Synthesis of new naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione and Anthra-9,10-quinone Dyes from Furan-2,3-diones

Article abstract of DOI:10.3390/molecules14041429

Novel naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione and anthra-9,10-quinone dyes were synthesized in good yield from furan-2,3-diones using 1,2-diaminoanthra-9,10-quinone and 1,4-diaminoanthra-9,10-quinone. The chromophores were characterized by molecular s

Full text of DOI:10.3390/molecules14041429

Molecules 2009, 14, 1429-1437; doi:10.3390/molecules14041429
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molecules
ISSN 1420-3049
www.mdpi.com/journal/molecules
Article
Synthesis of New Naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione
and Anthra-9,10-quinone Dyes from Furan-2,3-diones
Şevket Hakan Üngören
Department of Chemistry, Faculty of Arts and Sciences, Bozok University, Yozgat, Turkey. Tel.: +90
354 2421022; fax: +90 354 2421022; E-mails: hungoren@erciyes.edu.tr;
shakan.ungoren@bozok.edu.tr
Received: 11 March 2009; in revised form: 26 March 2009 / Accepted: 30 March 2009 /
Published: 2 April 2009
Abstract: Novel naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione and anthra-9,10-quinone
dyes were synthesized in good yield from furan-2,3-diones using 1,2-diaminoanthra-9,10-
quinone and 1,4-diaminoanthra-9,10-quinone. The chromophores were characterized by
molecular spectroscopy methods.
Keywords: Naphtho[2,3-f]quinoxaline-2,7,12(1H)-triones; Anthra-9,10-quinones; Furan-
2,3-diones; Diaminoanthra-9,10-quinone; Dye modification; Vat dyes.
1. Introduction
Anthra-9,10-quinones and their condensed derivatives with heterocycles such as indanthrone
(Pigment Blue 60, I), anthrapyrimidine (Pigment Yellow 108, II) and Vat Yellow 3 (III) (Figure 1)
possess brilliant hues and very good fastness and represent an important group of vat dyes for the
textile industry [1,2]. In addition to these properties, some anthra-9,10-quinone dyes are widely used in
other fields, such as in medicine and food chemistry [3] and high-technology systems [4].
Consequently, anthra-9,10-quinones are interesting compounds from the viewpoint of both their
reactions and applications.
Furan-2,3-diones (1) have been shown to be very useful synthons for the preparation of various
heterocycles. These compounds show typical carbonyl and lactone reactions, depending on the
structures of the nucleophiles involved [5-8]. For example, furan-2,3-diones undergo
cyclocondensations with 1,2-diamines to provide the corresponding quinoxalines and aromatic amines

Molecules 2009, 14
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react with furan-2,3-diones to give the corresponding Schiff bases and pyrrole-2,3-dione derivatives,
depending on the reaction times and temperature [5,9].
Figure 1. Some commercial vat dyes.
O
O
O
N
O
N
O
Ph
HN
NH
Ph
O
O
HN
NH
O
O
NH
O
O
O
III
II
I
Furan-2,3-diones (1) can offer many possibilities for the construction of various heterocyclic dyes
including the new naphtho[2,3-f]quinoxaline and anthra-9,10-quinone derivatives reported herein. In
this work we present new anthra-9,10-quinone (2) and naphtho[2,3-f]quinoxaline (3) dyes derived
from the reactions of some furan-2,3-diones with 1,2-diaminoanthra-9,10-quinone (1,2-DAAQ) and
1,4-diaminoanthra-9,10-quinone (1,4-DAAQ), acting as bifunctional nucleophiles.
2. Results and Discussion
Furan-2,3-dione starting materials 1a-f were prepared according to the literature [10-13]. The C5
atom of compounds 1a-d smoothly reacted with the amino group of 1,2-DAAQ and 1,4-DAAQ to give
compoubds 2 under mild conditions and in high yields (75-90%, Scheme 1).
Scheme 1. Synthesis of compounds 2.
O
O
O
NH2
O
R1
O
COOH
O
R1
R2
(i)
R2
NH
+
O
O
NH2
O
NH2
O
1a-d
1,4-DAAQ
2a-d
O
O
O
O
O
COOH
NH2
Ph
Ph
(i)
O
O
NH
O
H2N
O
NH2
O
1,2-DAAQ
2e
1a
1
2
1
2
1
2
1
2
1, 2: a R , R = Ph; b R , R = 4-MeOPh; c R , R = 4-MePh; d R = Me, R = 4-MePh
Reaction conditions: (i) Benzene, RT, 48 h.

