(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 as a simple and efficient catalyst in Biginelli reaction

Article abstract of DOI:10.1002/aoc.3590

A highly efficient and facile procedure for the one-pot three-component synthesis of 3,4-dihydropyrimidin-2-(1H)ones/thiones from the one-pot condensation of aldehyde, β-dicarbonyl compound and urea/thiourea was developed. The methodology is applicable to

Full text of DOI:10.1002/aoc.3590

Received: 17 July 2016
DOI 10.1002/aoc.3590
Accepted: 28 July 2016
F U L L PA P E R
(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 as a simple and
efficient catalyst in Biginelli reaction
*
Xiang Zhang | Xiaoyu Gu | Yuhua Gao | Shipeng Nie | Hongfei Lu
School of Environment and Chemical Engineering,
A highly efficient and facile procedure for the one‐pot three‐component synthesis of
3,4‐dihydropyrimidin‐2‐(1H)ones/thiones from the one‐pot condensation of alde-
hyde, β‐dicarbonyl compound and urea/thiourea was developed. The methodology
is applicable to a wide range of substrates with high yield in the presence of
(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2. The complex is an air‐stable, envi-
ronmentally friendly and recoverable catalyst and can efficiently catalyze the
Biginelli reaction. The catalyst has high catalytic efficiency with low catalyst load-
ing, and can be recycled ten times with only a small loss of activity.
Jiangsu University of Science and Technology,
Zhenjiang 212003, People's Republic of China
Correspondence
Hongfei Lu, School of Environment and Chemical
Engineering, Jiangsu University of Science and
Technology, Zhenjiang, 212003, People's Republic
of China.
Email: zjluhf1979@hotmail.com
KEYWORDS
Biginelli reaction, dihydropyrimidinones (DHPMs), metal complex, multi‐component
reactions
1
|
INTRODUCTION
obtained. Other catalysts such as PPh3,[16] graphite[17] and
trypsin[18] can catalyze the Biginelli reaction effectively. At
As a one‐pot three‐component reaction, the Biginelli reaction
was reported by Petro Biginelli in 1893.[1] The Biginelli reac-
tion offers an efficient way to access multi‐functionalized
3,4‐dihydropyrimidin‐2‐(1H)ones (DHPMs) and related het-
erocyclic compounds. DHPMs have a wide spectrum of bio-
logical activities, such as antiviral, antitumor, antibacterial,
anticytotoxin, anti‐inflammatory and antihypertensive prop-
erties.[2] Several alkaloids obtained from marine sources con-
tain the dihydropyrimidine nucleus, and these alkaloids show
some interesting biological activities.[3] Thus, the synthesis
of DHPMs has been of much importance in recent decades.
A strong acidic catalyst was employed in the original
Biginelli reaction, but the yields of products (DHPMs) were
low. In order to improve the yields of products, several kinds
of catalysts were applied to the reaction process. A Lewis
acid was a common catalyst for the Biginelli reaction, such
the same time, more and more conditions were applied to
the Biginelli reaction, such as microwave irradiation,[19]
ultrasound irradiation[20] and solvent‐free conditions,[21] and
all of these methods have been achieved giving high yields
of DHPMs.
Bismuth is the only stable heavy metal element with
less toxicity and radioactive in nature, and its compounds
have been of great value as metal catalysts in organic syn-
thesis since the discovery of their catalytic activity.[22]
Some bismuth salts have been applied to the Biginelli reac-
tion, such as BiCl3,[23] Bi(OTf)3,[24] Bi(NO3)3⋅5H2O[25] and
BiONO3.[26] All of these were successfully applied for the
synthesis of DHPMs. However, there are problems with
these methods, such as use of toxic solvent, complex oper-
ation, requirement of a large amount of catalyst and diffi-
culty in recycling the catalyst. A new bismuth complex
has been studied in our laboratory. The complex is highly
stable in air, and has been successfully applied in the
one‐pot three‐component Biginelli reaction. The complex
can catalyze a wide range of substrates in ethanol and be
recycled ten times with only a small loss of activity. High
yields of products can be obtained under simple operation
in this method, and the amount of the catalyst required is
low (only 1 mol%).
as SbCl3,[4] CaF2,[5] Fe3O4/SMPA,[6] Cu(OTf)2,[7] ZnI2
[8]
and ZrCl4/ZrOCl2. Many ionic liquids have been applied to
the Biginelli reaction, including [Et3NSO3H]HSO4,[9]
[Hmim]HSO4,[10] [cmmim][BF4][11] and sulfonic acid‐func-
tionalized Brønsted acidic ionic liquids.[12] Metal–organic
complexes, such as bis[(L)prolinato‐N,O]Zn,[13] [Gmim]
ClCu(II)[14] and CPs/MOFs,[15] were used as catalysts for
the Biginelli reaction and high yields of DHPMs were
Appl. Organometal. Chem. 2016; 1–10
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
1

2
ZHANG ET AL.
2
|
RESULTS AND DISCUSSION
yield of 4a (Table 1, entry 20) was obtained (95%). When
complexes of bismuth(III) chloride with oxygen donor
ligands (Table 1, entries 21 and 22) or constrained thioether
ligand (Table 1, entry 23) catalyzed the model reaction, the
yield of 4a was no more than 60%. These results show that
the 6‐hydroxypurine ligand also played an important role in
the catalysis process. The Bi complex (C5H6N4O)
(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 was a suitable catalyst
for the one‐pot three‐component Biginelli reaction.
As evident from Table 2, with ethanol as the solvent in the
model reaction, the yield of 4a was 95% (Table 2, entry 6).
