrolyzed (the corresponding carboxylic acid function is
inactive in these systems). All the preliminary runs were conducted in the presence
of pyridine used in stoichiometric quantity with respect to the HCl generated in
the reaction. Triethylamine was also tested but gave less encouraging results. The
role of the reaction temperature was furthermore between 0 and 60 ꢀC. The most
adequate temperature was around 25 ꢀC. The reaction time required to attain the
optimal conversion was 5 h. With these conditions, yields were reproducibly close
to 97%. The application of the optimized conditions to various combinations
gave corresponding bis-iminocoumarins with good or moderate yields (Table 1).
The expected structures were clearly confirmed by the elemental analyses and the
spectroscopic studies.
We extended our study to the use of alkylene bromides as C-electrophile
reagents, but nucleophilic attack of imidic nitrogen on methylene groups did not
take place because detectable bis-iminocoumarins appeared when reacting 1 with
p-xylene dibromide, 1,4-dibromobut-2-ene, or 1,4-dibromobutane (Scheme 3). Thus
it might be expected that the relatively poor electrophilic character of methylene
groups did not allow their interaction with imidic nitrogen. To solve this problem,
the reaction was studied in the presence of IRA 900 resin as an appropriate basic
entity in the same conditions used for iminocoumarin 1 synthesis, but our attempts
failed. The reaction from h and i furnished novel products 1h and 1i, respectively, not
containing any benzopyrano fragments instead of the anticipated formation of
bis-iminocoumarins as shown in Scheme 3.
Scheme 2.

802
H. AMMAR ET AL.
Table 1. Synthesis of bis-iminocoumarins
Bis-iminocoumarins
Ar
A
Yields (%)
1a
1b
1c
1d
1e
1f
(CH2)0
(CH2)1
(CH2)2
(CH2)4
(CH2)8
p-Ph
55
62
70
89
97
90
86
57
61
80
89
80
67
83
92
86
1g
2b
2c
2d
2e
2g
3c
3d
3e
3f
o-Ph
(CH2)1
(CH2)2
(CH2)4
(CH2)8
o-Ph
(CH2)2
(CH2)4
(CH2)8
p-Ph
The elemental analysis and the spectral data of these two new compounds were
entirely consistent with the structures of 1h and 1i. In particular, the Fourier trans-
form infrared (FTIR) spectra showed an absorption band of CꢁN function, and in
the 1H NMR singlets from -O-CH2 fragments were observed. As shown in Scheme 4,
a mechanism involving two consecutive steps can be postulated to explain the forma-
tion of 1h and 1i. In the first step, acido-basic interaction of imino group with resin
functions takes place after opening the pyranic ring to give phenate ions. In the
second stage, an etherification reaction occurs to afford bis-ether compounds 1h
and 1i by O-nucleophilic attack of phenate ions on methylene groups.
Scheme 3.

SYNTHESIS OF NOVEL POLYCYCLIC COMPOUNDS
803
Scheme 4.
CONCLUSION
The reaction of 3-aryl iminocoumarins with diacid chlorides appears well suited
to the synthesis of bifluorophore compounds bearing two iminocoumarinic moieties.
These compounds were easily purified and obtained in good yields. In contrast, when
p-xylene dibromide or 1,4-dibromo but-2-ene were used as C-electrophile reagents, an
O-alkylation reaction took place, leading to bis-ether formation. Work is in progress
to assess the biological activities and the optical properties of these novel materials.
EXPERIMENTAL
2-Hydroxybenzaldehyde, nitriles, diacid chlorides, and dibromide compounds
are commercial products. Solvents (toluene, chloroform) were purified by standard
techniques and redistilled prior to their use. Catalyst IRA 900 was conditioned
and then used. The melting points were determined on an Electrothermal 9100
apparatus. IR spectra were obtained on a Jasco FT-IR 420 instrument using KBr
1
pellets. H and 13C NMR spectra were recorded on a Bruker WP 200 spectrometer
at 300 MHz and 75.0 MHz, respectively, in CDCl3 or dimethylsulfoxide (DMSO-d6),
with tetramethylsilane (TMS) as internal standard (chemical shifts in ppm). Elemen-
tal microanalysis were performed on an EA 1112 analyser from CE Instruments.
