Synthesis of 5,5'-(arylmethylene)bis(pyrimidinone) derivatives in aqueous media

Article abstract of DOI:10.3184/030823408X390190

The condensation and addition reactions of aromatic aldehydes and 4,6-dihydroxypyrimidine or 2,4-dihydroxy-6-aminopyrimidine in water in the presence of triethylbenzylammonium chloride (TEBAC) afford a one-pot synthesis of 5,5'-(arylmethylene)bis[6-hydroxypyrimidine-4(3H)-one]s and 5,5'-(arylmethylene)bis[6-aminopyrimidine-2,4 (1H,3H)-dione]s. These compounds were characterised by elemental analysis and IR and ¹H NMR spectra and further confirmed by a single crystal X-ray diffraction analysis.

Full text of DOI:10.3184/030823408X390190

JOURNAL OF CHEMICAL RESEARCH 2008
DECEMBER, 719-721
RESEARCH PAPER 719
Synthesis of 5,5
1
-(arylmethylene)bis(pyrimidinone)
derivatives in
aqueous media
Da-Oing Shia,b*, Li-Hui Niub and Oi-Va Zhuangb
aCollege of Chemistry and Chemical Engineering, Key Laboratory of Organic Synthesis of Jiangsu Province, Suzhou University,
Suzhou 215123, P.R. China
bCollege of Chemistry and Chemical Engineering, Xuzhou Normal University, Xuzhou 221116, P.R. China
The condensation and addition reactions of aromatic aldehydes and 4,6-dihydroxypyrimidine
or 2,4-dihydroxy-6-
aminopyrimidine
in water in the presence of triethylbenzylammonium
chloride (TEBAC) afford a one-pot synthesis
of 5,5' -(a ryl methylene )bis[ 6-hyd roxypyri m id ine-4(3H )-one]s
and 5,5' -(a ryl methylene )bis[ 6-am inopyrim id ine-2,4
(1H,3H)-dione]s. These compounds were characterised by elemental analysis and IR and 1H NMR spectra and further
confirmed by a single crystal X-ray diffraction analysis.
Keywords: 5,5'-(arylmethylene)bis(pyrimidinone),
pyrimidine, aqueous media
aromatic aldehyde, 4,6-dihydroxypyrimidine, 2,4-dihydroxy-6-amino-
The importance of uracil and its annelated derivatives is well
recognised by syntheticl -4 as well as biologica15-10chemists.
With the development of clinically useful anticancer and
antiviral drugs,11-14 there has recently been remarkable
interest in the synthetic manipulations of uracils.15-17Jiang
and Roberts 18reported the synthesis of 5,5'- {(perfluorophenyl)
methylene }bis(6-amino-l ,3-dimethylpyrimidine-2,4-dione)
in glacial acetic acid under nitrogen. But the yield was only
44%. Azizian et a[.l9 reported the synthesis of bis(6-amino-
pyrimidonyl)methanes using thermal (in ethanol at 80°C) or
microwave-assisted solvent-free methods. Moskvin et al.2o
reported the synthesis of 5,5'-methylenebis(4,6-dihydroxy-2-
methylthiopyrimidines) by condensation of 4,6-dihydroxy-
2-methylthiopyrimidine with formaldehyde and aromatic or
heterocyclic aldehydes in ethanol. However, they were reacted
in organic solvents or had low yields.18
The need to reduce the amount of toxic waste and byproducts
arising from chemical processes requires increasing emphasis
on the use of less toxic and environmentally compatible
materials in the design of new synthetic methods.21-23 In
one of the most promising approaches, water is used as the
reaction medium.24-26 Breslow and Rideout,27,28 showed
that hydrophobic effects could strongly enhance the rate of
several organic reactions and rediscovered the use of water
as a solvent in organic chemistry in the 1980s. In recent
years, there has been increasing recognition that water is
an attractive medium for many organic reactions.29-34The
aqueous medium is less expensive, less dangerous and more
environment-friendly than an organic solvent. Generally, the
low solubility35 of most reagents in water is not an obstacle
to reactivity, which on the contrary, is reduced with the use of
cosolvents. Based on our previous studies on the use of water
as the solvent for carrying out carbon-carbon bond-forming
reactions under heterogeneous catalysis,36-39we report here
a novel synthesis of 5,5'-(arylmethylene)bis(pyrimidinone)
derivatives using water as the reaction medium.