Molecules 2009, 14
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Due to the greater reactivity of the amino group attached to the C2 atom of 1,2-DAAQ, compared
with the amino group attached to the C1 atom of 1,2-DAAQ, 1,2-DAAQ was modified from the amino
group attached to C2-position of 1,2-DAAQ to give 2e. On the other hand, the amino group attached to
the C2 atom of 1,2-DAAQ did not react with the C5 atom of 1a at higher temperature, but reacted with
the C3 atom of 1a by forming a Schiff base, which was not isolated (as outlined in Scheme 2). Through
attack of the second amino group on the lactone carbonyl group, ring opening occurs. The reactions of
1,2-DAAQ with 1b,c,e,f run via the same reaction pathways to give 3 in nearly quantitative yields of
90-96% in boiling benzene. This proposed mechanism is similar to that reported in the literature for
the reaction pathways of furan-2,3-diones with 1,2-diamino nucleophiles [9,14].
Scheme 2. Synthesis of compounds 3.
R2
O
R1
O
O
NH2
O
O
R1
R2
H2N
O
NH2
(ii)
O
O
+
N
O
O
O
1
1,2-DAAQ
R1
O
O
R2
NH
O
N
OH
1d
3d
O
3
1, 3: a R1, R2 = Ph; b R1, R2 = 4-MeOPh; c R1, R2 = 4-MePh;
d R1= Me, R2 = 4-MePh e R1, R2 = 3,4-(MeO)2Ph; f R1 = Ph, R2 = Ph-CH=CH-
Reaction conditions: (ii) Benzene, reflux, 2 h.
The structures of 2 and 3 were confirmed by spectroscopic data and agree with those found for
similar compounds [4,9,14,15]. In the NMR spectra, the methine proton signal (low intensity) also
revealed that compound 2 occurs as tautomers (2A and 2B), with tautomer 2B as a minor contributor
in DMSO-d6 solutions (Scheme 3). The 13C-NMR spectroscopic data of 2 also agree with the proposed
tautomeric structures.
Scheme 3. Tautomeric forms (2A and 2B) of 2a-e in DMSO-d6.
COOH
COOH
O
O
R1
R1
O
O
N
H
N
R2
R2
AQ
AQ
2B
2A

Molecules 2009, 14
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There was indication of tautomeric forms 3A (and 3B as a minor contributor) in 3a,f (but not
1
3b,c,e) in their H-NMR spectra in DMSO-d6 solution (Scheme 4). However, there was no signal for
13
the methine proton belonging to the tautomer 3C in DMSO-d6 solution. The C-NMR spectra of 3
could not be recorded due to its very low solubility in organic solvents, but the condensation was
verified by the detection of the [MH+] and [MH+-H2O] signals.
Scheme 4. Tautomeric forms (3A-C) of 3a,f in DMSO-d6.
R1
H
R1
O
R1
N
O
O
O
H
O
O
O
R2
R2
NH
NH
NH
O
O
O
O
O
N
O
R2
N
O
H
O 3B
3C
3A
The UV-vis absorption spectra of 3a-c,e in DMF at a concentration of 3.333 x 10-5 mol/L are shown
in Figure 2. The results are also listed in Table 1. In the visible region, the molar absorption
coefficients and the absorption maxima of compounds 3 were observed in the range 1.119x104 to
1.545x104 dm3 mol-1 cm-1 (380-394 nm), 1.161x104 to 1.557x104 (397-412 nm), 1.467x104 to 1.842x104
(498-515 nm), there being no significant difference between them. The visible absorption spectrum is
dominated by the characteristic anthraquinone bands in the region 380-400 nm [15].
Figure 2. UV-Vis spectra of compound 3 in DMF.
1
3a
3b
3c
3e
0
250
300
350
400
450
500
550
600
650
700
750
Wavelength / nm (Optical path: 10 mm)