Mass spectra (MS) were recorded on a DSQII ThermoFisher spectrometer.
Synthesis of Iminocoumarins (1–3)
A mixture of 2-hydroxybenzaldehyde (20 mmol), IRA 900 resin (2 g, 20 mmol
OHꢂ), and toluene (25 mL) was introduced into a 250-mL, three-neck flask equipped
with a condenser and stirred for 3 h at 85 ꢀC under a nitrogen atmosphere. After that,
nitrile (20 mmol) was added, and the mixture was refluxed for 8 h. After completion of
the reaction, the organic phase was separated from the solid catalyst and concentrated
under reduced pressure. The solid phase was recrystallized from toluene.

804
H. AMMAR ET AL.
3-Phenyliminocoumarin (1). IR (KBr) (cmꢂ1): n ¼ 1644 (C N), 3275 (NH).
=
1H NMR (CDCl3) (ppm): d ¼ 7.02–7.21 (m, 2H, H6, H8), 7.85 (td, 1H, H7, J ¼ 7.9,
2.2 Hz), 7.92 (dd, 1H, H5, J ¼ 8.7, 2.2 Hz), 7.10–7.35 (m, 5H, HPh), 8.15 (s, 1H, H4),
8.60 (br, 1H, NH). 13C NMR (CDCl3) (ppm): d ¼ 156.9 (C2), 128.9 (C3), 138.6 (C4),
129.2 (C5), 123.6 (C6), 132.4 (C7), 116.1 (C8), 151.0 (C9), 119.3 (C10), 125.8, 127.9,
128.2, 129.4 (CPh). Mp (ꢀC) ¼ 105. Calculated for C15H11NO: C, 81.44; H, 4.97;
N, 6.33. Found: C, 81.52; H 5.01; N 6.44.
3-(p-nitrophenyl)iminocoumarin (2). IR (KBr) (cmꢂ1): n ¼ 1651 (C N),
=
1
3297 (NH). H NMR (DMSO-d6) (ppm): d ¼ 6.91–7.20 (m, 2H, H6, H8), 7.45 (td,
0
1H, H7, J ¼ 8.7, 2.1 Hz), 7.58 (dd, 1H, H5, J ¼ 8.4, 2.1 Hz), 7.93 (d, 2H, H2 p-NO2Ph
,
0
J ¼ 8.9 Hz), 8.32 (d, 2H, H3 p-NO2Ph, J ¼ 8.9 Hz), 8.23 (s, 1H, H4), 8.58 (br, 1H, NH).
13C NMR (DMSO-d6) (ppm): d ¼ 157.7 (C2), 127.2 (C3), 140.8 (C4), 128.4 (C5), 124.8
(C6), 133.7 (C7), 119.7 (C8), 153.5 (C9), 116.6 (C10), 108.0, 120.8, 130.5, 147.6
(Cp-NO2Ph). Mp (ꢀC) ¼ 182. Calculated for C15H10N2O3: C, 67.67; H, 3.76, N,
10.53. Found: C, 67.73, H, 3.81; N, 10.49.
3-(2-Thiophenyl)iminocoumarin (3). IR (KBr) (cmꢂ1): n ¼ 1649 (C N),
=
1
3276 (NH). H NMR (DMSO-d6) (ppm): d ¼ 7.04–7.18 (m, 2H, H6, H8), 7.72 (td,
0
1H, H7, J ¼ 8.1, 2.2 Hz), 7.90 (dd, 1H, H5, J ¼ 8.5, 2.2 Hz), 6.98 (dd, 1H, H4 Th
,
0
0
J ¼ 3.7, 4.9 Hz), 7.29 (dd, 1H, H3 Th, J ¼ 3.7, 0.9 Hz), 7.45 (dd, 1H, H5 Th, J ¼ 4.9,
0.9 Hz), 8.12 (s, 1H, H4), 8.60 (br, 1H, NH). 13C NMR (DMSO-d6) (ppm):
d ¼ 158.4 (C2), 130.9 (C3), 137.8 (C4), 128.0 (C5), 127.2 (C6), 136.9 (C7), 119.8
(C8), 152.6 (C9), 115.3 (C10), 123.7, 127.6, 130.4, 137.3 (CTh). Mp (ꢀC) ¼ 80. Calcu-
lated for C13H9NOS: C, 68.72, H, 3.96, N, 6.16. Found: C, 68.60; H, 3.87; N, 6.25.
