Diammonium hydrogen phosphate as a neutral and efficient catalyst for synthesis of 1,8-dioxo-octahydroxanthene derivatives in aqueous media

Article abstract of DOI:10.1080/00397910701196520

A new and efficient method to synthesize a 3,3,6,6,9-aryl-1,8-dioxo- octahydroxanthene derivative using diammonium hydrogen phosphate as catalyst was performed in water at room temperature in a short periods. Copyright Taylor & Francis Group, LLC.

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Diammonium Hydrogen Phosphate as a
Neutral and Efficient Catalyst for Synthesis of
1,8‐Dioxo‐octahydroxanthene Derivatives in
Aqueous Media
Fatemeh Darviche a , Saeed Balalaie a , Fatemeh Chadegani a & Peyman
Salehi b
a Department of Chemistry, K. N. Toosi University of Technology, Tehran,
Iran
b Department of Phytochemistry, Medicinal Plants and Drugs Reasearch
Institute, Shahid Beheshti University, Evin, Tehran, Iran
Published online: 13 Oct 2010.
To cite this article: Fatemeh Darviche , Saeed Balalaie , Fatemeh Chadegani & Peyman Salehi
(2007): Diammonium Hydrogen Phosphate as a Neutral and Efficient Catalyst for Synthesis of
1,8‐Dioxo‐octahydroxanthene Derivatives in Aqueous Media, Synthetic Communications: An International
Journal for Rapid Communication of Synthetic Organic Chemistry, 37:7, 1059-1066
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Synthetic Communicationsw, 37: 1059–1066, 2007
Copyright # Taylor & Francis Group, LLC
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910701196520
Diammonium Hydrogen Phosphate as a
Neutral and Efficient Catalyst for Synthesis
of 1,8-Dioxo-octahydroxanthene Derivatives
in Aqueous Media
Fatemeh Darviche, Saeed Balalaie, and Fatemeh Chadegani
Department of Chemistry, K. N. Toosi University of Technology,
Tehran, Iran
Peyman Salehi
Department of Phytochemistry, Medicinal Plants and Drugs Reasearch
Institute, Shahid Beheshti University, Evin, Tehran, Iran
Abstract: A new and efficient method to synthesize a 3,3,6,6,9-aryl-1,8-dioxo-octa-
hydroxanthene derivative using diammonium hydrogen phosphate as catalyst was
performed in water at room temperature in a short periods.
Keywords: aqueous media, 3,3,6,6,9-aryl-1,8-dioxo-octahydroxanthene, diammonium
hydrogen phosphate
INTRODUCTION
In recent years, there has been an increased demand for “clean” and environ-
mentally friendly reactions in chemistry. In organic chemistry, synthesis is
mainly carried out in the solution phase, and organic solvents are usually the
first choice. These solvents are often problematic because of their toxicity,
flammability, or environmental hazards. The use of water as solvent has
been an active area of research in green chemistry.[1] In light of Breslow’s
Received in Poland July 13, 2006
Address correspondence to Saeed Balalaie, Department of Chemistry, K. N.
Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran. E-mail:
balalaie@kntu.ac.ir
1059

1060
F. Darviche et al.
1980 discovery of the enhancement of the rate of the Diels–Alder reaction in
water, organic chemists became interested in organic reactions in water.[2]
Soon it was discovered that many organic transformations can be performed
in water. Diammonium hydrogen phosphate is a water-soluble catalyst and
has been used in the synthesis of heterocyclic compounds[3] and alkenes.[4]
Xanthene derivatives occupy a prominent position in medicinal chemistry[5]
;
they have also been used as dyes,[6] pH-sensitive fluorescent materials,[7]
and laser technology.[8] Many procedures describe the synthesis of
xanthenes, including cyclodehydrations,[9] trapping of benzynes by
phenols,[10] cyclocondensation between 2-hydroxyaromatic aldehydes and
2-tetralone,[11] reaction of b-naphtol with aldehydes or acetals under acidic
conditions, and intramolecular phenyl carbonyl coupling reaction of benzal-
dehydes and acetophenones.[12] Dodecyl benzene sulfonic acid as phase-
transfer catalyst in aqueous media in reflux has been reported.[13] More
recently the grinding method has been used in the presence of a
superacid.[14] However, most of these reported procedures have disadvantages
including low yields, prolonged reaction times, use of an excess of reagents
and catalysts, and use of toxic organic solvents. These necessitate the develop-
ment of a new methodology for the synthesis of xanthene derivatives.
RESULTS AND DISCUSSION
Herein we report the condensation of aromatic aldehyde 1 with 5,5-dimethyl-
1,3-cyclohexanedione 2 in water in the presence of a catalytic amount of dia-
mmonium hydrogen phosphate (10% mol) at room temperature. After 1-2 h,
we obtain product 3 with good to excellent yield (Scheme 1). Product 4 can
be easily obtained in good yield by the addition of acid in reaction media
(Scheme 1).
Diammonium hydrogen phosphate, (NH4)2HPO4, is a very cheap,
nontoxic and water-soluble salt, and the pH of its aqueous solution (5 g/
100 ml) is in the range of 7.8–8.1. This reagent has been used in the manufac-
turing of many important materials, such as fire-proofing textiles, paper, wood,
and vegetable fibers.[15] It has also been used as a corrosion inhibitor and fer-
tilizer.[16] Diammonium hydrogen phosphate is a commercially available
compound that can be used in the laboratory without any special precaution.
Scheme 1.