When the solvent was changed to methanol and acetonitrile,
the yield was reduced to 80 and 84%, respectively (Table 2,
entries 1 and 2). And the yield of 4a was less than 50%
when ethyl acetate, methylene chloride or water served as sol-
vent (Table 2, entries 3–5). The amount of catalyst loading that
exhibited the best performance in terms of yield was further
examined. It was found that 1 mol% (C5H6N4O)(C5H5N4O)3
(C5H4N4O)[Bi2Cl11]Cl2 achieved a yield of 4a of 95%. When
the catalyst loading was lower than 1 mol%, the yield of 4a
increased with increasing amount. There was no further
increase in the yield of 4a when the catalyst loading was over
1 mol%. Thus, 1 mol% (C5H6N4O)(C5H5N4O)3(C5H4N4O)
[Bi2Cl11]Cl2 was suitable for the reaction.
At the outset of our investigations, a selection of Lewis acids
and metal complexes were applied to the model reaction
(benzaldehyde (1a), urea (2a) and ethyl acetoacetate (3a))
under prototypical reaction conditions (1 mol%, reflux,
6 h), as summarized in Table 1. Lewis acids could catalyze
this reaction alone, but the yields of 4a were all less than
60% (Table 1, entries 2–4, 6, 8, 10 and 12). When metal–
piperazine complexes were used as catalysts of the model
reaction (Table 1, entries 5, 7, 9, 11 and 14), the yields of
4a were all over 60%, and an 87% yield of 4a was obtained
under catalysis with Bi–piperazine complex (Table 1, entry
14). When the ligand of the Bi complex was replaced with
other nitrogenous heterocyclic compounds (Table 1, entries
13, 15–20), all these Bi complexes could catalyze the reac-
tion, and the yields were all over 70%. At the same time,
when catalyzed by Bi–6‐hydroxypurine complex,
(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2, the highest
TABLE 1 Optimization of catalystsa
3
| EXPERIMENTAL
Entry
Metal salt
Ligand
Yield (%)b
3.1 | Catalyst
1
—
—
—
—
—
0
45
62
41
70
53
75
33
64
52
72
58
71
87
83
84
86
81
82
95
30
49
60
2
AlCl3
SnCl4
FeCl3
6‐Hydroxypurine (1.36 g, 10 mmol), BiCl3 (2.15 g,
6.8 mmol) and 35% aqueous HCl (3 ml) were mixed,
3
4
TABLE 2 Optimization of Biginelli reaction conditionsa
5
Piperazine
—
6
NiCl2
MnCl2
SbCl3
BiCl3
7
Piperazine
—
8
9
Piperazine
—
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Piperazine
—
Entry
Solvent
MeOH
Catalyst amount (mol%)
Yield (%)b
Piperidine
Piperazine
Imidazole
1
1
80
84
42
39
54
95
23
49
71
94
95
2
MeCN
1
3
Ethyl acetate
Dichloromethane
H2O
1
2‐Methylimidazole
Dalfampridine‐d4
Indoline
4
1
5
1
6
EtOH
1
Tetrahydroquinoline
6‐Hydroxypurine
Tetrahydrofuran
Diethyl carbitol
o‐C6H4(SMe)2
7
EtOH
0.5
0.7
0.9
1.2
1.4
8
EtOH
9
EtOH
10
11
EtOH
EtOH
aReaction conditions: 1a (1 mmol), 3a (1 mmol), 2a (1.5 mmol), catalyst (1 mol
aReaction conditions: 1a (1 mmol), 3a (1 mmol), 2a (1.5 mmol), solvent (5 ml),
%), solvent (EtOH, 5 ml), refluxing, 6 h.
refluxing, 6 h.
bYields refer to isolated products.
bYields refer to isolated products.

ZHANG ET AL.
3
dissolved in water (30 ml) and heated to 80°C to form a clear
solution. The mixture was cooled slowly to room tempera-
ture. Single crystals of (C5H6N4O)(C5H5N4O)3(C5H4N4O)
[Bi2Cl11]Cl2 were collected after 7 days (Scheme 1). The
crystal structure of the catalyst is shown in Figure 1.
TABLE 3 Three‐component (C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11
]
Cl2‐catalyzed Biginelli reaction with various aldehydesa
3.2 | Biginelli reaction: General procedure
Entry
R1
Product
Yield (%)b
A mixture of aldehyde (1.0 mmol), β‐dicarbonyl compound
(1.0 mmol), urea/thiourea (1.5 mmol), (C5H6N4O)
(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 (0.1 mmol) and EtOH
(5 ml) was heated to reflux. The course of the reaction was
monitored by TLC and complete disappearance of the raw
materials was observed within 6 h. The mixture was diluted
with EtOH (10 ml) and the catalyst was isolated by simple
decantation. After evaporation of the solvent, the crude prod-
uct was purified by either crystallization (EtOH) or column
chromatography (silica gel, EtOAc–petroleum ether). Known
products were identified by comparing their spectral data
with those of authentic samples. Substrates, products and
yields are summarized in Table 3.
Isomerization of the products derived from the condensa-
tion reactions involving salicyladehyde (4c, 4u) was found in
experiments. Scheme 2 shows the molecular structure.
Simultaneously, urea was replaced by thiourea or deriva-
tives of urea. The results are shown in Table 4. The yields of
products when using thiourea were lower than when using
urea. Yields of aromatic aldehydes carrying electron‐with-
drawing groups reacting with thiourea were 78–82% (4 t,
4u and 4×), and the yields of products of aromatic aldehydes
1
2
3
4
5
6
7
8
9
10
C6H6
4a
4b
4c
90
91
92
81
96
96
93
83
96
75
2‐ClC6H6
2‐OHC6H6
3‐NO2C6H6
4‐CH3C6H6
4‐OMeC6H6
4‐PhC6H6
4d
4e
4f
4 g
4 h
4i
4‐NO2C6H6
3,4‐2OMeC6H6
4j
11
12
13
14
15
16
Me
Et
4 k
4 l
91
91
89
87
86
87
Pr
4 m
4n
Bu
Am
4o
4p
17
18
4q
4r
85
90
aReaction conditions: aldehyde (1 mmol), ethyl acetoacetate (1 mmol), thiourea
(1.5 mmol), catalyst (1 mol%), solvent (EtOH, 5 ml), refluxing, 6 h.
bYields refer to isolated products.
SCHEME 1 Structure of catalyst.
