Base-catalyzed, efficient synthesis of 5-substituted 3,6-dihydro-7H-1,2,3- triazolo[4,5-d]pyrimidin-7-ones

Article abstract of DOI:10.1055/s-2005-872077

The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with secondary amines or ROH to give 5-dialkylamino or 5-alkoxy 7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in the presence of a catalytic amou

Full text of DOI:10.1055/s-2005-872077

2544
PAPER
Base-Catalyzed, Efficient Synthesis of 5-Substituted 3,6-Dihydro-7H-1,2,3-
triazolo[4,5-d]pyrimidin-7-ones
S
ubstitute
u
d 3,6-Dihydr
n
o-7
H
-1,2,3-t
-
riazolo[4
F
,5-
d
]
pyrimidin
e
-
7-ones ng Zhao, Chang Xie, Ming-Wu Ding,* Hong-Wu He*
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University,
Wuhan, 430079, P. R. China
Fax +86(27)67862041; E-mail: mwding@mail.ccnu.edu.cn
Received 28 March 2005; revised 28 April 2005
pyrimidinones13,15 imply that guanidines 3 may be trans-
Abstract: The carbodiimides 2, obtained from aza-Wittig reactions
formed into 7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4
in the presence of a catalytic amount of sodium ethoxide.
of iminophosphorane 1 with aromatic isocyanates, reacted with sec-
ondary amines or ROH to give 5-dialkylamino or 5-alkoxy 7H-
However, when treated with sodium ethoxide in EtOH at
ic amount of EtONa in a mixed solvent (CH2Cl2–ROH). Reactions room temperature, the guanidines 3 were recovered un-
1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in the presence of a catalyt-
of 2 with phenols in presence of catalytic potassium carbonate in
changed, probably due to the low solubility of 3 in EtOH.
MeCN gave 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4
in satisfactory yields.
In refluxing EtOH in the presence of EtONa, a complex
mixture resulted, probably owning to the instability of the
Key words: pyrimidines, imides, cyclizations, aza-Wittig reac-
tions, heterocycles, guanines
product at reflux temperature in strong basic conditions.
We found that when a mixed solvent (CH2Cl2–EtOH) was
used in the presence of a catalytic amount of sodium
ethoxide, compounds 3 were converted easily to 5-di-
7H-1,2,3-Triazolo[4,5-d]pyrimidin-7-ones, which are
also named as 8-azaguanines, are of great importances be-
cause of their structural similarity with guanines. Some
derivatives of them have shown remarkable biological
(antiguanine) properties such as antitumor, antiviral, and
anti-HIV activities,1–5 whereas others exhibited good fun-
gicidal activities.6 The methods described for the prepara-
tion of this ring system either involves reaction of
properly substituted diaminopyrimidines with sodium ni-
trate and acetic acid, or reaction of aminotriazolecarbon-
amides with orthoformate, or cyclization of 5-acetamido-
4-ethoxycarbonyl- 1,2,3-triazoles with amine in the pres-
ence of phosphorus pentoxide.6–12 However, these meth-
ods often require relatively harsh acid, dehydrating
conditions or heating at high temperature, and there is no
report of a generally useful synthesis of 5-amino or 5-ar-
yl(alk)oxy substituted 7H-1,2,3-triazolo[4,5-d]pyrimidin-
7-ones starting from easily accessible 5-amino-4-ethoxy-
carbonyl-1,2,3-triazoles.
alkylamino-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones
4
(Y = NR1R2) in satisfactory yields at room temperature.
This may be due to the good solubility of 3 in the mixed
solvent. It is noteworthy that the isolated yield of 4 was
good even when Y is a bulky diisopropylamino group.
The results are listed in Table 1.
Recently we have been interested in the synthesis of
quinazolinones, thienopyrimidinones and imidazolinones
via aza-Wittig reaction of a or b ethoxycarbonyl imino-
phosphorane with aromatic isocyanate and subsequent re-
action with various nucleophiles under mild conditions.13–
Here we wish to report a base-catalyzed, efficient ap-
proach to 5-substituted 7H-1,2,3-triazolo[4,5-d]pyrimi-
din-7-ones.