Diammonium Hydrogen Phosphate
1061
To the best of our knowledge there are only two reports of the application of
diammonium hydrogen phosphate in organic synthetic methodology.[3,4]
To study the generality of this process, several examples illustrating this
method for the synthesis of products 3 and 4 were studied. The results are sum-
marized in Tables 1 and 2. The effect of substituents on the aromatic ring did
not show effects in terms of yields under these reaction conditions.
We can also obtained product 4 in one pot when we run the reaction in
MeOH at reflux condition in the presence of magnesium sulfate
(Scheme 1). The yields are shown in Table 2.
In conclusion, we have shown that diammonium hydrogen phosphate is a
mild catalyst in the synthesis of 3,3,6,6,9-aryl-1,8-dioxooctahydroxanthene.
Our procedure has significant advantages over the existing ones such as
general applicability, commercially available and safer reagents, and no
harmful organic solvent.
EXPERIMENTAL
Melting points were recorded on an Electrothermal 9100 melting-point
apparatus and BB FTLA-2000 spectrophotometer using KBr disks.1H NMR
spectra were recorded on Brucker DRX 300 (300 MHz) Avance spectrometer
in CDCl3 using TMS as the internal standard.
General Procedure for the Synthesis of 2,20-Arylmethylene Bis(3-
hydroxy-5,5-dimethyl-2-cyclohexene-1-one) Derivatives 3a–j
A mixture of aldehyde (1 mmol), dimedone (2.2 mmol, 308 mg), and diammo-
nium hydrogen phosphate (0.1 mmol, 13 mg) in 30 ml of water was stirred
Table 1. Synthesis of product 3a–j catalyzed by diammonium hydrogen phosphate in
water at 258C
Time
(min)
Yield
(%)
Mp (8C)
found
Mp (8C)
reported
Entry Product
Ar
1
2
3a
3b
3c
3d
3e
3f
4-Br- C6H4
4-Cl-C6H4
90
90
99
91
85
90
65
86
88
94
95
78
158–159
—
138–139 141–143[14]
3
4-CN-C6H4
2,4-Cl2-C6H3
4- OH-C6H4
4-OMe-C6H4
4-Me-C6H4
90
75
164–166
—
4
197–199 203–204[14]
188–190 188–190[14]
5
120
120
120
90
6
138
142–143[14]
7
3g
3h
3i
132–133 126–128[17]
151–152 161[18]
8
4-MeCONH-C6H4
4-NO2-C6H4
4-CF3-C6H4
9
10
90
75
192–194 188–190[14]
3j
130–132
—

