Facile synthesis of imidazoisoindolones and quinoxalinediones from 2,3-diamino-1,4-naphthoquinone

Article abstract of DOI:10.3184/174751911X13001124874111

In aqueous acetic acid, 2,3-diamino-1,4-naphthoquinone reacted with phthalic anhydride and 4,5,6,7-tetrabromophthalic anhydride to give naphtho[2′,3′:4,5]imidazo[2,1-a]isoindole-6,11,13-triones. In the same solvent, the reaction of diaminonaphthoquinone with 2,2-dihydroxy-1H- indene-1,3(2H)-dione gave 11H-benzo[g]indeno [1,2-b]quinoxaline-6, 11, 13-trione. Under the same conditions, diaminonaphthoquinone reacted with succinic anhydride and with maleic anhydride, the corresponding 4-(3-amino-1,4-dioxo-1,4-dihydronaphthalene-2-ylamino)-4-oxobutanoic acid and 3,5,10-trioxo-3,4,5,10-tetrahydrobenzo[g]-quinoxaline-2(1H)-ylidene-acetic acid derivatives were obtained. The reaction of 2,3-diamino-1,4-naphthoquinone with (E)-1,2-dibenzoylethylene and 1,4-diphenylbut-2-yne-1,4-dione in aqueous acetic acid afforded dihydrobenzo[g]quinoxaline-5,10-diones.

Full text of DOI:10.3184/174751911X13001124874111

JOURNAL OF CHEMICAL RESEARCH 2011
RESEARCH PAPER 205
APRIL, 205–208
Facile synthesis of imidazoisoindolones and quinoxalinediones from
2,3-diamino-1,4-naphthoquinone
Ashraf A. Alya,b
aCurrent address: Chemistry Department, College of Science, Al-Jouf University, Sakaka, KSA
bChemistry Department, Faculty of Science, El-Minia University, 61519-El-Minia, Egypt
In aqueous acetic acid, 2,3-diamino-1,4-naphthoquinone reacted with phthalic anhydride and 4,5,6,7-
tetrabromophthalic anhydride to give naphtho[2’,3’:4,5]imidazo[2,1-a]isoindole-6,11,13-triones. In the same solvent,
the reaction of diaminonaphthoquinone with 2,2-dihydroxy-1H-indene-1,3(2H)-dione gave 11H-benzo[g]indeno
[1,2-b]quinoxaline-6,11,13-trione. Under the same conditions, diaminonaphthoquinone reacted with succinic anhy-
dride and with maleic anhydride, the corresponding 4-(3-amino-1,4-dioxo-1,4-dihydronaphthalene-2-ylamino)-
4-oxobutanoic acid and 3,5,10-trioxo-3,4,5,10-tetrahydrobenzo[g]-quinoxaline-2(1H)-ylidene-acetic acid derivatives
were obtained. The reaction of 2,3-diamino-1,4-naphthoquinone with (E)-1,2-dibenzoylethylene and 1,4-
diphenylbut-2-yne-1,4-dione in aqueous acetic acid afforded dihydrobenzo[g]quinoxaline-5,10-diones.
Keywords: 2,3-diamino-1,4-naphthoquinone, aqueous acetic acid, imidazoisoindolones and benzoquinoxalinediones
Naphthoquinones are widely distributed in plants, fungi and
some animals. Their biological activities have been studied
including their effects on prokaryotic and eukaryotic cells.1–4
Heterocyclic compounds containing the quinone group repre-
sent an important class of biologically active molecules.5
In vitro assays showed that several 2,3-disubstituted 1,4-
naphthoquinones are as effective as the clinically used anti-
fungal drugs fluconazole and amphotericin-B.6–8 It was also
reported that 2-amino-1,4-naphthoquinone showed promising
antimalarial activity in the bioassay.9,10 It is well-known that
liquid acetic acid is a hydrophilic (polar) protic solvent, similar
to ethanol and water. Acetic acid is also known significantly to
accelerate the reaction rate of some oxidation and cycloaddi-
tion reactions.11,12 Previously, Aly and his group13 investigated
the reaction of 1,8-diaminonaphthalene (as a structure analo-
gous to 2,3-diamino-1,4-naphthoquinone) with π-acceptors.