Synthesis of Bis-Iminocoumarins
Diacid chloride (1.8 mmol) was slowly dropped into to a stirred mixture of imi-
nocoumarin (3 mmol) in 25 ml of chloroform, containing 3 mmol of pyridine at 0 ꢀC.
The mixture was stirred for 5 h at room temperature. A white solid was precipitated
from the reaction mixture and collected by filtration. The solid phase was recrystal-
lized from toluene (compound 1a– 1e, 2b–2e) or from ethyl acetate (compounds 1f,
1g, 2f, 2g, 3c–3f).

SYNTHESIS OF NOVEL POLYCYCLIC COMPOUNDS
805
1
Bis-iminocoumarin (1a). IR (KBr) (cmꢂ1): n ¼ 1633 (C N), 1703 (C O). H
NMR (CDCl3) (ppm): d ¼ 7.06–7.30 (m, 4H, H6, H8), 7.46 (td, 2H, H7, J ¼ 8.1,
2.1 Hz), 7.55 (dd, 2H, H5, J ¼ 8.7, 2.1 Hz), 7.62–7.70 (m, 10H, HPh), 8.26 (s, 2H,
H4). 13C NMR (CDCl3) (ppm): d ¼ 161.4 (C2), 127.6 (C3), 139.8 (C4), 128.7 (C5),
=
=
=
124.2 (C6), 132.4 (C7), 119.4 (C8), 154.3 (C9), 115.5 (C10), 171.5 (C O), 125.8,
126.1, 127.3, 129.4 (CPh). Mp (ꢀC) ¼ 185. Calculated for C32H20N2O4: C, 77.42; H,
4.03; N, 5.64. Found: C, 77.57; H, 3.95, N, 5.74.
1
Bis-iminocoumarin (1b). IR (KBr) (cmꢂ1): n ¼ 1665 (C N), 1713 (C O). H
NMR (CDCl3) (ppm): d ¼ 3.33 (s, 2H, CH2), 7.02–7.20 (m, 4H, H6, H8), 7.68 (td,
2H, H7, J ¼ 7.8, 2.3 Hz), 7.71 (dd, 2H, H5, J ¼ 8.4, 2.3 Hz), 7.36–7.56 (m, 10H,
=
=
H
Ph), 8.26 (s, 2H, H4). 13C NMR (CDCl3) (ppm): d ¼ 155.6 (C2), 128.3 (C3), 141.2
(C4), 128.5 (C5), 125.7 (C6), 133.0 (C7), 117.9 (C8), 151.5 (C9), 113.2 (C10), 169.1
(C O), 125.1, 126.3, 127.8, 129.3 (CPh), 59.2 (CH2). Mp (ꢀC) ¼ 130. Calculated for
=
C33H22N2O4: C, 77.64; H, 4.31; N, 5.49. Found: C, 77.72; H, 4.25; N, 5.60.
1
Bis-iminocoumarin (1c). IR (KBr) (cmꢂ1): n ¼ 1671 (C N), 1712 (C O). H
NMR (CDCl3) (ppm): d ¼ 3.02 (s, 4H, 2 ꢃ CH2), 7.00–7.23 (m, 4H, H6, H8), 7.53 (td,
2H, H7, J ¼ 8.2, 2.4 Hz), 7.64 (dd, 2H, H5, J ¼ 8.7, 2.4 Hz), 7.29–7.47 (m, 10H, HPh),
8.20 (s, 2H, H4). 13C NMR (CDCl3) (ppm): d ¼ 161.8 (C2), 128.5 (C3), 140.6 (C4),
=
=
=
128.2 (C5), 124.9 (C6), 132.3 (C7), 119.0 (C8), 152.4 (C9), 117.9 (C10), 172.3 (C O),
125.4, 126.9, 127.8, 128.9 (CPh), 48.1 (CH2). Mp (ꢀC) ¼ 210. Calculated for
C34H24N2O4: C, 77.86; H, 4.58; N, 5.34. Found: C, 77.95; H, 4.55; N, 5.27.