Molecules 2009, 14
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Table 1: UV-Vis spectral data of 3.
UV-Vis
Compounds
λ1-4max (nm),

(liter mol-1 cm-1)
380, 397,
2.592x104 1.398x104 1.416x104
293, 394, 412,
3.066x104 1.545x104 1.557x104
275, 382, 400,
2.652x104 1.119x104 1.161x104
278, 386, 402,
2.865x104 1.434x104 1.518x104
3a
3b
3c
3e
274,
498,
1.716x104
515,
1.842x104
501,
1.467x104
507,
1.677x104
3. Experimental Section
3.1. General
Solvents were purchased from Merck and Carlo Erba. Diaminoanthra-9,10-quinones were
purchased from Aldrich and used without further purification. 1H- and 13C-NMR spectra were recorded
using a Bruker Ultrashield spectrometer operating at 300.13 MHz (1H) and 75.47 MHz (13C). UV-vis
spectra: Shimadzu UV-1280 spectrophotometer. IR Spectra: Jasco Plus Model 460 FTIR spectrometer;
in cm-1. Elemental analyses (C, H, N) were performed using a Leco CHNS-O 932. Melting points were
measured with an Electrothermal 9200 apparatus. GC/MS measurements were performed using a gas
chromatograph (Model 6890 Series)-mass selective detector (Model 5973N) system (Agilent
Technologies).
3.2. General Procedure for the Preparation of Compounds 2a-e
Compound 1 (1 mmol) and 1,2-/1,4-DAAQ (1 mmol) in benzene (60 mL) was stirred for 48 h. The
precipitate 2 was filtered off and recrystallized from DMF.
4-[(4-Amino-9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-3-benzoyl-2-oxo-4-phenylbut-3-enoic
acid (2a): Obtained from 1a (0.278 g, 1 mmol) and 1,4-DAAQ (0.238 g, 1 mmol). Mp. 195-196 C as
1
dark-blue crystals (0.415 g, 80%); H-NMR (DMSO-d6):  = 13.50 (1H, s, NH), 8.77-6.35 (16H, m,
13
aromatic), 7.16 (2H, s, NH2, br), 4.89 (Ar-CO-CH-CO, tautomer B), COOH not observed; C-NMR
(DMSO-d6):  = 193.29, 192.53, 188.81, 184.79, 183.47, 181.49 (C=O), 157.60, 152.96, 150.81,
147.19, 139.82, 137.98, 135.72, 135.04, 134.82, 134.55, 134.12, 134.05, 133.95, 133.84, 133.71,
133.47, 133.08, 132.68, 132.20, 132.07, 130.92, 130.47, 129.98, 129.70, 129.57, 129.40, 129.29,
129.12, 129.04, 128.86, 128.69, 128.15, 128.00, 127.87, 127.06, 126.46, 126.20, 124.43, 120.96,
118.32, 113.17, 111.94, 110.63, 110.20, 107.97, 93.69 (C=C, arom., aliph.), 64.05 (-CH-); IR (KBr) 