1062
F. Darviche et al.
Table 2. Synthesis of product 4a–j catalyzed by acid in water at 258C
Yield
(%)
Mp (8C)
found
Mp (8C)
reported
Entry
Product
Ar
1
2
4a
4b
4c
4d
4e
4f
4-Br- C6H4
4-Cl-C6H4
72
70
78
70
65
80
75
71
66
72
255–256
232–233
215–217
248–250
247–249
245
—
230–231[14]
—
3
4-CN-C6H4
2,4-Cl2-C6H3
4-OH-C6H4
4-OMe-C6H4
4-Me-C6H4
4
250–252[14]
246–247[14]
241–243[14]
218–219[14]
—
5
6
7
4g
4h
4i
217–218
305–306
223–224
246–248
8
4-MeCONH-C6H4
4-NO2 -C6H4
4-CF3-C6H3
9
10
222[14]
4j
—
at room temperature for 1-2 h. The progress of the reaction was monitored by
thin-layer chromatography, TLC (eluent, petroleum ether–ethyl acetate 1:3).
After completion of the reaction, the product was filtered and washed with
water. Further purification was carried out by crystallization from EtOH.
General Procedure for the Synthesis of 1,8-
Dioxooctahydroxanthene Derivatives 4a–j
Method A
To a mixture of 1 mmol of 3a–j in 20 ml of MeOH, concentrated sulfuric acid
(0.1 ml) was added. The reactin mixture was stirred at room temperature for
15 min. The solid was filtered, and the remaining solution was neutralized
with NaOH 1 N solution. The solid products were collected.
Method B
A mixture of 1 mmol of 3a–j and magnesium sulphate in 30 ml of MeOH was
heated under reflux condition for 1-2 h. After completion of the reaction, the
organic solvent was evaporated, and the crude products were purified by crys-
tallization from EtOH.
Selected Data for Compounds 3a–j
1
3a: IR (KBr, cm21): nmax ¼ 3459, 2954, 2875, 1740, 1740, 1600. H NMR
(300 MHz, d, CDCl3): 1.13 (s, 6H, 2Me), 1.23 (s, 6H, 2Me), 2.18–2.40
(m, 8H, 4CH2), 5.47 (s, 1H, CH), 6.96 (d, 2H, J ¼ 6.6 Hz, H-Ar), 7.38
(d, 2H, J ¼ 6.6 Hz, H-Ar), 11.93 (brs, 1H, OH).

Diammonium Hydrogen Phosphate
1063
3b: IR (KBr, cm21): nmax ¼ 3455, 3016, 2970, 1736, 1589. 1H NMR
(300 MHz, d, CDCl3): 1.00 (s, 6H, 2Me), 1.23 (s, 6H, 2Me), 2.18–2.54
(m, 8H, 4CH2), 5.49 (s, 1H, CH), 7.02 (d, 2H, J ¼ 7.40 Hz, H-Ar), 7.22
(d, 2H, J ¼ 7.40 Hz, H-Ar), 11.88 (brs, 1H, OH).
1
3c: IR (KBr, cm21): nmax ¼ 3326, 2961, 2226, 1718, 1736, 1636, 1598. H
NMR (300 MHz, d, CDCl3): 1.12 (s, 6H, 2Me), 1.24 (s, 6H, 2Me), 2.30–
2.46 (m, 8H, 4CH2), 5.53 (s, 1H, CH), 7.20 (d, 2H, J ¼ 8.2 Hz, H-Ar), 7.57
(d, 2H, J ¼ 8.2 Hz, H-Ar), 11.81 (brs, 1H, OH).
3d: IR (KBr, cm21): nmax ¼ 3327, 2962, 1717, 1615. 1H NMR (300 MHz, d,
CDCl3): 1.08 (s, 6H, 2Me), 1.16 (s, 6H, 2Me), 2.16–2.51 (m, 8H, 4CH2), 5.66
(s, 1H, CH), 7.15 (d, 1H, J ¼ 8.20 Hz, H-Ar), 7.27 (brs, 1H, H-Ar), 7.38
(d, 1H, J ¼ 8.20 Hz, H-Ar), 11.84 (brs, 1H, OH).
3e: IR (KBr, cm21): nmax ¼ 3334, 2959, 2925, 1716, 1616. 1H NMR
(300 MHz, d, CDCl3): 1.14 (s, 6H, 2Me), 1.23 (s, 6H, 2Me), 2.19–2.50
(m, 8H, 4CH2), 5.49 (s, 1H, CH), 6.72 (d, 2H, J ¼ 8.4 Hz, H-Ar), 6.95
(d, 2H, J ¼ 8.4 Hz, H-Ar), 11.90 (brs, 1H, OH).
1
3f: IR (KBr, cm21): nmax ¼ 3450, 3013, 2957, 1586. H NMR (300 MHz, d,
CDCl3): 1.12 (s, 6H, 2Me), 1.25 (s, 6H, 2Me), 2.36–2.42 (m, 8H, 4CH2), 3.79
(s, 3H, OMe), 5.51 (s, 1H, CH), 6.62 (d, 2H, J ¼ 8.1 Hz, H-Ar), 6.82 (d, 2H,
J ¼ 8.1 Hz, H-Ar), 12.0 (brs, 1H, OH).
1
3g: IR (KBr, cm21): nmax ¼ 3460, 2961, 2928, 1735, 1736, 1596. H NMR
(300 MHz, d, CDCl3): 1.16 (s, 6H, 2Me), 1.25 (s, 6H, 2Me), 2.32–2.51
(m, 8H, 4CH2), 5.52 (s, 1H, CH), 6.99 (d, 2H, J ¼ 7.9 Hz, H-Ar), 7.13
(d, 2H, J ¼ 7.9 Hz, H-Ar), 11.88 (brs, 1H, OH).
1
3h: IR (KBr, cm21): nmax ¼ 3474, 3420, 3076, 1736, 1665, 1594. H NMR
(300 MHz, d, DMSO db):1.03 (s, 12H, 4Me), 2.01 (s, 3H, Me), 2.25–2.50
(m, 8H, 4CH2), 5.86 (s, 1H, CH), 6.85 (d, 2H, J ¼ 8.3 Hz, H-Ar), (7.28 (s,
1H, NH), 7.37 (d, 2H, J ¼ 8.3 Hz, H-Ar), 9.74 (S, 1H, OH), 9.80 (s, 1H, OH)).
1
3i: IR (KBr, cm21): nmax ¼ 3059, 2957, 1589, 1511, 1379, 1343. H NMR
(300 MHz, d, CDCl3): 1.13 (s, 6H, 2Me), 1.25 (s, 6H, 2Me), 2.31–2.54
(m, 8H, 4CH2), 5.56 (s, 1H, CH), 7.25 (d, 2H, J ¼ 7.40 Hz, H-Ar), 8.16
(d, 2H, J ¼ 7.40 Hz, H-Ar), 11.82 (brs, 1H, OH).
1
3j: IR (KBr, cm21): nmax ¼ 3068, 2958, 1709, 1593. H NMR (300 MHz, d,
CDCl3): 1.13 (s, 6H, 2Me), 1.25 (s, 6H, 2Me), 2.31–2.53 (m, 8H, 4CH2), 5.55
(s, 1H, CH), 7.22 (d, 2H, J ¼ 7.40 Hz, H-Ar), 7.54 (d, 2H, J ¼ 7.40 Hz,
H-Ar), 11.87 (brs, 1H, OH).