SCHEME 2 Isomerization of DHPMs to diazatricyclic compounds.
carrying electron‐donating groups reached 86, 85 and 83%
for 4v, 4w and 4y, respectively. As products of aliphatic alde-
hydes, yields of 4z, 4a' and 4b' reached 73–80%. As substi-
tutes for urea, methylurea and ethylurea reacted with
benzaldehyde or acetaldehyde, and the yields of 4c', 4d',
4e' and 4f' were 77–83% which were lower than those when
using urea (4a, 95%; 4 k, 91%).
The scope of the method was extended to β‐dicarbonyl
compounds. As evident from Table 5, β‐carbonyl ester and
FIGURE 1 Crystal structures of catalyst.

4
ZHANG ET AL.
TABLE 4 Three‐component (C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2‐catalyzed Biginelli reaction with various aldehydes, thiourea or derivatives of
ureaa
Entry
Aldehyde
Thiourea/urea
Product
Yield (%)b
1
2
R1 = C6H6
2‐ClC6H6
2‐OHC6H6
4‐CH3C6H6
4‐OMeC6H6
4‐ClC6H6
4‐PhC6H6
Me
R2 = H, X = S
4 s
4 t
4u
4v
85
80
82
86
85
81
83
75
73
80
3
4
5
4w
4×
4y
6
7
8
4z
9
Am
4a'
4b'
10
11
12
13
14
C6H6
Me
R2 = Me, X = O
4c'
4d'
4e'
4f'
86
85
80
87
R
2 = Et, X = O
R2 = Me, X = O
2 = Et, X = O
R
aReaction conditions: aldehyde (1 mmol), ethyl acetoacetate (1 mmol), thiourea (1.5 mmol), catalyst (1 mol%), solvent (EtOH, 5 ml), refluxing, 6 h.
bYields refer to isolated products.
TABLE 5 Three‐component (C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2‐catalyzed Biginelli reaction with various β‐carbonyl esters/ketonesa
Entry
Aldehyde
β‐Carbonyl ester/ketone
Product
Yield (%)b
1
2
3
4
5
R1 = C6H6
R3 = Me, R4 = OMe
4 g'
4 h'
4i'
96
93
85
80
79
R3 = Me, R4 = Oi‐Pr
R3 = Me, R4 = Me
R3 = Ph, R4 = Ph
4j'
4 k'
6
4 l'
75
7
8
R
1 = Me
R3 = Me, R4 = OMe
3 = Me, R4 = Oi‐Pr
4 m'
4n'
93
90
R
aReaction conditions: aldehyde (1 mmol), β‐carbonyl ester/ketone (1 mmol), urea (1.5 mmol), catalyst (1 mol%), solvent (EtOH, 5 ml), refluxing, 6 h.
bYields refer to isolated products.
β‐carbonyl ketone could afford the desired products
4 g'–n'. For β‐carbonyl ester, yields of 4 g' (96%) and
4 h' (93%) were similar to that of 4a (95%) and yields of
4 m' and 4n' were similar to that of 4 k, 93 and 90%,
respectively. As substitutes for ethyl acetoacetate,
β‐carbonyl ketones could be used as substrates for the

ZHANG ET AL.
5
Biginelli reaction, and yields of products were 75–85%.
The yields when using β‐carbonyl ketones with chain struc-
tures (4i', 85%; 4j', 80%) were higher than when using
annular β‐carbonyls (4 k', 79%; 4 l', 75%).
3.3 | Mechanism
Folkers and co‐workers[28] suggested the mechanism for the
formation of DHPMs via an acylimine intermediate, and the
following mechanism has been proposed (Scheme 3). The
mechanism consists of an initial step of a reaction between
the respective aldehydes (A) and urea/thiourea (B) forming
their corresponding hemiaminals, N‐(1‐hydroxybenzyl/
substituted benzyl)urea/thiourea (D), via standard nucleo-
philic addition reaction. D interacts with the Bi complex,
forming a highly reactive intermediate (E). At the same time,
the respective β‐ketoesters (C) or possibly their enol forms
activated by the Bi complex (F) attack E to afford open‐chain
intermediates (G). G after further nucleophilic addition even-
tually undergoes dehydration to furnish the DHPMs/DHPM
thiones (H).
FIGURE 2 Reusability cycles of catalyst.
4
| CONCLUSIONS
We have developed a facile, convenient and environmentally
friendly one‐pot three‐component synthetic method for
DHPMs. As an accessible, low‐toxicity, stable and recyclable
catalyst,
(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2
3.4 | Recyclability and activity of catalyst
could catalyze the Biginelli reaction efficiently with low cat-
alyst loading and be recycled ten times with only a small loss
of activity. The present protocol offers a simple, inexpensive
and versatile approach to the synthesis of sterically demand-
ing DHPMs.
In order to examine the recyclability and activity of the cata-
lyst, the one‐pot three‐component Biginelli reaction of
benzaldehyde (1a), urea (2a) and ethyl acetoacetate (3a) cat-
alyzed by (C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 in
refluxing ethanol was used as a model reaction. The reaction
mixture was stirred under TLC analysis until benzaldehyde
disappeared completely. After completion of the reaction,
the catalyst was recovered by filtration and washed with hot
ethanol. The catalyst was recovered without significant loss.
The recovered catalyst was reused directly. As shown in
Figure 2, the catalyst was recycled ten times with only a small
loss of activity (isolated yield only slightly declined from 95
to 85%).
5
| CHARACTERIZATION DATA
Unless otherwise stated, all reagents and solvents were used
without further purification. Flash column chromatography
was performed using silica gel (200–300 mesh) under pres-
sure. Analytical TLC was carried out using GF254 commer-
cial silica gel plates. Visualization of the developed
chromatogram was performed by UV absorption or aqueous
1
KMnO4. All H NMR spectra were recorded in DMSO‐d6
or CDCl3 solution. H NMR spectra were referenced inter-
1
nally to the residual proton resonance in DMSO (2.5 ppm)
and CDCl3 (7.26 ppm).