Aly et al.14 have also recently reported that imidazoles derived
from 2,3-diamino-1,4-naphthoquinone were easily directly
prepared by addition of the appropriate aldehydes in dimethyl
sulfoxide as a solvent. The effect of imidazo–isoindole deriva-
tives (mazindol) upon motor and feeding activity, two different
avoidance behaviors have been compared with those of δ-
amphetamine in rats. It was found that both drugs depress
feeding activity in a dose-related manner and increase the
motor activity of the animals.15 Indenoquinoxaline derivatives
are important classes of nitrogen containing heterocycles; they
have applications in dyes, are useful intermediates in organic
synthesis and have also been used as building blocks for the
synthesis of organic semiconductors.16,17 Focal microinjection
of benzoquinoxalines are used as an antagonist of the AMPA/
kainate subclass of glutamate receptors, and reduce neurologi-
cal deficits and tissue loss after spinal cord injury.18 Thus I now
report the synthesis of heterocyclic compounds from 2,3-
diamino-1,4-naphthoquinone, which may have a prospective
biological activity.
in 94% yield (Scheme 1). The mass spectrum and elemental
analysis of 3b confirmed its chemical formula as
C18H4Br4N2O3.
In warm aqueous acetic acid, the reaction of 2,3-diamino-
1,4-naphthoquinone (1) with 2,2-dihydroxy-1H-indene-
1,3(2H)-dione (ninhydrin, 4) yielded 11H-benzo[g]indeno[1,2-
b]quinoxaline-6,11,13-trione (5) in 90% yield (Scheme 1).
Under similar conditions and in aqueous acetic acid, reac-
tion of 1 with succinic anhydride (6) and at room temperature,
chromatographic purification produced 4-(3-amino-1,4-dioxo-
1,4-dihydronaphthalene-2-ylamino)-4-oxobutanoic acid (7) in
85% yields (Scheme 1).
The structural proof of 7 was based upon the mass, 1H NMR,
13C NMR and IR spectra as well as elemental analysis. Inter-
estingly, under reflux conditions the cyclisation process did
not occur.
Surprisingly, reaction of 1 with maleic anhydride (8) in
aqueous acetic acid and at room temperature afforded 3,4,5,10-
tetrahydro-3,5,10-trioxo-3,4-dihydrobenzo[g]quinoxaline-
2(1H)-ylidene-acetic acid (9) in 80% yields (Scheme 1). The
1
structural proof of 9 was based upon the mass, H NMR, 13C
NMR and IR spectra as well as elemental analysis.
In order to explore another mode of synthesis of quinoxa-
line, we reacted compound 1 with (E)-1,2-dibenzoylethylene
(10) in 95% acetic acid, After chromatographic purification,
2-(2-oxo-2-phenylethyl)-3-phenyl-1,2-dihydrobenzo[g]quino
xaline-5,10-dione (11) was obtained in 90% yield (Scheme 1).
The structural proof of 11 was based upon the mass, 1H NMR,
13C NMR and IR spectra as well as elemental analyses. MM2
calculations20 indicate that the Z-form of compound 11 has a
minimum energy compared with the E-form. That may be
related to the proposed forming hydrogen bond between the
benzoyl-CO and quinoxaline-NH (Fig. 1).
Interestingly, and in aqueous acetic acid (95%), a mixture of
compound 1 with 1,4-diphenylbut-2-yne-1,4-dione (13) was
refluxed and the reaction produced compound 14 (82% yield,
Scheme 1). On the basis of IR, MS, NMR spectra and elemen-
tal analysis, compound 14 was identified as (Z)-2-oxo-phenyl-
ethylidene)-3-phenyl-1,2-dihydrobenzo[g]quinoxaline-
5,10-dione. The disappearance of the absorption of the CH2
protons and the existence of the ethylenic-CH indicated that
compound 14 is the oxidised form of 11 which is consistent
with the foregoing. In compound 14, the ethylenic-CH
appeared at δ = 6.65 which gives HMBC correlation with the
ethylenic-C (δ = 139.2). Investigation of the HMBC correla-
tions indicated that the Z-form of compound 14 (Scheme 1). In
order to establish the structure of 14, we oxidised compound
11 by refluxing it with 2,3-dichloro-5,6-dicyano-1,4-benzo-
quinone (DDQ, 12) in toluene. The compound obtained has
identical physical and spectral data of those of compound 14.
Results and discussion
The investigation began by examining the reaction of a
mixture of 2,3-diamino-1,4-naphthoquinone (1) and phthalic
anhydride (2a) in aqueous acetic acid (70%). The reaction
afforded after chromatographic purification naphtho[2′,3′:4,5]
imidazo[2,1-a]isoindole-6,11,13-trione (3a)19 (there are no
published analytical nor physical data) in 75% yield
(Scheme 1). Similarly, reaction of 1 with 4,5,6,7-tetrabro-
mophthalic anhydride (2b) afforded 1,2,3,4-tetrabromo-
naphtho[2′,3′:4,5]imidazo[2,1-a]isoindole-6,11,13-trione (3b)
* Correspondent. E-mail: ashrafaly63@yahoo.com

206 JOURNAL OF CHEMICAL RESEARCH 2011
Scheme 1 Reactions of 2,3-diamino-1,4-naphthoquinone (1) with 2, 4, 6, 8, 10 and 13.
measured using gated decoupling. Correlations were established using
1H-1H COSY and HMBC experiments. Mass spectral data were
recorded on Varian MAT 312 instrument in EI mode (70 eV). Elemen-
tal analyses were carried out using Varian El Elementary.