o
Ar
0
o
HN~
TEBAC, H20,
HN~NH
ArCHO
+
~ Jl
90°C
~~IJ\ )lNJ
N
OH
N
OH HO
N
2
3
Scheme
1
Table
Entry
1
The syntheses of 3 in aqueous media
Ar
Isolated yield/%
t/h
3-N02C6H4
4-BrC6H4
2-N02C6H4
4-HOC6H4
3.4-CI2C6H3
4-N02C6H4
10
9
12
12
14
8
79
62
73
86
75
84
3a
3b
3c
3d
3e
3f
o
TEBAC, H20.
ArCHO
+
oA
N
HN~ JlNH2
900C
H
4
5
Scheme
2
Table
Entry
2
The syntheses of 5 in aqueous media
Ar
Isolated yield/%
t/h
3-N02C6H4
4-N02C6H4
2-CIC6H4
4-CIC6H4
3-CIC6H4
8
96
94
81
86
91
5a
5b
5c
5d
5e
6
12
10
8
When aromatic aldehydes 1 and 4,6-dihydroxypyrimidine
2 were stirred at 90°C for 8-14 h in water in the presence of
triethylbenzylannnonium chloride (TEBAC), the desired
products 5,5'-(arylmethylene )bis[6-hydroxypyrimidine-4(3H)-
one]s 3 were obtained in moderate to good yields (Scheme 1).
The results are summarised in Table 1.
The structures of the compounds 3 and 5 were established on
the basis of spectroscopic data, particularly I H NMR analysis.
The structure of3c was further confirmed by X-ray diffraction
analysis. Crystallographic data are presented in Table 3.
An ORTEP plot and the atom numbering are given in Fig.
1. The structure exhibits intermolecular hydrogen bonds:
N2-H. .. 02 (-x + 2, -y, -z), N3-H ... Nl (x - 1/2, -y + 1/2,
z - 1/2) and 0l-H. .. 03 (x + 1/2, -y + 1/2, z + 1/2) and an
intramolecular hydrogen bond: 04-H ... Ol, which helps in
stabilising the crystal structure.
Similarly, the reaction of aromatic aldehyde
2,4-dihydroxy-6-aminopyrimidine under the same
reaction conditions afforded 5,5'-(arylmethylene)bis[6-
1 and
4
aminopyrimidine-2,4(lH,3H)-dione]s
results are summarised in Table 2.
5 (Scheme 2) and the
* Correspondent. Email: dqshi@263.net

720 JOURNAL OF CHEMICAL RESEARCH 2008
Table 3 Crystal data and structure refinement of compound 3c
Empirical formula
Formula weight
Temperature
C39H43N130'5
933.86
298(2) K
N7
C.9
Wavelength
Crystal system
Space group
Unit cell dimensions
0.71073 A
Monoclinic
P2,/n
a = 11.6719(15) A a = 90°
b = 15.0583(18) A ~ =
93.631(2)°
c = 12.644?(16) Ay = 90°
2217.9(5) A3
05
fiC20A
C20
Volume
Z
Density (calculated)
Absorption coefficient
F(OOO)
2
C5
1.398 mg/m3
0.110 mm-'
976
N3
07
Crystal size
Theta range for data collection
0.31 x 0.25 x 0.13 mm
2.45 to 25.03°
N4
Index ranges
-13:'0 h:'O 13, -17:'0 k:'O 17,
-8:'0/:'015
Fig. 1 The X-ray crystal structure of compound 3c.
Reflections collected
Independent reflections
Absorption correction
11498
3912 [R(int) = 0.0343]
Semi-empirical from
equ ivalents
Full-matrix least-squares on F2
3912/0/344
General procedure for the synthesis of 5,5'-(arylmethylene)bis
(pyrimidinone) (3 and 5): A mixture of aromatic aldehyde (1)
(2 mmol), 4,6-dihydroxypyrimidine
(2) or 2,4-dihydroxy-6-
Refinement method
aminopyrimidine (4) (4 mmol) and TEBAC (0.15 g) in H20 (10 ml)
was stirred for 6-14 h at 90°C, then cooled to room temperature. The
crystalline powder formed was collected by filtration, washed with
water and recrystallised from DMF and dried at 120°C in vacuo to
give pure 3 or 5.