5.1 | Ethyl 6‐Methyl‐2‐oxo‐4‐phenyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4a)[5]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.21
(s, 1H), 7.75 (s, 1H), 7.36–7.20 (m, 5H), 5.15 (d,
J = 3.2 Hz, 1H), 3.98 (q, J = 7.1 Hz, 2H), 2.25 (s, 3H),
1.09 (t, J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 260.1. Anal.
Calcd for C14H16N2O3 (260.12) (%): C, 64.60; H, 6.20; N,
10.76. Found (%): C, 64.48; H, 6.11; N, 10.81.
SCHEME
3
Mechanism for the (C5H6N4O)(C5H5N4O)3(C5H4N4O)
[Bi2Cl11]Cl2‐catalyzed Biginelli reaction.

6
ZHANG ET AL.
5.2 | Ethyl 4‐(2‐Chlorophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4b)[29]
5.7 | Ethyl 4‐(Biphenyl‐4‐yl)‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4 g)[29]
1
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.28
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.26
(s, 1H), 7.72 (s, 1H), 7.43–7.24 (m, 4H), 5.63 (d,
J = 2.7 Hz, 1H), 3.89 (q, J = 7.0 Hz, 2H), 2.30 (s, 3H),
0.99 (t, J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 294.1. Anal.
Calcd for C14H15ClN2O3 (294.08) (%): C, 57.05; H, 5.13; N,
9.50. Found (%): C, 56.87; H, 5.31; N, 9.65.
(s, 1H), 7.81 (s, 1H), 7.63 (t, J = 6.6 Hz, 4H), 7.41 (ddd,
J = 20.4, 16.3, 10.1 Hz, 5H), 5.20 (d, J = 2.5 Hz, 1H),
4.01 (q, J = 7.0 Hz, 2H), 2.27 (s, 3H), 1.13 (t, J = 7.0 Hz,
3H). MS (ESI, 70 eV): m/z = 336.1. Anal. Calcd for
C20H20N2O3 (336.15) (%): C, 71.41; H, 5.99; N, 8.33. Found
(%): C, 71.26; H, 5.85; N, 8.61.
5.3 | Ethyl 4‐(2‐Hydroxyphenyl)‐6‐methyl‐2‐oxo‐
1,2,3,4‐tetrahydropyri midine‐5‐carboxylate (4c)[29]
5.8 | Ethyl 4‐(4‐Nitrophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4 h)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 7.62
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.37
(s, 1H), 8.25–8.20 (m, 2H), 7.91 (s, 1H), 7.55–7.46 (m,
2H), 5.28 (d, J = 3.3 Hz, 1H), 3.99 (q, J = 7.1 Hz, 2H),
2.27 (s, 3H), 1.10 (t, J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/
z = 305.0. Anal. Calcd for C14H15N3O5 (305.1) (%): C,
55.08; H, 4.95; N, 13.76. Found (%): C, 55.40; H, 4.74; N,
14.09.
(s, 1H), 7.28–7.16 (m, 3H), 6.88 (ddd, J = 46.4, 26.4,
4.6 Hz, 2H), 4.47 (dd, J = 4.7, 2.9 Hz, 1H), 4.17 (p,
J = 3.7 Hz, 2H), 3.29–3.24 (m, 1H), 1.74 (s, 3H), 1.24 (t,
J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 276.1. Anal. Calcd
for C14H16N2O4 (276.11) (%): C, 60.86; H, 5.84; N, 10.14.
Found (%): C, 60.60; H, 5.51; N, 9.95.
5.4 | Ethyl 4‐(3‐Nitrophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4d)[29]
5.9 | Ethyl 4‐(3,4‐Dimethoxyphenyl)‐6‐methyl‐2‐oxo‐
1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate (4i)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.39
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.17
(s, 1H), 8.20–8.05 (m, 2H), 7.92 (s, 1H), 7.69 (ddd,
J = 19.6, 10.9, 4.6 Hz, 2H), 5.31 (d, J = 3.3 Hz, 1H),
4.16–3.83 (m, 2H), 2.28 (s, 3H), 1.10 (t, J = 7.1 Hz, 3H).
MS (ESI, 70 eV): m/z = 305.2. Anal. Calcd for
C14H15N3O5 (305.1) (%): C, 55.08; H, 4.95; N, 13.76. Found
(%): C, 55.36; H, 4.78; N, 14.07.
(s, 1H), 7.69 (s, 1H), 6.99–6.60 (m, 3H), 5.10 (d,
J = 2.9 Hz, 1H), 4.00 (q, J = 7.0 Hz, 2H), 3.71 (s, 6H),
2.24 (s, 3H), 1.12 (t, J = 7.1 Hz, 3H). MS (ESI, 70 eV):
m/z = 320.1. Anal. Calcd for C16H20N2O5 (320.14) (%): C,
59.99; H, 6.29; N, 8.74. Found (%): C, 60.09; H, 6.05; N,
8.78.
5.5 | Ethyl 6‐Methyl‐2‐oxo‐4‐p‐tolyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4e)[17]
5.10 | Ethyl 4‐(Furan‐2‐yl)‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4j)[29]
1
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.18
Taupe solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.26
(s, 1H), 7.71 (s, 1H), 7.12 (s, 4H), 5.10 (d, J = 2.9 Hz,
1H), 3.97 (q, J = 7.0 Hz, 2H), 2.26 (s, 3H), 2.24 (s, 3H),
1.10 (t, J = 7.0 Hz, 3H). MS (ESI, 70 eV): m/z = 274.1. Anal.
Calcd for C15H18N2O3 (274.13) (%): C, 65.68; H, 6.61; N,
10.21. Found (%): C, 65.79; H, 6.48; N, 9.97.
(s, 1H), 7.77 (s, 1H), 7.56 (d, J = 0.8 Hz, 1H), 6.36 (dd,
J = 3.0, 1.8 Hz, 1H), 6.09 (d, J = 3.1 Hz, 1H), 5.20 (d,
J = 3.3 Hz, 1H), 4.18–3.86 (m, 2H), 2.23 (s, 3H), 1.14 (t,
J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 250.1. Anal. Calcd
for C12H14N2O4 (250.1) (%): C, 57.59; H, 5.64; N, 11.19.