Scheme 1
When carbodiimide 2 was reacted with ROH, only the
urea-type product 3 was obtained.18,19 However, 5-
alkoxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones
4
17
(Y = OR) were obtained from 3 in satisfactory yields in
the presence of catalytic amount of RONa by using the
mixed solvent (CH2Cl2–ROH). The reaction of carbodi-
imide 2 with phenols in the presence of a catalytic amount
of potassium carbonate produced 5-aryloxy-7H-1,2,3-tri-
azolo[4,5-d]pyrimidin-7-ones 4 (Y = OAr) directly in
good yields when MeCN was used as solvent. The reac-
tion is relatively insensitive to the presence or absence of
substituents on the phenols and the cyclization can be
completed smoothly at 40–50 °C. The facile cyclization
It was reported that iminophosphorane 1 reacted with ar-
omatic isocyanates to give carbodiimides 2, which were
allowed to react with secondary amines to provide
guanidines 3.18 Our recent results on synthesis of fused
SYNTHESIS 2005, No. 15, pp 2544–2548
x
x.
x
x
.
2
0
0
5
Advanced online publication: 22.07.2005
DOI: 10.1055/s-2005-872077; Art ID: F06005SS
© Georg Thieme Verlag Stuttgart · New York

PAPER
Substituted 3,6-Dihydro-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones
2545
5-Dialkylamino-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones (4)
To a solution of iminophosphorane 120,21 (2 mmol) in anhyd CH2Cl2
(15 mL) was added aromatic isocyanate (2 mmol) under nitrogen at
r.t. After the reaction mixture was allowed to stand for 24–30 hours
at 0–5 °C, the solvent was removed under reduced pressure and
Et2O–petroleum ether (1:2; 20 mL) was added to precipitate the
triphenylphosphine oxide. After filtration, the solvent was removed
to give carbodiimide 2, which was used directly without further pu-
rification. To the solution of 2 prepared above in CH2Cl2 (15 mL)
was added dialkylamine (2 mmol). After the reaction mixture was
allowed to stand for 0.5–6 h, the solution was condensed and anhyd
EtOH–CH2Cl2 (4:1, 10 mL) with several drops of EtONa in EtOH
was added. The mixture was stirred for 1–6 h at r.t. The solution was
concentrated under reduced pressure and the residue was recrystal-
lized from EtOH to give the 5-dialkylamino-7H-1,2,3-triazolo[4,5-
d]pyrimidin-7-ones 4.
Table 1 Preparation of 5-Substituted 7H-1,2,3-Triazolo[4,5-d]pyri-
midin-7-ones 4
Ar1
Ar2
Y
Yield
(%)a
4a
4b
4c
4d
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
NEt2
84
80
87
88
N(Pr)2
N(n-Bu)2
4e
4f
Ph
Ph
N(i-Bu)2
NMe(Ph)
N(i-Pr)2
NEt2
78
85
73
86
81
75
86
82
71
73
83
87
81
74
82
84
77
72
Ph
Ph
5-Diethylamino-3,6-dihydro-3,6-diphenyl-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4a)
White crystals; mp 182–183 °C.
4g
4h
4i
Ph
Ph
Ph
4-ClC6H4
IR (KBr): 1719 (C=O), 1520, 1354, 1080 cm–1.
4-ClC6H4
4-ClC6H4
Ph
Ph
NEt2
1H NMR (400 MHz, CDCl3): d = 0.88 (t, J = 7.2 Hz, 6 H), 3.20 (q,
J = 7.2 Hz, 4 H), 7.32–8.19 (m, 10 H).
4j
Ph
NMe(Ph)
OMe
13C NMR (100 MHz, CDCl3): d = 11.96 (2), 45.33 (2), 120.68 (2),
125.97, 127.75, 128.33, 128.80 (2), 129.12 (4), 136.18, 137.65,
147.74, 156.67, 158.28.