Compound 1 was prepared according to the literature.21,22 Com-
pounds 2a,b, 4, 6, 8, 10 and 12 were purchased from Aldrich.
1,4-Diphenylbut-2-yne-1,4-dione (13) was prepared according to
literature.23
It is noteworthy in this context to mention that our attempts
failed to carry out the reactions of 2,3-diamino-1,4-
naphthoquinone with the reagents mentioned in Scheme 1
using solvents such as DMF, DMSO and toluene (see
Experimental).
Experimental
TLC was performed on analytical Merck 9385 silica aluminum sheets
(Kieselgel 60) with PF254 indicator. TLCs were viewed under ν =
254 nm UV. Melting points were determined on a Stuart electrother-
mal melting point apparatus and are uncorrected. IR spectra were
recorded as KBr disks on a Shimadzu-408 IR spectrophotometer.
NMR spectra were measured in CDCl3 and DMSO-d6, at 400 MHz
Reaction of 2,3-diaminonaphthoquinone (1) with phthalic anhydride
(2a) and/or 4,5,6,7-tetrabromophthalic anhydride (2b)
A solution of 1 (188 mg, 1 mmol) in aqueous acetic acid (30 mL, 70%,
v:v, 70 mL glacial acetic acid: 100 mL H2O) was added to a solution
of 2a,b (1 mmol) in in aqueous acetic acid (20 mL), and the reaction
mixture was stirred for 1h at room temperature and under reflux for
12–18 h. The reaction was followed by TLC analysis. The solvent of
1
for H and 100 MHz for 13C, using a Bruker AV-400 spectrometer.
Coupling constants are given in Hz; 1H-coupled 13C spectra were

JOURNAL OF CHEMICAL RESEARCH 2011 207
Fig. 1 Distinctive carbon signals in 13C NMR spectral data of compounds 5, 7, 9, 11 and 14.
the reaction mixture was removed under vacuum. The obtained resi-
due was applied on plate chromatography (silica gel: toluene: ethyl
acetate: 5:1) in case of purification of compound 3a and (silica gel:
toluene: ethyl acetate: 5:2) in case of purification of compound 3b.
Naphtho[2’,3’:4,5]imidazo[2,1-a]isoindole-6,11,13-trione (3a):
Yield 225 mg (75%), IR (KBr): ν = 2090–3020 (ArH), 1705–1690
Reaction of 1 with succinic anhydride (6) and maleic anhydride (8)
By applying the same procedure as above, a solution of 1 (188 mg,
1 mmol) in aqueous acetic acid (70%, 30 mL) was added to a solution
of 6 and/or 8 (1 mmol) in in aqueous acetic acid (70%, 10 mL),
and the reaction mixture was stirred for 18–24 h at room temp. The
reaction was followed by TLC analysis. The solvent of the reaction
mixture was removed under vacuum. The obtained residue was applied
on plate chromatography (silica gel: toluene: ethyl acetate: 5:1) in
case of purification of compound 7 and (silica gel: toluene) in case of
purification of compound 9.
4-(3-Amino-1,4-dioxo-1,4-dihydronaphthalene-2-ylamino)-4-
oxobutanoic acid (7): Yield 245 mg (85%), orange crystals (ethanol),
m.p. 230–232 °C (dec.). IR (KBr): ν = 3540–3340 (COOH, NH2, NH),
2090–3020 (aliph.-CH), 1720-1685 (CO), 1590 (C=C). 1H NMR
(400.134 MHz, CDCl3): δ = 12.30 (br, s, 1H, COOH), 9.10 (br, s, 1H,
NH), 4.75 (br, s, 2H, NH2), 8.05–7.96 (2H), 7.72–7.68 (2H), 2.80–
2.76, 7.72–7.68, 2.65–2.63 and 2.40–2.46 (dd, 4H, J = 7.9 Hz) ppm.
13C NMR (100.6 MHz, CDCl3): see Fig. 1. MS (70 eV, EI), m/z (%):
288 [M+] (100), 244 [M-CO2+] (40), 230 (30), 202 (24), 172 (20), 158
(34), 104 (42), 76 (38). Anal. Calcd for C14H12N2O5 (288.26): C, 58.33;
H, 4.20; N, 9.72. Found: C, 58.20; H, 4.02; N, 9.60%.