1
Bis-iminocoumarin (1d). IR (KBr) (cmꢂ1): n ¼ 1655 (C N), 1710 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.44 (t, 4H, 2 ꢃ CH2, J ¼ 8.6 Hz), 1.99 (t, 4H, 2 ꢃ CH2,
J ¼ 8.6 Hz), 6.69–7.09 (m, 4H, H6, H8), 7.64 (td, 2H, H7, J ¼ 8.2, 2.5 Hz), 7.71 (dd,
2H, H5, J ¼ 8.4, 2.5 Hz), 7.14–7.44 (m, 10H, HPh), 8.24 (s, 2H, H4). 13C NMR
(DMSO-d6) (ppm): d ¼ 158.9 (C2), 127.9 (C3), 142.1 (C4), 127.7 (C5), 125.3 (C6),
=
=
=
131.8 (C7), 118.4 (C8), 155.0 (C9), 116.7 (C10), 170.2 (C O), 125.1, 127.1, 128.6,
129.2 (CPh), 24.2 (CH2), 34.5 (CH2). Mp (ꢀC) ¼ 162. Calculated for C36H28N2O4:
C, 78.26; H, 5.07; N, 5.07. Found: C, 78.32; H, 5.13; N, 5.17.
1
Bis-iminocoumarin (1e). IR (KBr) (cmꢂ1): n ¼ 1648 (C N), 1700 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.20 (m, 8H, 4 ꢃ CH2), 1.44 (m, 4H, 2 ꢃ CH2), 2.00 (t,
2H, CH2, J ¼ 7.2 Hz), 2.15 (t, 2H, CH2, J ¼ 7.5 Hz), 7.24–7.44 (m, 14H, H6, H8, HPh),
7.59 (td, 2H, H7, J ¼ 8.4, 1.2 Hz), 7.76 (dd, 2H, H5, J ¼ 7.5, 1.2 Hz), 8.23 (s, 2H, H4).
13C NMR (DMSO-d6) (ppm): d ¼ 159.4 (C2), 128.1 (C3), 143.1 (C4), 127.9 (C5), 124.8
=
=
=
(C6), 132.1 (C7), 119.1 (C8), 154.5 (C9), 115.8 (C10), 172.0 (C O), 125.4, 126.8, 127.4,
129.7 (CPh), 24.1 (CH2), 28.3 (CH2), 29.9 (CH2), 34.1 (CH2). Mp (ꢀC) ¼ 70. Calcu-
lated for C40H36N2O4: C, 78.94; H, 5.92; N, 4.60. Found: C, 78.85; H, 6.03; N, 4.69.
Bis-iminocoumarin (1f). IR (KBr) (cmꢂ1): n ¼ 1673 (C N), 1722 (C O).
1H NMR (DMSO-d6) (ppm): d ¼ 7.00–7.18 (m, 4H, H6, H8), 7.50 (td, 2H, H7,
J ¼ 8.2, 1.8 Hz), 7.65 (dd, 2H, H5, J ¼ 7.2, 1.8 Hz), 7.30–7.46 (m, 10H, HPh), 8.21
(s, 2H, H4), 7.92 (s, 4H, Hp-Ph). 13C NMR (DMSO-d6) (ppm): d ¼ 164.1 (C2),
128.2 (C3), 141.8 (C4), 127.5 (C5), 124.9 (C6), 134.3 (C7), 119.2 (C8), 158.3 (C9),
=
=
=
116.4 (C10), 173.5 (C O), 125.3, 127.4, 128.3, 129.4 (CPh), 127.9, 133.4 (Cp-Ph).

806
H. AMMAR ET AL.
Mp (ꢀC) ¼ 230. Calculated for C38H24N2O4: C, 79.72; H, 4.20; N, 4.89. Found: C,
79.63; H, 4.30; N, 4.78.