Molecules 2009, 14
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3450 (OH, br); 3445, 3427 (NH2); 3302 (NH); 1724, 1690, 1670, 1636 cm-1 (C=O); Anal. Calcd for
C31H20N2O6 (516.5): C, 72.09; H, 3.90; N, 5.42. Found: C, 72.26; H, 3.88; N, 5.28.
4-[(4-Amino-9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-3-(4-methoxybenzoyl)-4-(4-methoxy-
phenyl)-2-oxobut-3-enoic acid (2b): Obtained from 1b (0.338 g, 1 mmol) and 1,4-DAAQ (0.238 g, 1
mmol). Mp 215-216 C as black crystals (0.503 g, 87%); 1H-NMR (DMSO-d6):  = 13.55, 13.48 (1H,
d, NH), 8.97-6.70 (14H, m, aromatic), 7.07 (2H, s, NH2, br), 4.72 (Ar-CO-CH-CO, tautomer B), 3.86,
3.79 (6H, s, OCH3), COOH not observed; 13C-NMR (DMSO-d6):  = 192.73, 191.76, 191.50, 184.62,
183.51, 181.49 (C=O, C=N), 164.44, 163.45, 162.77, 161.41 (C=C-OCH3, tautomer A and B ), 157.78,
147.20, 135.07, 134.56, 134.12, 133.98, 133.08, 132.70, 131.79, 131.72, 131.36, 131.04, 129.91,
129.29, 128.72, 127.59, 127.08, 126.47, 126.21, 114.77, 114.56, 113.54, 107.97, 91.94 (C=C, arom.,
aliph.), 65.24 (-CH-) 36.24, 34.64, 31.23 (OCH3); IR (KBr)  3455 (OH, br); 3425 (NH2); 3300 (NH);
1726, 1686, 1664, 1638 cm-1 (C=O); Anal. Calcd for C33H24N2O8 (576.6): C, 68.75; H, 4.20; N, 4.86.
Found: C, 68.84; H, 4.40; N, 4.81.
4-[(4-Amino-9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-3-(4-methylbenzoyl)-4-(4-methylphenyl)-
2-oxobut-3-enoic acid (2c): Obtained from 1c (0.306 g, 1 mmol) and 1,4-DAAQ (0.238 g, 1 mmol).
1
Mp 220-221C as navy-blue crystals (0.493 g, 90%); H-NMR (DMSO-d6):  = 13.54, 13.49 (1H, d,
NH), 8.77-6.62 (14H, m, aromatic), 7.58 (2H, s, NH2, br), 4.79 (Ar-CO-CH-CO, tautomer B), 3.45
13
(1H, s, COOH, br), 2.41, 2.31 (14H, s, CH3); C-NMR (DMSO-d6):  = 192.95, 192.69, 192.61,
187.08, 183.55, 181.49 (C=O, C=N), 157.69, 150.24, 147.21, 145.48, 135.11, 134.56, 134.00, 133.90,
133.33, 133.15, 132.70, 130.99, 130.09, 129.87, 129.79, 129.46, 129.38, 129.30, 128.80, 128.17,
127.88, 127.18, 127.11, 126.49, 126.21, 118.36, 110.22, 107.95 (C=C, arom., alph.), 63.83 (-CH-),
21.71, 21.55 (CH3); IR (KBr)  3480 (OH, br); 3442 (NH2); 3308 (NH); 1725, 1689, 1671, 1663, 1638
cm-1 (C=O); Anal. Calcd for C33H24N2O6 (544.6): C, 72.78; H, 4.44; N, 5.14. Found: C, 72.92; H, 4.35;
N, 4.96.
3-Acetyl-4-[(4-amino-9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-4-(4-methylphenyl)-2-oxobut-3-
enoic acid (2d): Obtained from 1d (0.230 g, 1 mmol) and 1,4-DAAQ (0.238 g, 1 mmol). Mp 174-175
1
C as brown crystals (0.419 g, 90%); H-NMR (DMSO-d6):  = 13.54, 13.44 (1H, d, NH), 8.92-6.86
(10H, m, aromatic), 7.58 (2H, s, NH2, br), 4.64 (Ar-CO-CH-CO, tautomer B), 3.51 (1H, s, COOH, br),
13
2.39 (3H, s, COCH3), 2.22 (3H, s, C=C-CH3); C-NMR (DMSO-d6):  = 200.05, 192.45, 186.70,
183.39, 181.47 (C=O, C=N), 152.97, 150.05, 147.19, 146.02, 136.21, 135.72, 134.92, 134.54, 133.92,
133.76, 133.09, 132.69, 131.21, 130.20, 130.04, 129.88, 129.70, 129.37, 129.27, 128.07, 127.00,
126.41, 126.20, 117.89, 116.76, 109.96, 107.95, 105.96 (C=C, arom., alph.), 36.25 (COCH3), 21.59
(CH3); IR (KBr)  3475 (OH, br); 3432 (NH2); 3300 (NH); 1734, 1685, 1666, 1637, 1638 cm-1 (C=O);
Anal. Calcd for C27H20N2O6 (468.4): C, 69.22; H, 4.30; N, 5.98. Found: C, 69.16; H, 4.15; N, 5.75.
4-[(1-Amino-9,10-dioxo-9,10-dihydroanthracen-2-yl)amino]-3-benzoyl-2-oxo-4-phenylbut-3-enoic
acid (2e): Obtained from 1a (0.278 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol). Mp 255-256 C as
1
brown crystals (0.386 g, 75%); H-NMR (DMSO-d6):  = 15.23 (1H, s, NH), 8.31-6.94 (16H, m,
13
aromatic), 7.16 (2H, s, NH2, br), 3.38 (1H, s, br, COOH); C-NMR (DMSO-d6):  = 194.27, 191.87,