4k
4l
Ph
Ph
Ph
OEt
MS: m/z (%) = 360 (97) [M+], 332 (80), 303 (45), 200 (13), 77
(100).
4m
4n
4o
4p
4q
4r
4s
4t
Ph
Ph
OCH2C≡CH
OCH2CH=CH2
OEt
Ph
Ph
Anal. Calcd for C20H20N6O: C, 66.65; H, 5.59; N, 23.32. Found: C,
66.87; H, 5.41; N, 23.46.
Ph
4-ClC6H4
Ph
3,6-Dihydro-3,6-diphenyl-5-di(propyl)amino-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4b)
White crystals; mp 142–144 °C.
4-ClC6H4
Ph
OEt
Ph
4-MeOC6H4O
4-MeC6H4O
4-MeOC6H4O
4-MeC6H4O
PhO
IR (KBr): 1726 (C=O), 1521, 1370, 1038 cm–1.
Ph
Ph
1H NMR (400 MHz, CDCl3): d = 0.75 (t, J = 7.2 Hz, 6 H), 1.29–
1.35 (m, 4 H), 3.06 (t, J = 7.6 Hz, 4 H), 7.32–8.20 (m, 10 H).
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
3-MeC6H4
3-MeC6H4
3-MeC6H4
Ph
13C NMR (100 MHz, CDCl3): d = 11.15 (2), 20.39 (2), 53.23 (2),
120.63 (2), 125.86, 127.74, 128.42, 128.67 (2), 129.11 (4), 136.24,
137.50, 147.75, 156.64, 158.14.
4u
4v
MS: m/z (%) = 388 (73) [M+], 360 (25), 318 (17), 289 (100), 77
(68).
4-ClC6H4O
a Isolated yields based on iminophosphorane 1.
Anal. Calcd for C22H24N6O: C, 68.02; H, 6.23; N, 21.63. Found: C,
68.26; H, 6.20; N, 21.77.
condition (K2CO3 catalyzed) in this case is probably due
to the more acidic NHAr in intermediate 3 when Y is OAr.
5-Di(n-butyl)amino-3,6-dihydro-3,6-diphenyl-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4c)
White crystals; mp 138–140 °C.
In conclusion, we have developed an efficient synthesis of
5-substituted 7H-1,2,3-triazolo[4,5-d] pyrimidin-7-ones
via aza-Wittig reactions. Due to the mild reaction condi-
tions, good yields, easily accessible starting material and
straightforward product isolation, we think that the versa-
tile synthetic approach discussed here in many cases com-
pares favorably with other existing methods.
IR (KBr): 1725 (C=O), 1528, 1368, 1030 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85 (t, J = 7.2 Hz, 6 H), 1.12–
1.30 (m, 8 H), 3.10 (t, J = 7.6 Hz, 4 H), 7.31–8.21 (m, 10 H).
13C NMR (100 MHz, CDCl3): d = 13.62 (2), 20.06 (2), 29.14 (2),
51.40 (2), 120.69 (2), 125.90, 127.77, 128.36, 128.71, 129.09 (2),
129.14 (4), 136.26, 137.57, 147.78, 156.68, 158.22.
MS: m/z (%) = 416 (85) [M+], 388 (29), 331 (35), 289 (66), 77
(100).
Mps were uncorrected. MS spectra were measured on a Finnigan
Trace MS spectrometer. IR spectra were recorded on a PE-983 in-
frared spectrometer as KBr pellets with absorption in cm–1. NMR
spectra were recorded in CDCl3 on a Varian Mercury 400 spectrom-
eter and resonances are given in ppm (d) relative to TMS. Elemental
analyses were taken on a Vario EL III elemental analysis instru-
ment. Petroleum ether refers to the fraction with bp 60–90 °C.
Anal. Calcd for C24H28N6O: C, 69.21; H, 6.78; N, 20.18. Found: C,
69.16; H, 6.54; N, 20.24.