1
Bis-iminocoumarin (1g). IR (KBr) (cmꢂ1): n ¼ 1662 (C N), 1720 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 7.21–7.49 (m, 14H, H6, H8, HPh), 7.55 (td, 2H, H7,
J ¼ 9.1, 2.4 Hz), 7.82 (dd, 2H, H5, J ¼ 8.5, 2.4 Hz), 8.01 (s, 2H, H4), 7.61–7.73 (m,
4H, Ho-Ph). 13C NMR (DMSO-d6) (ppm): d ¼ 168.7 (C2), 128.4 (C3), 140.1 (C4),
=
=
=
127.7 (C5), 124.2 (C6), 134.8 (C7), 118.9 (C8), 155.6 (C9), 115.7 (C10), 172.1 (C O),
125.5, 127.7, 128.6, 129.7 (CPh), 130.2, 133.5, 134.9 (Co-Ph). Mp (ꢀC) ¼ 179. Calcu-
lated for C38H24N2O4: C, 79.72; H, 4.20; N, 4.89. Found: C, 79.60; H, 4.31; N, 4.75.
Bis-iminocoumarin (2b). IR (KBr) (cmꢂ1): n ¼ 1652 (C N), 1709 (C O).
1H NMR (DMSO-d6) (ppm): d ¼ 3.40 (s, 2H, CH2), 7.00–7.22 (m, 4H, H6, H8),
7.58 (td, 2H, H7, J ¼ 9.2, 2.0 Hz), 7.76 (dd, 2H, H5, J ¼ 8.4, 2.0 Hz), 7.83 (d, 4H,
=
=
0
0
H
2 p-NO2Ph, J ¼ 9.0 Hz), 8.38 (d, 4H, H3 p-NO2Ph, J ¼ 9.0 Hz), 8.30 (s, 2H, H4). 13C
NMR (DMSO-d6) (ppm): d ¼ 159.3 (C2), 128.1 (C3), 142.5 (C4), 128.3 (C5), 125.9
=
(C6), 134.6 (C7), 119.6 (C8), 154.2 (C9), 116.4 (C10), 172.0 (C O), 109.5, 122.4,
131.5, 146.9 (Cp-NO2Ph), 57.3 (CH2). Mp (ꢀC) ¼ 145. Calculated for C33H20N4O8:
C, 66.00; H, 3.33; N, 9.33. Found: C, 66.11; H, 3.25; N, 9.44.
Bis-iminocoumarin (2c). IR (KBr) (cmꢂ1): n ¼ 1641 (C N), 1716 (C O).
1H NMR (DMSO-d6) (ppm): d ¼ 2.96 (s, 4H, 2 ꢃ CH2), 7.09–7.19 (m, 4H, H6,
H8), 7.63 (td, 2H, H7, J ¼ 8.1, 1.8 Hz), 7.75 (dd, 2H, H5, J ¼ 8.4, 1.8 Hz), 7.42 (d,
=
=
0
0
4H, H2 p-NO2Ph, J ¼ 9.0 Hz), 8.16 (d, 4H, H3 p-NO2Ph, J ¼ 9.0 Hz), 8.21(s, 2H, H4).
13C NMR (DMSO-d6) (ppm): d ¼ 161.3 (C2), 128.4 (C3), 141.9 (C4), 128.9 (C5),
=
125.1 (C6), 134.0 (C7), 119.2 (C8), 152.7 (C9), 117.5 (C10), 173.1 (C O), 108.1,
121.6, 133.0, 141.2 (Cp-NO2Ph), 48.0 (CH2). Mp (ꢀC) ¼ 222. Calculated for
C34H22N4O8: C, 66.45; H, 3.58; N, 9.12. Found: C, 66.57; H, 3.75; N, 9.28.
1
Bis-iminocoumarin (2d). IR (KBr) (cmꢂ1): n ¼ 1650 (C N), 1713 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.40 (t, 4H, 2 ꢃ CH2, J ¼ 9.2 Hz), 2.01 (t, 4H, 2 ꢃ CH2,
J ¼ 9.2 Hz), 6.98–7.19 (m, 4H, H6, H8), 7.48 (td, 2H, H7, J ¼ 9.2, 2.0 Hz), 7.69 (dd,
=
=
0
0
2H, H5, J ¼ 8.4, 2.0 Hz), 7.51 (d, 4H, H2 p-NO2Ph, J ¼ 7.8 Hz), 8.11 (d, 4H, H3 p-NO2Ph
,
J ¼ 7.8 Hz), 8.20(s, 2H, H4). 13C NMR (DMSO-d6) (ppm): d ¼ 155.5 (C2), 127.2 (C3),
142.3 (C4), 127.5 (C5), 124.2 (C6), 133.3 (C7), 119.2 (C8), 151.0 (C9), 115.1 (C10),
=
173.4 (C O), 108.2, 120.4, 132.1, 144.9 (Cp-NO2Ph), 24.6 (CH2), 34.7 (CH2). Mp
(ꢀC) ¼ 173. Calculated for C36H26N4O8: C, 67.29; H, 4.05; N, 8.72. Found: C,
67.40; H, 4.11; N, 8.82.