Molecules 2009, 14
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188.77, 186.80, 185.32, 181.44 (C=O, C=N), 144.54, 142.51, 142.14, 134,56, 134.29, 133.54, 131,07,
129.63, 129.15, 128.43, 128.10, 127.86, 127.66, 127.51, 127.02, 126.60, 126.41, 125.63, 124.56,
124.18, 116.88, 109.01 (C=C, arom., alph.); IR (KBr)  3435 (OH, br, NH2); 3211 (NH); 1717, 1658,
1649, 1639 cm-1 (C=O); Anal. Calcd. for C31H20N2O6 (516.5): C, 72.09; H, 3.90; N, 5.42%. Found: C,
72.39; H, 3.72; N, 5.61.
3.3. General Procedure for the Preparation of Compounds 3a-c,e,f
Compound 1 (1 mmol) and 1,2-DAAQ (1 mmol) in benzene (40 ml) was refluxed for 2 h. The red-
coloured precipitate (3) was filtered off and recrystallized from DMSO. 
3-(1-Benzoyl-2-oxo-2-phenylethyl)naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione (3a): Obtained from

1
1a (0.278 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol). Mp 341-343 C; 0.517 g, 94%; H-NMR
(DMSO-d6):  = 15.70, 15.07 (1H, s, OH, br), 13.25, 12.27 (1H, s, NH-C=O, br), 8.33-6.79 (16H, m,
Ar-H); IR (KBr)  3435 (OH), 3210 (NH), 3072, 2925 (C-H), 1694, 1661, 1651, 1621 cm-1 (C=O); MS
(ESI)+: m/z 498 (1%) [M+H]+; Anal. Calcd for C31H18N2O5 (498.5): C, 74.69; H, 3.64; N, 5.62. Found:
C, 74.78; H, 3.68; N, 5.60.
3-[1-(4-Methoxybenzoyl)-2-(4-methoxyphenyl)-2-oxoethyl]naphtho[2,3-f]quinoxaline-2,7,12(1H)-
trione (3b): Obtained from 1b (0.338 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol); Mp 347-349 C;
1
0.517 g, 92%; H-NMR (DMSO-d6):  = 15.45 (1H, s, OH, br), 12.45 (1H, s, NHCO, br), 8.48-6.70
(14H, m, Ar-H), 3.80, 3.74 (6H, s, OCH3); IR (KBr)  3437 (OH), 3214 (NH), 3069, 2926 (C-H),
1695, 1664, 1654, 1638 cm-1 (C=O); MS (ESI)+: m/z 559 (5%) [M+H]+, m/z 541 (6%) [MH-H2O]+;
Anal. Calcd for C33H22N2O7 (558.5): C, 70.96; H, 3.97; N, 5.02. Found: C, 70.79; H, 3.93; N, 5.17.
3-[1-(4-Methylbenzoyl)-2-(4-methylphenyl)-2-oxoethyl]naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione
(3c): Obtained from 1c (0.306 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol); Mp 315-317 C; 0.473 g,
90%; 1H-NMR (DMSO-d6):  = 15.50 (1H, s, OH, br), 12.43 (1H, s, NHCO), 8.29-7.06 (14H, m, Ar-
H), 2.34, 2.26 (6H, s, CH3); IR (KBr) v 3432 (OH), 3200 (NH), 3071, 2914 (C-H), 1693, 1663, 1656,
1638 cm-1 (C=O); MS (ESI)+: m/z 526 (13%) [M+H]+, m/z 525 (25%) [M]+; Anal. Calcd for
C33H22N2O5 (526.5): C, 75.28; H, 4.21; N, 5.32. Found: C, 75.04; H, 4.29; N, 5.49.
3-[1-(3,4-Dimethoxybenzoyl)-2-(3,4-dimethoxyphenyl)-2-oxoethyl]naphtho[2,3-f]quinoxaline-
2,7,12(1H)-trione (3e): Obtained from 1e (0.398 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol); Mp