1
(CO), 1600 (C=N), 1590 (C=C). H NMR (400.134 MHz, CDCl3):
δ = 8.10–7.94 (m, 2H), 7.80–7.70 (m, 4H), 7.20–7.15 (m, 2H) ppm.
13C NMR (100.6 MHz, CDCl3): δ = 188.7, 180.4, 179.7 (CO), 156.5
(C=N), 137.2, 136.4 (naphtho-C=C), 134.0, 133.2, 132.0, 131.6
(ArC), 130.8, 130.2, 129.6, 128.4, 127.6, 127.0, 126.6, 126.2 (ArCH)
ppm. MS (70 eV, EI), m/z (%): 300 [M+] (100), 196 [M-PhCO+] (35),
190 (72), 172 (24), 158 (25), 104 (40), 79 (32). Anal. Calcd for
C18H8N2O3 (300.27): C, 72.00; H, 2.69; N, 9.33. Found: C, 72.14;
H, 2.80; N, 9.22%.
1,2,3,4-Tetrabromonaphtho[2’,3’:4,5]imidazo[2,1-a]isoindole-6,11,13-
trione (3b): Yield 578 mg (94%), orange crystals (methanol), m.p.
> 360 °C. 2098–3030 (ArH), 1708–1686 (CO), 1610 (C=N), 1592
1
(C=C). H NMR (400.134 MHz, DMSO-d6): δ = 8.00–7.95 (m, 2H)
and 7.15–7.12 (m, 2H) ppm. 13C NMR (100.6 MHz, DMSO-d6):
δ = 190.0, 179.0, 178.2 (CO), 155.5 (C=N), 142.0, 140.8 (4-Br-ArC),
134.0, 133.2 (naphtho-C=C), 131.2, 131.0 (ArC), 130.8 (Br-ArC),
130.2, 130.0, 128.0, 127.2, 127.6, 126.2, 126.0 ppm. MS (70 eV, EI),
m/z (%): 620 (3), 617 [M+1] (48), 616 (100), 615 (4), 612 (18), 533
(12), 456 (20), 454 (18), 378 (16), 376 (12), 300 (22), 298 (16), 198
(22), 196 (38), 192 (42), 190 (28), 172 (58), 130 (24), 106 (38), 104
(24), 76 (30). Anal. Calcd for C18H4Br4N2O3 (615.85): C, 35.10;
H, 0.65; Br, 51.90; N, 4.55. Found: C, 35.00; H, 0.75; Br, 51.80;
N, 4.42.
3,5,10-Trioxo-3,4,5,10-tetrahydrobenzo[g]quinoxaline-2(1H)
ylideneacetic acid (9):Yield 227 mg (80%), yellow crystals (ethanol),
m.p. 288–290 °C. IR (KBr): ν = 3530–3320 cm−1, (NH,OH), 3020–
1
2090 (ArH), 1720–1685 (CO), 1600 (C=N), 1590 (C=C). H NMR
(400.134 MHz, CDCl3): δ = 12.40 (br, s, 1H, COOH), 8.30 (br, s, 1H,
NH), 8.10–7.96 (m, 2H), 7.50–7.40 (m, 2H), 6.30 (br, s, 1H, NHCO),
6.00 (s, 1H, vinylic-H) ppm. 13C NMR (100.6 MHz, CDCl3): δ =
188.7, 180.4, 179.7 (CO), 156.5 (C=N), 137.2, 136.4 (C=C), 134.0,
133.2, 132.0, 131.6 (ArC), 130.8, 130.2, 129.6, 128.4, 127.6, 127.0,
126.6, 126.2 (ArCH) ppm. MS (70 eV, EI), m/z (%): 284 [M+] (100),
196 [M-PhCO+] (35), 190 (72), 172 (24), 158 (25), 104 (40), 79 (32).
Anal. Calcd for C14H8N2O5 (284.22): C, 59.16; H, 2.84; N, 9.86.
Found: C, 59.04; H, 2.80; N, 9.77%.
Reaction of 1 with 2,2-dihydroxy-1H-indene-1,3(2H)-dione (4)
A mixture of 1 (188 mg, 1 mmol) and 4 (0.178 mg, 1 mmol) in aque-
ous acetic acid (70%, 100 mL), was warmed at 40–60 °C for 10 h. The
solvent of the reaction mixture was concentrated to its half volume
and the formed product 5 was filtered and washed with diluted ethanol
(50%, 100 mL).