Found (%): C, 57.46; H, 6.01; N, 8.91.
5.6 | Ethyl 4‐(4‐Methoxyphenyl)‐6‐methyl‐2‐oxo‐
1,2,3,4‐tetrahydropyri midine‐5‐carboxylate (4f)[17]
5.11 | Ethyl 4,6‐Dimethyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 k)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.16
1
(d, J = 1.3 Hz, 1H), 7.72–7.63 (m, 1H), 7.20–6.82 (m, 4H),
5.09 (d, J = 3.3 Hz, 1H), 3.98 (q, J = 7.1 Hz, 2H), 3.72 (s,
3H), 2.24 (s, 3H), 1.11 (t, J = 7.1 Hz, 3H). MS (ESI,
70 eV): m/z = 290.2. Anal. Calcd for C15H18N2O4 (290.13)
(%): C, 62.06; H, 6.25; N, 9.65. Found (%): C, 62.09; H,
6.58; N, 9.47.
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.00
(s, 1H), 7.23 (s, 1H), 4.08 (tdd, J = 17.0, 7.0, 3.5 Hz, 3H),
2.16 (s, 3H), 1.19 (t, J = 7.1 Hz, 3H), 1.09 (t, J = 6.2 Hz,
3H). MS (ESI, 70 eV): m/z = 198.1. Anal. Calcd for
C9H14N2O3 (198.1) (%): C, 54.53; H, 7.12; N, 14.13. Found
(%): C, 54.64; H, 7.03; N, 14.44.

ZHANG ET AL.
7
5.12 | Ethyl 4‐Ethyl‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 l)[29]
(m, 3H), 2.17 (d, J = 2.2 Hz, 3H), 1.47–1.06 (m, 6H),
0.90–0.67 (m, 6H). MS (ESI, 70 eV): m/z = 240.2. Anal.
Calcd for C12H20N2O3 (240.15) (%): C, 59.98.; H, 8.39; N,
11.66. Found (%): C, 60.15; H, 8.61; N, 11.42.
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.94
(s, 1H), 7.31 (s, 1H), 4.14–3.98 (m, 3H), 2.17 (s, 3H),
1.50–1.31 (m, 2H), 1.19 (td, J = 7.1, 2.7 Hz, 3H), 0.79 (t,
J = 7.4 Hz, 3H). MS (ESI, 70 eV): m/z = 212.2. Anal. Calcd
for C10H16N2O3 (212.12) (%): C, 56.59; H, 7.60; N, 13.20.
Found (%): C, 56.47; H, 7.69; N, 13.54.
5.18 | Ethyl 4‐Cyclohexyl‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4r)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.89
(s, 1H), 7.29 (d, J = 1.5 Hz, 1H), 4.13–3.99 (m, 2H), 3.93
(t, J = 3.8 Hz, 1H), 2.17 (s, 3H), 1.64 (dd, J = 33.1,
10.0 Hz, 4H), 1.32 (dd, J = 19.3, 16.4 Hz, 2H), 1.19 (t,
J = 7.1 Hz, 3H), 1.09 (dd, J = 23.5, 10.5 Hz, 4H), 0.85 (dt,
J = 12.3, 7.5 Hz, 1H). MS (ESI, 70 eV): m/z = 266.1. Anal.
Calcd for C14H22N2O3 (266.16) (%): C, 63.13; H, 8.33; N,
10.52. Found (%): C, 63.35; H, 8.13; N, 10.37.
5.13 | Ethyl 6‐Methyl‐2‐oxo‐4‐propyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 m)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.95
(s, 1H), 7.35 (s, 1H), 4.06 (pd, J = 7.2, 3.6 Hz, 3H), 2.16
(s, 3H), 1.45–1.22 (m, 4H), 1.19 (t, J = 7.1 Hz, 3H), 0.85
(t, J = 7.0 Hz, 3H). MS (ESI, 70 eV): m/z = 226.1. Anal.
Calcd for C11H18N2O3 (226.13) (%): C, 58.39; H, 8.02; N,
12.38. Found (%): C, 58.09; H, 7.89; N, 12.73.
5.19 | Ethyl 6‐Methyl‐4‐phenyl‐2‐thioxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 s)[17]
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.36
(s, 1H), 9.67 (d, J = 1.6 Hz, 1H), 7.44–7.15 (m, 5H), 5.18 (d,
J = 3.7 Hz, 1H), 4.01 (q, J = 7.0 Hz, 2H), 2.30 (s, 3H), 1.16–
1.07 (m, 3H). MS (ESI, 70 eV): m/z = 276.0. Anal. Calcd for
C14H16N2O2S (276.09) (%): C, 60.85; H, 5.84; N, 10.14; S,
11.60. Found (%): C, 60.49; H, 5.88; N, 10.32; S; 11.73.
5.14 | Ethyl 4‐Butyl‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4n)[29]
White solid 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.95 (s,
1H), 7.34 (s, 1H), 4.06 (dddd, J = 17.9, 10.9, 7.1, 3.8 Hz,
3H), 2.16 (s, 3H), 1.45–1.21 (m, 6H), 1.19 (t, J = 7.1 Hz,
3H), 0.85 (t, J = 6.7 Hz, 3H). MS (ESI, 70 eV): m/
z = 240.2. Anal. Calcd for C12H20N2O3 (240.15) (%): C,
59.98.; H, 8.39; N, 11.66. Found (%): C, 60.23; H, 8.33; N,
11.85.