1
309-311 C; 0.587 g, 95%; H-NMR (DMSO-d6):  = 15.44 (1H, s, OH, br), 12.35 (1H, s, NHCO),
8.33-6.88 (12H, m, Ar-H), 3.81, 3.79, 3.75, 3.48 (12H, s, OCH3); IR (KBr) v 3436 (OH), 3253 (NH),
3075, 2932 (C-H), 1698, 1660, 1654, 1640 cm-1 (C=O); MS (ESI)+: m/z 619 (6%) [M+H]+, m/z 601
(2%) [MH-H2O]+; Anal. Calcd for C35H26N2O9 (618.6): C, 67.96; H, 4.24; N, 4.53. Found C, 68.17; H,
4.24; N, 4.60.
3-[(3E)-1-Benzoyl-2-oxo-4-phenylbut-3-en-1-yl]naphtho[2,3-f]quinoxaline-2,7,12(1H)-trione
(3f):
Obtained from 1f (0.304 g, 1 mmol) and 1,2-DAAQ (0.238 g, 1 mmol); Mp 307-308 C; 0.472 g, 90%;

Molecules 2009, 14
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1H-NMR (DMSO-d6):  = 15.64, 14.55 (1H, s, OH, br), 12.35, 12.11 (1H, s, NH), 8.28-6.82 (16H, m,
Ar-H), 7.74 (1H, d, J = 15.4 Hz, CH=), 6.64 (1H, d, J = 15.3 Hz, CH=); IR (KBr) v 3435 (OH), 3213
(NH), 3062, 2853 (C-H), 1696, 1664, 1657, 1638 cm-1 (C=O); MS (ESI)+: m/z 525 (6%) [M+H]+, m/z
508 (3%) [MH-H2O]+; Anal. Calcd for C33H20N2O5 (524.5): C, 75.56; H, 3.84; N, 5.34. Found: C,
75.53; H, 3.80; N, 5.41.
4. Conclusions
We have designed and easily synthesized novel naphtho[2,3-f]quinoxaline-2,7,12(1H)-triones and
anthra-9,10-quinones in good to excellent yields as potential vat dyes from furan-2,3-diones. Their
spectroscopic properties in solution and in the solid state are reported. For commercial dye production,
reactions with high yields and relatively straightforward chemistry are preferred. It was seen that
furan-2,3-diones have good reactivity to meet these expectations. We believe that preparation of
various heterocyclic dyes based on furan-2,3-dione chemistry might make a contribution to the
development of high performance pigments. Performances of new dyes will be tested in future studies.
Acknowledgements
The author is very grateful to Dr. İrfan Koca and Ress. Assist. Bilal Nişancı for technical assistance.
References and Notes
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3. Orban, N.; Boldizsar, I.; Szucs, Z.; Danos, B. Influence of different elicitors on the synthesis of
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77, 249-257, and references therein.
4. Matsui, M.; Taniguchi, S.; Suzuki, M.; Wang, M.; Funabiki, K.; Shiozaki, H. Dyes produced by
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Sample Availability: Samples of the compounds 2a-e and 3a,b,c,e,f are available from the authors.
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