5,5 '-(3-nitrophenylmethylene)bis{ 6-hydroxypyrimidine-4(3H)-one]
(3a): M.p. 266-268°C. IR: v/cm-I 3500-2400, 1684, 1610, 1560,
1441, 1382, 1350, 1288, 1220, 1140, 1095, 1059,927,898,867,823,
789, 756, 721, 694. IH NMR (DMSO-d6): /) 6.25 (lH, s, CH), 7.48-
7.56 (2H, ill, ArH), 7.78 (lH, s, ArH), 8.03 (lH, d, J = 7.6 Hz, ArH),
8.21 (2H, s, 2 x C2-H), 12.65 (4H, br., s, 2 x OH, 2 x NH). Found:
C, 50.56; H, 3.02; N, 19.45. Calcd for CIsHllNs06: C, 50.43; H, 3.10;
N,19.60%.
Data/restra ints/pa ra meters
Goodness-of-fit on F2
Final R indices [1>2 sigma(l)]
R indices (all data)
1.058
R' = 0.0571, WR2= 0.1538
R' = 0.0994, WR2= 0.1920
0.439 and -0.482 eA-3
Largest diff. peak and hole
A reasonable mechanism for the formation of the products
3 is outlined in Scheme 3. The reaction occurs by an initial
formation of a Knoevenagel condensation product, from the
aromatic aldehyde 1 and 4,6-dihydroxypyrimidine
addition than occurs between the Knoevenagel condensation
2. Michael
5,5 '-(4-bromophenylmethylene)bis (6-hydroxypyrimidine-4 (3H)-
one] (3b): M.p. 258-260°C. IR: v/cm-I 3200-2500, 1653, 1558,
1487, 1448, 1397, 1294, 1243, 1134, 1096, 1073, 1009, 916, 845,
793, 698. IH NMR (DMSO-d6): /) 6.13 (lH, s, CH), 6.94 (2H, d,
J= 8.4 Hz, ArH), 7.39 (2H, d, J= 8.4 Hz, ArH), 8.14 (2H, s, 2 x
C2-H), 12.59 (4H, br., s, 2 x OH, 2 x NH). Found: C, 46.28; H, 2.91;
N, 14.17. Calcd for CIsHllBrN404: C, 46.06; H, 2.83; N, 14.32%.
5,5'-(2 -nitrophenylmethylene )bis (6-hydroxypyrimidine-4 (3H)-
one] (3c): M.p. > 300°C. IR: v/cm-I 3200-2500, 1652, 1620, 1566,
1522, 1470, 1431, 1386, 1361, 1308, 1250, 1234, 1098, 1061, 903,
855, 835, 804, 780, 724. IH NMR (DMSO-d6): /) 6.36 (lH, s, CH),
7.22 (lH, d, J = 7.6 Hz, ArH), 7.39 (lH, d, J = 7.6 Hz, ArH), 7.52
(lH, d, J= 7.6 Hz, ArH), 7.65 (lH, d, J= 7.6 Hz, ArH), 8.10 (2H,
s,2 x C2-H), 12.23 (4H, br., s, 2 x OH, 2 x NH). Found: C, 50.32;
H, 3.04; N, 19.34. Calcd for CIsHllNs06: C, 50.43; H, 3.10; N, 19.60%.
5,5 '-(4-hydroxyphenylmethylene)bis{ 6-hydroxypyrimidine-4(3H)-
one] (3d): M.p. > 300°C. IR: v/cm-I 3500-2500, 1674, 1620, 1557,
1512, 1445, 1391, 1291, 1243, 1173, 1095, 1060,912,837,793,775.
IH NMR (DMSO-d6): /) 6.07 (lH, s, CH), 6.60 (2H, d, J = 8.0 Hz,
product and another 4,6-dihydroxypyrimidine
isomerisation to give product 3.
In summary, the conversion of aromatic aldehydes and 4,6-
dihydroxypyrimidine or 2,4-dihydroxy-6-aminopyrimidine
into 5,5'-( arylmethylene )bis[ 6-hydroxypyrimidine-4(3H)-one]s
and 5,5'-(arylmethylene )bis[ 6-aminopyrimidine-2,4(1 H,3H)
-dione]s can be efficiently performed in water as a solvent
using a catalytic amount ofTEBAC. Compared to the previous
methods, this method has the advantages of good yields,
low cost, simple operation and an environmentally
procedure.