5.20 | Ethyl 4‐(2‐Chlorophenyl)‐6‐methyl‐2‐thioxo‐
1,2,3,4‐tetrahydropyri midine‐5‐carboxylate (4 t)[29]
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.38
(s, 1H), 9.62 (s, 1H), 7.52–7.24 (m, 4H), 5.64 (d, J = 3.2 Hz,
1H), 3.92 (q, J = 7.1 Hz, 2H), 2.33 (s, 3H), 1.06 (t,
J = 7.0 Hz, 3H). MS (ESI, 70 eV): m/z = 310.3. Anal. Calcd
for C14H15ClN2O2S (310.05) (%): C, 54.10; H, 4.86; N, 9.01;
S, 10.32. Found (%): C, 54.44; H, 4.72; N, 9.15; S, 10.18.
5.15 | Ethyl 6‐Methyl‐2‐oxo‐4‐pentyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4o)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.94
(s, 1H), 7.34 (s, 1H), 4.14–3.98 (m, 3H), 2.16 (s, 3H),
1.49–1.11 (m, 12H), 0.85 (t, J = 6.8 Hz, 3H). MS (ESI,
70 eV): m/z = 254.2. Anal. Calcd for C13H22N2O3 (254.16)
(%): C, 61.39.; H, 8.72; N, 11.01. Found (%): C, 61.17; H,
8.85; N, 10.94.
5.21 | Ethyl 4‐(2‐Hydroxyphenyl)‐6‐methyl‐2‐thioxo‐
1,2,3,4‐tetrahydro pyrimidine‐5‐carboxylate (4u)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.39
5.16 | Ethyl 6‐Methyl‐4‐isopropyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4p)[29p]
(dd, J = 5.1, 1.8 Hz, 1H), 9.17 (d, J = 1.7 Hz, 1H), 7.10
(dddd, J = 59.2, 52.6, 30.6, 4.8 Hz, 4H), 4.59 (dd, J = 5.2,
2.6 Hz, 1H), 4.04 (q, J = 7.1 Hz, 2H), 3.40 (d, J = 2.6 Hz,
1H), 1.89 (s, 3H), 1.07 (t, J = 7.1 Hz, 3H). MS (ESI,
70 eV): m/z = 292.1. Anal. Calcd for C14H16N2O3S
(292.09) (%): C, 57.52; H, 5.52; N, 9.58; S, 10.97. Found
(%): C, 57.31; H, 5.60; N, 9.81; S, 10.73.
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.91
(s, 1H), 7.31 (s, 1H), 4.14–4.00 (m, 2H), 3.95 (t,
J = 3.6 Hz, 1H), 2.17 (d, J = 6.9 Hz, 3H), 1.27–1.13 (m,
4H), 0.82 (d, J = 6.9 Hz, 3H), 0.74 (d, J = 6.8 Hz, 3H).
MS (ESI, 70 eV): m/z = 226.2. Anal. Calcd for
C11H18N2O3 (226.13) (%): C, 58.39; H, 8.02; N, 12.38.
Found (%): C, 58.46; H, 8.07; N, 12.66.
5.22 | Ethyl 6‐Methyl‐4‐p‐tolyl‐2‐thioxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4v)[17]
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.32
(s, 1H), 9.63 (d, J = 1.7 Hz, 1H), 7.12 (dd, J = 21.3, 8.1 Hz,
4H), 5.13 (d, J = 3.7 Hz, 1H), 4.01 (q, J = 7.1 Hz, 2H), 2.28
(d, J = 7.3 Hz, 6H), 1.11 (t, J = 7.1 Hz, 3H). MS (ESI,
5.17 | Ethyl 4‐sec‐Butyl‐6‐methyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4q)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 8.89
(d, J = 9.4 Hz, 1H), 7.27 (d, J = 39.9 Hz, 1H), 4.19–3.86

8
ZHANG ET AL.
70 eV): m/z = 290.1. Anal. Calcd for C15H18N2O2S (290.11)
(%): C, 62.04; H, 6.25; N. 9.65; S, 11.04. Found (%): C,
62.15; H, 6.11; N, 9.43; S, 11.21.
N, 10.36; S, 11.86. Found (%): C, 57.57; H, 8.35; N,
10.46; S, 11.69.
5.28 | Ethyl 4‐Cyclohexyl‐6‐methyl‐2‐thioxo‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4b')[29]
5.23 | Ethyl 4‐(4‐Methoxyphenyl)‐6‐methyl‐2‐thioxo‐
1,2,3,4‐tetrahydro pyrimidine‐5‐carboxylate (4w)[29]
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.15
(s, 1H), 9.31 (d, J = 2.5 Hz, 1H), 4.22–4.07 (m, 2H), 4.03 (t,
J = 4.3 Hz, 1H), 2.27 (s, 3H), 1.71 (dd, J = 29.0, 9.9 Hz, 4H),
1.50–1.32 (m, 2H), 1.26 (t, J = 7.1 Hz, 3H), 1.21–1.07 (m,
4H), 0.90 (t, J = 12.0 Hz, 1H). MS (ESI, 70 eV): m/
z = 282.5. Anal. Calcd for C14H22N2O2S (282.14) (%): C,
59.54; H, 7.85; N, 9.92; S, 11.35. Found (%): C, 59.69; H,
7.98; N, 10.00; S, 11.05.
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.31
(s, 1H), 9.62 (d, J = 1.7 Hz, 1H), 7.18–7.08 (m, 2H), 6.95–
6.85 (m, 2H), 5.11 (d, J = 3.7 Hz, 1H), 4.00 (q,
J = 7.1 Hz, 2H), 3.73 (s, 3H), 2.29 (s, 3H), 1.11 (t,
J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 306.4. Anal. Calcd
for C15H18N2O3S (306.1) (%): C, 58.80; H, 5.92; N, 9.14; S,
10.47. Found (%): C, 59.00; H, 6.17; N, 9.03; S, 10.11.
5.29 | Ethyl 1,6‐Dimethyl‐2‐oxo‐4‐phenyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4c')[29]
5.24 | Ethyl 4‐(4‐Chlorophenyl)‐6‐methyl‐2‐thioxo‐
1,2,3,4‐tetrahydropyri midine‐5‐carboxylate (4×)[29]
White solid. 1H NMR (400 MHz, CDCl3, δ, ppm): 7.33–7.29
(m, 1H), 7.28–7.22 (m, 4H), 5.73 (s, 1H), 5.39 (d, J = 2.3 Hz,
1H), 4.11 (q, J = 7.1 Hz, 2H), 3.23 (s, 3H), 2.52 (s, 3H), 1.19
(t, J = 7.1 Hz, 3H). MS (ESI, 70 eV): m/z = 274.2. Anal.