1
Bis-iminocoumarin (2e). IR (KBr) (cmꢂ1): n ¼ 1650 (C N), 1708 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.22 (m, 8H, 4 ꢃ CH2), 1.51 (m, 4H, 2 ꢃ CH2), 2.09 (t,
2H, CH2, J ¼ 7.4 Hz), 2.16 (t, 2H, CH2, J ¼ 7.2 Hz), 7.01–7.20 (m, 4H, H6, H8), 7.55
(td, 2H, H7, J ¼ 8.9, 2.2 Hz), 7.64 (dd, 2H, H5, J ¼ 8.3, 2.2 Hz), 7.72 (d, 4H,
=
=
2 p-NO2Ph, J ¼ 7.8 Hz), 8.13 (d, 4H, H3 p-NO2Ph, J ¼ 7.8 Hz), 8.20 (s, 2H, H4). 13C
0
0
H
NMR (DMSO-d6) (ppm): d ¼ 159.3 (C2), 127.0 (C3), 141.9 (C4), 127.4 (C5), 124.7
=
(C6), 134.2 (C7), 118.4 (C8), 153.4 (C9), 116.8 (C10), 171.3 (C O), 109.8, 121.5,
133.5, 145.6 (Cp-NO2Ph), 24.3 (CH2), 29.0 (CH2), 30.2 (CH2), 35.2 (CH2). Calculated
for C40H34N4O8: C, 68.76; H, 4.87; N, 8.02. Found: C, 68.65; H, 5.00; N, 8.10.

SYNTHESIS OF NOVEL POLYCYCLIC COMPOUNDS
807
Bis-iminocoumarin (2g). IR (KBr) (cmꢂ1): n ¼ 1654 (C N), 1725 (C O).
=
=
1H NMR (DMSO-d6) (ppm): d ¼ 7.12–7.20 (m, 4H, H6, H8), 7.51 (td, 2H, H7,
0
J ¼ 7.2, 2.0 Hz), 7.77 (dd, 2H, H5, J ¼ 8.1, 2.0 Hz), 7.66 (d, 4H, H2 p-NO2Ph
,
0
J ¼ 9.3 Hz), 8.27 (d, 4H, H3 p-NO2Ph, J ¼ 9.3 Hz), 8.19 (s, 1H, H4), 7.54–7.62 (m, 4H,
H
o-Ph). 13C NMR (DMSO-d6) (ppm): d ¼ 163.4 (C2), 128.1 (C3), 142.5 (C4), 127.1
=
(C5), 124.6 (C6), 135.8 (C7), 117.2 (C8), 153.6 (C9), 113.9 (C10), 170.9 (C O),
108.8, 122.1, 130.5, 142.6 (Cp-NO2Ph), 131.2, 134.5, 135.2 (Co-Ph). Mp (ꢀC) ¼ 186. Cal-
culated for C38H22N4O8: C, 68.88; H, 3.32; N, 8.46. Found: C, 68.99; H, 3.21; N, 8.55.