2 followed by
benign
Experimental
Melting points are uncorrected. IR spectra were recorded on a
Tensor 27 spectrometer in KEr with absorptions in cm-I. IH NMR
spectra were determined on a Bruker-400 MHz spectrometer using
DMSO-d6 solutions. Chemical shifts are expressed in ppm downfield
from internal tetramethylsilane. Microanalyses were carried out on
a Perkin-Elmer 2400 II elemental analyser. X-ray diffraction was
recorded on a Smart-1000 diffractometer.
ArH), 6.76 (2H, d, J
= 8.0 Hz, ArH), 8.10 (2H, s, 2 x C2-H), 9.07
(1H, s, OR), 12.52 (4H, br., s, 2 x OH, 2 x NH). Found: C, 55.02;
H, 3.61; N, 17.29. Calcd for CISH12N40S:C, 54.88; H, 3.68; N, 17.07%.
o
Ar
~-c£Q
HN
I
H
1
•
HNYOH
~
/';\
OH
~~
N
N
OH
2
y tAr
n
rO
HN
~
I
~H
9'
HN
~
I
I
~H
9 '
N
1 N
0
N
OH HO N
OH
3
Scheme
3

JOURNAL OF CHEMICAL RESEARCH 2008 721
5,5'-(3,4 -dichlorophenylmethylene )bis {6-hydroxypyrimidine-
4(3H)-one] (3e): M.p. 275-276°C. IR: v/cm-I 3500-2500, 1668,
1560, 1470, 1429, 1388, 1294, 1232, 1134, 1096, 1059, 1029,921,
808,791, 747, 725. IH NMR (DMSO-d6): /)6.14 (lH, s, CH), 6.99
(lH, d,J= 8.4 Hz,ArH), 7.14 (lH, s,ArH), 7.47 (lH, d,J= 8.4 Hz,
ArH), 8.17 (2H, s, 2 x C2-H), 12.63 (4H, br., s, 2 x OH, 2 x NH).
Found: C, 47.18; H 2.75; N, 14.83. Ca1cd for CIsHIOC12N404:
C, 47.27; H, 2.64; N, 14.70%.
5,5'-( 4-nitrophenylmethylene )bis (6-hydroxypyrimidine-4 (3H)-
one] (31): M.p. 257-259°C. IR: v/cm-13200-2500, 1672, 1632, 1558,
1529,1437,1388,1345,1291,1138,1095,1058,911,854,830,794,
764, 724. IH NMR (DMSO-d6): /) 6.25 (lH, s, CH), 7.27 (2H, d,
J= 8.8 Hz, ArH), 8.10 (2H, d,J= 8.8 Hz, ArH), 8.20 (2H, s,2 x C2-H),
12.66 (4H, br., s, 2 x OH, 2 x NH). Found: C 50.35; H 2.95;
N 19.43. Ca1cd for CIsHllNs06: C 50.43; H 3.10; N 19.60%.
5,5 '-(3-nitrophenylmethylene)bis{ 6-aminopyrimidine-2, 4(1H, 3H)-
dione] (5a): M.p. > 300°C. IR: v/cm-13421, 3311, 3242, 3189, 3074,
2988, 1699, 1623, 1592, 1539, 1458, 1393, 1338, 1290, 1234, 1192,
We are grateful to the "Surpassing Project" Foundation of
Jiangsu Province and the Foundation of the Key Laboratory
of Biotechnology on Medical Plants of Jiangsu Province for
financial support.
Received 21 April 2008; accepted 25 October 2008
Paper 08/5229 doi: 10.3184/030823408X390190
Published online: 17 December 2008
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IH NMR (DMSO-d6):
/)6.01 (4H, br., s, 2 x NH2), 6.25 (lH, s, CH), 7.59 (lH, t, J = 8.0 Hz,
ArH), 7.79 (lH, d, J= 7.6 Hz, ArH), 7.08 (lH, d, J= 8.0 Hz, ArH),
8.23 (lH, s,ArH), 10.07 (2H, br., s, 2 x NH), 10.44 (2H, br., s, 2 x NH).