1064
F. Darviche et al.
4a: IR (KBr, cm21): nmax ¼ 3026, 2950, 1737, 1661. 1H NMR (300 MHz, d,
CDCl3): 1.00 (s, 6H, 2Me), 1.12 (s, 6H, 2Me), 2.20 (m, 4H, 2CH2), 2.48 (brs,
4H, 2CH2), 4.71 (s, 1H, H-9), 7.18 (d, 2H, J ¼ 7.8 Hz, H-Ar), 7.35 (d, 2H,
J ¼ 7.8 Hz, H-Ar).
4b: IR (KBr, cm21): nmax ¼ 2966, 2951, 1661. 1H NMR (300 MHz, d,
CDCl3): 1.00 (s, 6H, 2Me), 1.12 (s, 6H, 2Me), (2.15 (d, 2H, J ¼ 16 Hz,
CH2, H-2a, 7b), 2.25 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.48 (m, 4H,
2CH2, H-4,5)), 4.72 (s, 1H, H-9), 7.20 (d, 2H, J ¼ 8.6 Hz, H-Ar), 7.24
(d, 2H, J ¼ 8.6 Hz, H-Ar).
4c: IR (KBr, cm21): nmax ¼ 2957, 2934, 2225, 1662, 1619. 1H NMR
(300 MHz, d, CDCl3): 1.00 (s, 6H, 2Me), 1.13 (s, 6H, 2Me), (2.15 (d, 2H,
J ¼ 16 Hz, CH2, H-2a, 7b), 2.25 (d, 2H, J ¼ 16 Hz, CH2 H-2a0, 7b0), 2.50
(brs, 4H, 2CH2, H-4,5)), 4.78 (s, 1H, H-9), 7.43 (d, 2H, J ¼ 8.0 Hz, H-Ar),
7.53 (d, 2H, J ¼ 8.0 Hz, H-Ar).
1
4d: IR (KBr, cm21): nmax ¼ 2960, 2933, 1676, 1661. H NMR (300 MHz, d,
CDCl3): 1.03 (s, 6H, 2Me), 1.11 (s, 6H, 2Me), (2.16 (d, 2H, J ¼ 16 Hz, CH2,
H-2a, 7b), 2.24 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.46 (brs, 4H, 2CH2, H-
4,5)), 4.95 (s, 1H, H-9), 7.15 (d, 1H, J ¼ 8.2 Hz, H-Ar), 7.27 (brs, 1H, H-Ar),
7.38 (d, 1H, J ¼ 8.2 Hz, H-Ar).
4e: IR (KBr, cm21): nmax ¼ 3373, 2957, 1735, 1667, 1647. 1H NMR
(300 MHz, d, CDCl3): 1.02 (s, 6H, 2Me), 1.11 (s, 6H, 2Me), (2.16 (d, 2H,
J ¼ 16 Hz, CH2, H-2a, 7b), 2.23 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.47
(brs, 4H, 2CH2, H-4,5)), 3.15 (brs, 1H, OH), 4.68 (s, 1H, H-9), 6.61 (d, 2H,
J ¼ 8.5 Hz, H-Ar), 7.12 (d, 2H, J ¼ 8.5 Hz, H-Ar).
1
4f: IR (KBr, cm21): nmax ¼ 3002, 2955, 1739, 1668. H NMR (300 MHz, d,
CDCl3): 1.03 (s, 6H, 2Me), 1.12 (s, 6H, 2Me), (2.17 (d, 2H, J ¼ 16 Hz, CH2,
H-2a, 7b), 2.24 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.46 (brs, 4H, 2CH2, H-
4,5)), 3.75 (s, 3H, OMe), 4.70 (s, 1H, H-9), 6.77 (d, 2H, J ¼ 8.5 Hz, H-Ar),
7.22 (d, 2H, J ¼ 8.5 Hz, H-Ar).
4g: IR (KBr, cm21): nmax ¼ 3038, 2958, 1690, 1661, 1626. 1H NMR
(300 MHz, d, CDCl3): 1.00 (s, 6H, 2Me), 1.10 (s, 6H, 2Me), (2.17 (d, 2H,
J ¼ 16 Hz, CH2, H-2a, 7b), 2.23 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.25
(s, 3H, Me), 2.46 (brs, 4H, 2CH2, H-4,5)), 4.72 (s, 1H, H-9), 7.02 (d, 2H,
J ¼ 7.5 Hz, H-Ar), 7.18 (d, 2H, J ¼ 7.5 Hz, H-Ar).
1
4h: IR (KBr, cm21): nmax ¼ 3373, 3124, 2956, 1692, 1653, 1622, 1599. H
NMR (300 MHz, d, CDCl3) d: 1.00 (s, 6H, 2Me), 1.11 (s, 6H, 2Me), 2.14
(s, 3H, Me), (2.18 (d, 2H, J ¼ 16 Hz, CH2, H-2a, 7b), 2.25 (d, 2H,
J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.47 (brs, 4H, 2CH2, H-4,5)), 4.70 (s, 1H,