1
Bis-iminocoumarin (3c). IR (KBr) (cmꢂ1): n ¼ 1664 (C N), 1710 (C O). H
=
=
NMR (DMSO-d6) (ppm): d ¼ 2.86 (s, 4H, 2 ꢃ CH2), 7.01–7.21 (m, 4H, H6, H8), 7.65
0
(td, 2H, H7, J ¼ 9.1, 2.0 Hz), 7.94 (dd, 2H, H5, J ¼ 8.7, 2.0 Hz), 6.91 (dd, 2H, H4 Th
,
0
0
J ¼ 4.1, 5.6 Hz), 7.32 (dd, 2H, H3 Th, J ¼ 4.1, 1.2 Hz), 7.49 (dd, 2H, H5 Th, J ¼ 5.6,
1.2 Hz), 8.22 (s, 2H, H4). 13C NMR (DMSO-d6) (ppm): d ¼ 161.8 (C2), 130.8 (C3),
137.8 (C4), 128.3 (C5), 127.2 (C6), 137.5 (C7), 119.2 (C8), 152.6 (C9), 115.7 (C10),
170.9 (C O), 123.9, 127.5, 131.9, 138.3 (CTh), 49.9 (CH2). Mp (ꢀC) ¼ 214. Calculated
=
for C30H20N2O4S2: C, 67.16; H, 3.73; N, 5.22. Found: C, 67.25; H, 3.65; N, 5.33.
1
Bis-iminocoumarin (3d). IR (KBr) (cmꢂ1): n ¼ 1647 (C N), 1716 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.42 (t, 4H, 2 ꢃ CH2, J ¼ 7.9 Hz), 2.08 (t, 4H, 2 ꢃ CH2,
J ¼ 7.9 Hz), 6.94–7.21 (m, 4H, H6, H8), 7.61 (td, 2H, H7, J ¼ 9.3, 2.4 Hz), 7.82 (dd,
=
=
0
0
2H, H5, J ¼ 8.7, 2.4 Hz), 6.83 (dd, 2H, H4 Th, J ¼ 3.7, 5.7 Hz), 7.32 (dd, 2H, H3 Th
,
J ¼ 3.7, 1.1 Hz), 7.52 (dd, 2H, H5 Th, J ¼ 5.7, 1.1 Hz), 8.19 (s, 2H, H4). 13C NMR
0
(DMSO-d6) (ppm): d ¼ 162.4 (C2), 131.5 (C3), 147.7 (C4), 127.4 (C5), 126.1 (C6),
=
130.6 (C7), 119.8 (C8), 153.1 (C9), 117.0 (C10), 172.4 (C O), 124.3, 127.7, 132.5,
139.0 (CTh), 24.1 (CH2), 37.2 (CH2). Mp (ꢀC) ¼ 170. Calculated for C32H24N2O4S2:
C, 68.08; H, 4.26; N, 4.96. Found: C, 68.24; H, 4.40; N, 5.13.
1
Bis-iminocoumarin (3e). IR (KBr) (cmꢂ1): n ¼ 1650 (C N), 1712 (C O). H
NMR (DMSO-d6) (ppm): d ¼ 1.28 (m, 8H, 4 ꢃ CH2), 1.63 (m, 4H, 2 ꢃ CH2), 2.11 (t,
2H, CH2 J ¼ 9.4 Hz), 2.27 (t, 2H, CH2 J ¼ 8.5 Hz), 7.20–7.29 (m, 4H, H6, H8), 7.33
(td, 2H, H7, J ¼ 9.3, 2.4 Hz), 7.72 (dd, 2H, H5, J ¼ 8.7, 2.4 Hz), 7.11 (dd, 2H,
=
=
0
0
0
H
4 Th, J ¼ 3.7, 5.7 Hz), 7.41 (dd, 2H, H3 Th, J ¼ 3.7, 1.1 Hz), 7.59 (dd, 2H, H5 Th
,
J ¼ 5.7, 1.1 Hz), 8.20 (s, 1H, H4). 13C NMR (DMSO-d6) (ppm): d ¼ 159.4 (C2),
133.4 (C3), 147.8 (C4), 127.5 (C5), 126.7 (C6), 130.9 (C7), 119.2 (C8), 151.2 (C9),
=
117.4 (C10), 170.2 (C O), 125.1, 126.4, 132.1, 138.7 (CTh), 24.1 (CH2), 28.8 (CH2),
29.5 (CH2), 34.7 (CH2). Mp (ꢀC) ¼ 77. Calculated for C36H32N2O4S2: C, 69.67; H,
5.16; N, 4.51. Found: C, 69.48; H, 5.10; N, 4.42.