Found: C, 46.75; H, 3.52; N, 25.17. Ca1cd for CIsH13N706: C,46.52;
H, 3.38; N, 25.32%.
7
8
9
R. Mitsuya, R. Yarchoan and S. Broder, Science, 1990,249, 1533.
5,5 '-(4-nitrophenylmethylene)bis{ 6-aminopyrimidine-2, 4(1H, 3H)-
dione] (5b): M.p. > 300°C. IR: v/cm-13444, 3312, 3167,1708,1641,
1624,1600,1532,1518,1457,1403,1351,1233,1175,1108,1050,871,
829,763,737,706. IH NMR (DMSO-d6): /)5.98 (4H, br., s, 2 x NH2),
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6.20 (lH, s, CH), 7.64 (2H, d, J
= 8.0 Hz, ArH), 8.17 (2H, d,
J = 8.0 Hz, ArH), 10.07 (2H, br., s, 2 x NH), 10.44 (2H, br., s, 2 x NH).
Found: C, 46.43; H, 3.46; N, 25.16. Ca1cd for CIsH13N706: C,46.52;
H, 3.38; N, 25.32%.
5,5 '-(2 -chlorophenylmethylene)bis
{6-aminopyrimidine-2,
4
(1H,3H)-dione] (5c): M.p. > 300°C. IR: v/cm-I 3365,3170, 1714,
1654,1634,1595,1455,1391,1168,1092,1024,886,775.IHNMR
(DMSO-d6): /)5.31 (lH, s, CH), 6.70 (4H, br., s, 2 xNH2), 7.03-7.07
(2H, ill, ArH), 7.16 (lH, d,J= 8.0 Hz, ArH), 7.25 (lH, t, J= 8.0 Hz,
ArH), 10.33 (2H, br., s, 2 x NH), 10.55 (2H, br., s, 2 x NH). Found:
C, 47.97; H, 3.53; N, 22.48. Calcd for CIsH13ClN604: C, 47.82; H,
3.48; N 22.31%.
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{6-aminopyrimidine-2,
4
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1635, 1551, 1529, 1522, 1489, 1457, 1393, 1296, 1240, 1179, 1093,
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IH NMR (DMSO-d6): /)5.28 (lH, s, CH), 6.17
(4H, br., s, 2 x NH2), 7.09 (2H, d, J = 8.4 Hz, ArH), 7.25 (2H, d,
J = 8.4 Hz, ArH), 10.07 (2H, br., s, 2 x NH), 10.52 (2H, br., s, 2 x NH).
Found: C 48.02; H 3.35; N 22.19. Ca1cdfor CIsH13ClN604: C,47.82;
H, 3.48; N, 22.31%.
5,5 '-(3 -chlorophenylmethylene)bis
{6-aminopyrimidine-2,
4
29 C.J. Li, Chern. Rev., 1993,93,2023.
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1658, 1623, 1523, 1456, 1394, 1217, 1180, 1154, 1096, 807, 784.
IH NMR (DMSO-d6): /)5.31 (lH, s, CH), 6.70 (4H, br., s, 2 x NH2),
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= 8.0 Hz, ArH), 7.25 (lH, t,
J = 8.0 Hz, ArH), 10.33 (2H, br., s, 2 x NH), 10.53 (2H, br., s, 2 x NH).
Found: C, 47.73; H, 3.34; N, 22.37. Calcd for CIsH13ClN604: C,
47.82; H, 3.48; N, 22.31 %.
1499.
X-ray crystal analysis of3c
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X-ray diffraction data were collected on a BRUKER SMART 1000
CCD detector with graphite-monochromatised Mo-Ka radiation
(A. = 0.71073 A) for compound 3c. The structures have been solved
by direct methods using the program SHELXL 9740 and Fourier
difference techniques. Refinement has been by full-matrix 1east-
squares method on F2 using SHELXL 97.41CCDC 705256 contains
the supplementary crystallographic data for this paper. The data can
be obtained free of charge from the Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/dataJequest.cif.
40 G.M. She1drick, SHELXL-97, Program for the Solution of Crystal
Structures University of Gottingen, 1997.
41 G.M. She1drick, SHELXL-97, Program for the Refinement of Crystal
Structures University of Gottingen, 1997.