Diammonium Hydrogen Phosphate
1065
H-9), 7.23 (d, 2H, J ¼ 8.3 Hz, H-Ar), 7.34 (d, 2H, J ¼ 8.3 Hz, H-Ar), 7.45
(brs, 1H, NH).
1
4i: IR (KBr, Cm21): nmax ¼ 2957, 2868, 1660, 1614, 1513, 1361. H NMR
(300 MHz, d, CDCl3): 1.00 (s, 6H, 2Me), 1.13 (s, 6H, 2Me), (2.17 (d, 2H,
J ¼ 16 Hz, CH2, H-2a, 7b), 2.27 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.50
(brs, 4H, 2CH2, H-4,5)), 4.84 (s, 1H, H-9), 7.48 (d, 2H, J ¼ 8.6 Hz, H-Ar),
8.11 (d, 2H, J ¼ 8.6 Hz, H-Ar).
1
4j: IR (KBr, cm21): nmax ¼ 2961, 2869, 1664, 1621. H NMR (300 MHz, d,
CDCl3): 1.00 (s, 6H, 2Me), 1.13 (s, 6H, 2Me), (2.18 (d, 2H, J ¼ 16 Hz, CH2,
H-2a, 7b), 2.27 (d, 2H, J ¼ 16 Hz, CH2, H-2a0, 7b0), 2.50 (brs, 4H, 2CH2, H-
4,5)), 4.81 (s, 1H, H-9), 7.43 (d, 2H, J ¼ 8.2 Hz, H-Ar), 7.49 (d, 2H,
J ¼ 8.2 Hz, H-Ar).
ACKNOWLEDGMENTS
Saeed Balalaie is grateful to the Alexander von Humboldt foundation for a
research fellowship and equipment donation. Partial support of this work by
the K. N. Toosi University of Technology Research Council is gratefully
acknowledged.
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