Reaction of compound 1 with (E)-1,2-benzoylethylene (10) and 1,4-
diphenyl-but-2-yne-1,4-dione (13)
13H-Benzo[g]indeno[1,2-b]quinoxaline-6,11,13-trione (5): Yield
281 mg (90%), yellowish green crystals (ethanol), m.p. 340 °C (dec.).
IR (KBr): ν = 3090-3040 (ArCH), 1723, 1690–1680 (CO), 1590
(C=N), 1578 (C=C). 1H NMR (400.134 MHz, DMSO-d6): δ = 8.32–
8.27 (m, 2H, H-8,9), 8.18–8.15 (dd, 1H, J = 8.1, 1.2 Hz, H-1), 8.04–
8.00 (m, 2H, H-7,10), 7.89–7.85 (m, 2H, H-3,4), 7.80–7.76 (m, 1H,
H-2).- 13C NMR (100.6 MHz, DMSO-d6): Fig. 1. MS (70 eV, EI), m/z
(%): 312 [M+] (100), 248 (58), 256 (26), 228 (40), 202 (12), 154 (14),
126 (16), 104 (36), 76 (22). Anal. Calcd for C19H8N2O3 (312.28):
C, 73.08; H, 2.58; N, 8.97. Found: C, 73.18; H, 2.55; N, 8.84%.
A mixture of 1 (188 mg, 1 mmol) and 10 and/or 13 (1 mmol) in acetic
acid (40 mL, 95%, v:v, 95 mL glacial acetic acid: 100 mL H2O) was
refluxed 12-18h. The reaction was followed by TLC analysis. The
solvent of the reaction mixture was removed under vacuum. The resi-
due was applied on plates chromayography (silica gel: toluene:
ethyl acetate: 10:1) in either purification of compound 11 and/or of
compound 14.
2-(2-Oxo-2-phenylethyl)-3-phenyl-1,2-dihydrobenzo[g]quinoxaline-
5,10-dione (11): Yield 365 mg (90%), brown powder (acetonitrile),
m.p. 290–292 °C. IR (KBr): ν = 3230 (NH), 3062–3010 (ArCH),

208 JOURNAL OF CHEMICAL RESEARCH 2011
2980–2860 (aliph-CH), 1708–1685 (CO), 1610 (C=N), 1592 (C=C).
1H NMR (400.134 MHz, CDCl3): δ = 9.80 (s, 1H, NH), 8.05–7.98 (m,
2H), 7.70–7.62 (m, 2H), 7.40–7.36 (m, 6H), 6.87–6.78 (m, 4H), 3.40
(dd, 1H, J = 15, 7.8 Hz), 2.70 (m, 1H, CH2), 2.54 (m, 1H, CH2) ppm.
13C NMR (100.6 MHz, CDCl3): see Fig. 1. MS (70 eV, EI), m/z (%):
406 [M+] (100), 302 (22), 288 (24), 212 (34), 186 (44), 172 (24), 134
(60), 104 (45), 76 (34). Anal. Calcd for C26H18N2O3 (406.43): C, 76.83;
H, 4.46; N, 6.89. Found: C, 76.74; H, 4.50; N, 6.76%.
(Z)-(2-Oxo-phenylethylidene)-3-phenyl-1,2-dihydrobenzo[g]quino-
xaline-5,10-dione (14):Yield 331 mg (82%), brown crystals (ethanol),
m.p. 300–302 °C. IR (KBr): ν = 3240 (NH), 3040–3000 (ArCH),
1705–1682 (CO), 1608 (C=N), 1592 (C=C). 1H NMR (400.134 MHz,
CDCl3): δ = 8.45–8.43 (dd, 1H, J = 7.8, 1.2 Hz), 8.40–8.37 (dd, 1H,
J = 7.8, 1.2 Hz), 6.92–7.80 (m, 6H), 7.60–7.54 (m, 3H), 7.49–7.38 (m,
4H), 6.65 (s, 1H, ethylenic-H) ppm. 13C NMR (100.6 MHz, CDCl3):
see Fig. 1. MS (70 eV, EI), m/z (%): 404 [M+] (100), 300 (24), 288
(24), 224 (20), 212 (30), 186 (36), 172 (26), 134 (56), 104 (40),
76 (42). Anal. Calcd for C26H16N2O3 (404.42): C, 77.22; H, 3.99;
N, 6.93. Found: C, 77.34; H, 3.92; N, 6.84%.
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The author thanks his student Mr Takek M. I. Badair for his
help.
Received 7 February 2011; accepted 1 March 2011
Paper 1100562 doi: 10.3184/174751911X13001124874111
Published online: 3 May 2011

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