Calcd for C15H18N2O3 (274.13) (%): C, 65.68; H, 6.61; N,
10.21. Found (%): C, 65.79; H, 6.77; N, 10.00.
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.41
(s, 1H), 9.69 (s, 1H), 7.43 (d, J = 8.4 Hz, 2H), 7.22 (d,
J = 8.4 Hz, 2H), 5.16 (d, J = 3.4 Hz, 1H), 4.00 (q,
J = 6.9 Hz, 2H), 2.29 (s, 3H), 1.09 (t, J = 7.1 Hz, 3H). MS
(ESI, 70 eV): m/z = 310.0. Anal. Calcd for C14H15ClN2O2S
(310.05) (%): C, 54.10; H, 4.86; N, 9.01; S, 10.32. Found
(%): C, 54.33; H, 4.69; N, 9.21; S, 10.39.
5.30 | Ethyl 1‐Ethyl‐6‐methyl‐2‐oxo‐4‐phenyl‐1,2,3,4‐
tetrahydropyri midine‐5‐carboxylate (4d')[29]
5.25 | Ethyl 4‐(Biphenyl‐4‐yl)‐6‐methyl‐2‐thioxo‐
1,2,3,4‐tetrahydropyri midine‐5‐carboxylate (4y)[29]
White solid. 1H NMR (400 MHz, CDCl3, δ, ppm): 7.29 (dd,
J = 10.0, 4.1 Hz, 2H), 7.26–7.20 (m, 3H), 5.71 (d,
J = 7.4 Hz, 1H), 5.35 (d, J = 2.3 Hz, 1H), 4.09 (q,
J = 7.1 Hz, 2H), 3.89 (dt, J = 14.2, 7.1 Hz, 1H), 3.75 (dt,
J = 14.5, 7.1 Hz, 1H), 2.53 (s, 3H), 1.19 (dt, J = 14.3,
7.1 Hz, 6H). MS (ESI, 70 eV): m/z = 288.2. Anal. Calcd
for C16H20N2O3 (288.15) (%): C, 66.65; H, 6.99; N, 9.72.
Found (%): C, 66.91; H, 6.68; N, 9.70.
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.40
(s, 1H), 9.72 (d, J = 1.9 Hz, 1H), 7.73–7.57 (m, 4H), 7.50–
7.28 (m, 5H), 5.23 (d, J = 3.7 Hz, 1H), 4.04 (q,
J = 7.1 Hz, 2H), 2.32 (s, 3H), 1.14 (t, J = 7.1 Hz, 3H). MS
(ESI, 70 eV): m/z = 352.1. Anal. Calcd for C20H20N2O2S
(352.12) (%): C, 68.16; H, 5.72; N, 7.95; S, 9.10. Found
(%): C, 68.30; H, 5.49; N, 7.66; S, 9.30.
5.31 | Ethyl 1,4,6‐Trimethyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4e')[29]
5.26 | Ethyl 4,6‐Dimethyl‐2‐thioxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4z)[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 7.42
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm): 10.15
(s, 1H), 9.22 (s, 1H), 4.18–4.03 (m, 3H), 2.20 (s, 3H), 1.20 (t,
J = 7.1 Hz, 3H), 1.09 (t, J = 5.7 Hz, 3H). MS (ESI, 70 eV):
m/z = 214.3. Anal. Calcd for C9H14N2O2S (214.08) (%): C,
50.45; H, 6.59; N, 13.07; S, 14.96. Found (%): C, 50.10; H,
6.63; N, 13.44; S, 15.06.
(d, J = 3.5 Hz, 1H), 4.16–4.02 (m, 3H), 3.07 (s, 3H), 2.41
(s, 3H), 1.20 (t, J = 7.1 Hz, 3H), 1.07 (d, J = 6.3 Hz, 3H).
MS (ESI, 70 eV): m/z = 212.0. Anal. Calcd for
C10H16N2O3 (212.12) (%): C, 56.59; H, 7.60; N, 13.20.
Found (%): C, 56.78; H, 7.66; N, 13.12.
5.32 | Ethyl 1‐Ethyl‐4,6‐dimethyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4f')
5.27 | Ethyl 6‐Methyl‐2‐oxo‐4‐pentyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4a')[29]
White solid. 1H NMR (400 MHz, DMSO‐d6, δ, ppm):
10.11 (s, 1H), 9.28 (s, 1H), 4.17–4.00 (m, 3H), 2.20 (s,
3H), 1.29 (ddd, J = 27.9, 13.1, 6.9 Hz, 11H), 0.85 (t,
J = 6.6 Hz, 3H). MS (ESI, 70 eV): m/z = 270.1. Anal.
Calcd for C13H22N2O2S (270.14) (%): C, 57.75; H, 8.20;
White solid. IR (KBr, cm−1): 3228 (NH), 2985–2873 (C═H),
1
1681 (C═O), 1624 (C═C). H NMR (400 MHz, DMSO‐d6,
δ, ppm): 7.36 (d, J = 3.3 Hz, 1H), 4.17–4.01 (m, 3H), 3.76
(dt, J = 14.1, 7.1 Hz, 1H), 3.57 (dd, J = 14.4, 7.1 Hz, 1H),
2.41 (s, 3H), 1.20 (t, J = 7.1 Hz, 3H), 1.11–1.00 (m, 6H).
13C NMR (400 MHz, DMSO‐d6, δ, ppm): 166.03, 155.39,

ZHANG ET AL.