1
Bis-iminocoumarin (3f). IR (KBr) (cmꢂ1): n ¼ 1670 (C N), 1723 (C O). H
=
=
NMR (DMSO-d6) (ppm): d ¼ 7.01–7.14 (m, 4H, H6, H8), 7.36 (td, 2H, H7, J ¼ 7.8,
0
1.9 Hz), 7.45 (dd, 2H, H5, J ¼ 7.3, 1.9 Hz), 6.86 (dd, 2H, H4 Th, J ¼ 4.2, 4.8 Hz),
0
0
7.36 (dd, 2H, H3 Th, J ¼ 4.2, 1.3 Hz), 7.58 (dd, 2H, H5 Th, J ¼ 4.8, 1.3 Hz), 8.22 (s,
2H, H4), 7.98 (s, 4H, Hp-Ph). 13C NMR (DMSO-d6) (ppm): d ¼ 161.5 (C2), 128.9
(C3), 143.2 (C4), 127.3 (C5), 124.2 (C6), 134.7 (C7), 119.0 (C8), 155.1 (C9), 115.9
=
(C10), 172.4 (C O), 125.1, 128.2, 131.5, 139.2 (CTh), 127.6, 134.3 (Cp-Ph). Mp
(ꢀC) ¼ 222. Calculated for C34H20N2O4S2: C, 69.86; H, 3.42; N, 4.79. Found: C,
69.74; H, 3.55; N, 4.60.

808
H. AMMAR ET AL.
Compound (1h). Yield 45%. IR (KBr) (cmꢂ1): n ¼ 1590 (C C), 2200 (CꢁN).
=
1H NMR (CDCl3) (ppm): d ¼ 5.16 (s, 4H, H15), 6.98 (dd, 2H, H8, J ¼ 8.3, 1.9 Hz),
7.08 (td, 2H, H14, J ¼ 8.9, 2.2 Hz), 7.27–7.34 (m, 10H, H6;H12;H13), 7.42 (s, 4H,
H17), 7.65 (td, 2H, H7, J ¼ 8.3, 1.7 Hz), 8.00 (s, 2H, H4), 8.17 (dd, 2H, H5, J ¼ 7.7,
1.7 Hz).13C NMR (CDCl3) (ppm): d ¼ 118.0 (CꢁN), 121.4 (C3), 137.3 (C4), 131.8
(C5), 121.3 (C6), 136.4 (C7), 112.4 (C8), 156.9 (C9), 111.9 (C10), 123.5, 126.0, 128.7,
128.9 (C11-14), 70.3 (C15), 134.6 (C16), 127.5 (C17). Mp (ꢀC) ¼ 183. MS m=z: 544
(4), 324 (45), 220 (100), 104 (80). Calculated for C38H28N2O2: C, 83.82; H, 5.15;
N, 5.15. Found: C, 83.92; H, 5.06; N, 5.26.
Compound (1i). Yield 38%. IR (KBr) (cmꢂ1): n ¼ 1610 (C C), 2209 (CꢁN).
=
1H NMR (CDCl3) (ppm): d ¼ 4.87 (d, 4H, H15, J ¼ 7.5), 6.22 (t, 2H, H16, J ¼ 7.5),
7.02 (dd, 2H, H8, J ¼ 8.7, 2.1 Hz), 7.11 (td, 2H, H14, J ¼ 9.1, 2.4 Hz), 7.35-7.54 (m,
10H, H6;H12;H13), 7.70 (td, 2H, H7, J ¼ 8.7, 1.9 Hz), 8.10 (s, 2H, H4), 8.15 (dd,
2H, H5, J ¼ 7.9, 1.9 Hz). 13C NMR (CDCl3) (ppm): d ¼ 118.5 (CꢁN), 121.4 (C3),
137.8 (C4), 136.9 (C5), 122.0 (C6), 134.0 (C7), 112.6 (C8), 157.5 (C9), 112.5 (C10),
125.9, 127.3, 128.5, 129.0 (C11-14), 66.8 (C15), 132.1 (C16). Mp (ꢀC) ¼ 145. MS m=z:
494 (4), 258 (53), 220 (100), 143 (76). Calculated for C34H26N2O2: C, 82.59; H,
5.26; N, 5.67. Found: C, 82.70; H, 5.14; N, 5.60.
ACKNOWLEDGMENT
The authors acknowledge the Ministry of Higher Education, Scientific
Research, and Technology in Tunisia for financial support.
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