9
149.20, 104.85, 99.99, 59.83, 45.48, 37.17, 23.36, 15.74,
15.27, 14.65. MS (ESI, 70 eV): m/z = 226.1. Anal. Calcd
for C11H18N2O3 (226.13) (%): C, 58.39; H, 8.02; N, 12.38.
Found (%): C, 58.50; H, 7.92; N, 12.51.
5.38 | 3,4,7,8‐Tetrahydro‐4,7‐diphenylquinazoline‐2,5‐
(1H,6H)dione (4 l')[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.59
(d, J = 26.5 Hz, 1H), 7.83 (d, J = 21.3 Hz, 1H), 7.29 (ddd,
J = 25.1, 15.4, 6.5 Hz, 10H), 5.22 (d, J = 14.8 Hz, 1H),
3.56–3.14 (m, 1H), 2.94–2.53 (m, 3H), 2.38 (dd, J = 36.2,
13.9 Hz, 1H). MS (ESI, 70 eV): m/z = 318.1. Anal. Calcd
for C20H18N2O2 (318.14) (%): C, 75.45; H, 5.70; N, 8.80.
Found (%): C, 75.61; H, 5.55; N, 8.91.
5.33 | Methyl 6‐Methyl‐2‐oxo‐4‐phenyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 g')[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.24
(s, 1H), 7.78 (s, 1H), 7.37–7.20 (m, 5H), 5.15 (d,
J = 3.4 Hz, 1H), 3.53 (s, 3H), 2.26 (s, 3H). MS (ESI,
70 eV): m/z = 246.1. Anal. Calcd for C13H14N2O3 (246.1)
(%): C, 63.40; H, 5.73; N, 11.38. Found (%): C, 63.60; H,
5.85; N, 11.08.
5.39 | Methyl 4,6‐Dimethyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 m')[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.02
(d, J = 11.7 Hz, 1H), 7.23 (s, 1H), 4.12 (dd, J = 6.2,
3.4 Hz, 1H), 3.61 (s, 3H), 2.16 (s, 3H), 1.09 (d, J = 6.3 Hz,
3H). MS (ESI, 70 eV): m/z = 184.0. Anal. Calcd for
C8H12N2O3 (184.08) (%): C, 52.17; H, 6.57; N, 15.21. Found
(%): C, 52.33; H, 6.61; N, 15.49.
5.34 | Isopropyl 6‐Methyl‐2‐oxo‐4‐phenyl‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4 h')[5]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.18
(s, 1H), 7.73 (s, 1H), 7.28 (dt, J = 12.1, 7.7 Hz, 5H), 5.13
(d, J = 3.0 Hz, 1H), 4.81 (dt, J = 12.4, 6.2 Hz, 1H), 2.24
(s, 3H), 1.16 (d, J = 6.2 Hz, 3H), 0.98 (d, J = 6.2 Hz, 3H).
MS (ESI, 70 eV): m/z = 274.2. Anal. Calcd for
C15H18N2O3 (274.13) (%): C, 65.68; H, 6.61; N, 10.21.
Found (%): C, 65.83; H, 6.91; N, 10.00.
5.40 | Isopropyl 4,6‐Dimethyl‐2‐oxo‐1,2,3,4‐
tetrahydropyrimidine‐5‐carboxylate (4n')
White solid. IR (KBr, cm−1): 3248 (NH), 3134 (NH), 2979–
1
2941 (C─H), 1735(C═O), 1703 (C═O), 1624 (C═C). H
NMR (400 MHz, DMSO‐d6, δ, ppm): 8.97 (s, 1H), 7.21 (s,
1H), 4.91 (dd, J = 12.0, 5.9 Hz, 1H), 4.11 (s, 1H), 2.15 (s,
3H), 1.19 (d, J = 4.2 Hz, 6H), 1.09 (d, J = 5.8 Hz, 3H).
13C NMR (400 MHz, DMSO‐d6, δ, ppm): 165.31, 153.02,
148.02, 101.18, 66.55, 46.75, 23.87, 22.28, 22.17, 18.10.
MS (ESI, 70 eV): m/z = 212.0. Anal. Calcd for
C10H16N2O3 (212.12) (%): C, 56.59; H, 7.60; N, 13.20.
Found (%): C, 56.70; H, 7.83; N, 13.00.
5.35 | 5‐Acetyl‐3,4‐dihydro‐6‐methyl‐4‐
phenylpyrimidin‐2‐(1H)one(4i')[5]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.20
(s, 1H), 7.84 (s, 1H), 7.32 (d, J = 6.8 Hz, 2H), 7.26 (d,
J = 6.0 Hz, 3H), 5.27 (s, 1H), 2.30 (s, 3H), 2.11 (s, 3H).
MS (ESI, 70 eV): m/z = 230.1. Anal. Calcd for
C13H14N2O2 (230.11) (%): C, 67.81; H, 6.13; N, 12.17.
Found (%): C, 68.00; H, 5.97; N, 12.34.
ACKNOWLEDGMENT
The authors acknowledge the financial support of the
National Natural Science Foundation of China (no.
21402067).
5.36 | 5‐Benzoyl‐4,6‐diphenyl‐3,4‐dihydropyrimidin‐2‐
(1H)one (4j')[29]
1
White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.44
REFERENCES
(s, 1H), 8.01 (s, 1H), 7.51–6.94 (m, 15H), 5.34 (d,
J = 2.9 Hz, 1H). MS (ESI, 70 eV): m/z = 354.0. Anal. Calcd
for C23H18N2O2 (354.14) (%): C, 77.95; H, 5.12; N, 7.90.
Found (%): C, 77.85; H, 5.33; N, 7.73.
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White solid. H NMR (400 MHz, DMSO‐d6, δ, ppm): 9.47
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(s, 1H), 7.77 (s, 1H), 7.37–7.18 (m, 5H), 5.15 (d,
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How to cite this article: Zhang, X., Gu, X., Gao, Y.,
Nie, S., and Lu, H. (2016), (C5H6N4O)(C5H5N4O)3
(C5H4N4O)[Bi2Cl11]Cl2 as a simple and efficient cata-
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