3,6-Dihydro-3,6-diphenyl-5-(1-piperidinyl)-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4d)
White crystals; mp 189–191 °C.
Synthesis 2005, No. 15, 2544–2548 © Thieme Stuttgart · New York

2546
J.-F. Zhao et al.
PAPER
IR (KBr): 1727 (C=O), 1518, 1348, 1252, 1026 cm–1.
13C NMR (100 MHz, CDCl3): d = 21.17 (2), 45.41 (2), 120.89 (2),
125.99, 127.98, 129.25 (2), 129.46 (2), 130.19 (2), 134.41, 136.11,
136.18, 147.75, 156.52, 158.15.
1H NMR (400 MHz, CDCl3): d = 1.29–1.47 (m, 6 H), 3.21 (q,
J = 5.6 Hz, 4 H), 7.35–8.19 (m, 10 H).
MS: m/z (%) = 396/394 (32/96) [M+], 366 (45), 337 (35), 136 (44),
76 (100).
13C NMR (100 MHz, CDCl3): d = 23.68, 24.50 (2), 49.97 (2),
120.69 (2), 126.32, 127.78, 128.13, 128.52 (2), 128.90 (2), 129.11
(2), 136.09, 137.37, 147.54, 156.36, 158.81.
Anal. Calcd for C20H19ClN6O: C, 60.84; H, 4.85; N, 21.28. Found:
C, 60.78; H, 4.81; N, 21.16.
MS: m/z (%) = 372 (76) [M+], 344 (55), 315 (16), 212 (32), 77
(100).
3-(4-Chlorophenyl)-5-diethylamino-3,6-dihydro-6-phenyl-7H-
1,2,3-triazolo[4,5-d]pyrimidin-7-one (4i)
White crystals; mp 234–235 °C.
Anal. Calcd for C21H20N6O: C, 67.73; H, 5.41; N, 22.57. Found: C,
67.58; H, 5.47; N, 22.75.
IR (KBr): 1716 (C=O), 1520, 1351, 1034 cm–1.
5-Di(isobutyl)amino-3,6-dihydro-3,6-diphenyl-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4e)
White crystals; mp 217–219 °C.
1H NMR (400 MHz, CDCl3): d = 0.88 (t, J = 7.2 Hz, 6 H), 3.21 (q,
J = 7.2 Hz, 4 H), 7.27–8.18 (m, 9 H).
IR (KBr): 1725 (C=O), 1523, 1367, 1033 cm–1.
13C NMR (100 MHz, CDCl3): d = 12.09 (2), 45.49 (2), 121.91 (2),
126.10, 128.57, 128.89 (2), 129.32 (2), 129.44 (2), 133.52, 134.91,
137.71, 147.89, 156.66, 158.52.
1H NMR (400 MHz, CDCl3): d = 0.82 (t, J = 6.8 Hz, 12 H), 1.88–
1.93 (m, 2 H), 2.92 (d, J = 6.8 Hz, 4 H), 7.33–8.21 (m, 10 H).
MS: m/z (%) = 396/394 (1/3) [M+], 366 (2), 287 (2), 137 (84), 77
(100).
13C NMR (100 MHz, CDCl3): d = 20.19 (4), 27.62 (2), 60.14 (2),
120.81, 125.75, 127.84, 128.44 (2), 128.65, 129.23 (4), 136.39,
137.30, 147.91, 156.65, 157.80.
Anal. Calcd for C20H19ClN6O: C, 60.84; H, 4.85; N, 21.28. Found:
C, 60.95; H, 4.74; N, 21.34.
MS: m/z (%) = 416 (67) [M+], 345 (30), 288 (100), 77 (74).
Anal. Calcd for C24H28N6O: C, 69.21; H, 6.78; N, 20.18. Found: C,
69.04; H, 6.84; N, 20.42.
3-(4-Chlorophenyl)-3,6-dihydro-6-phenyl-5-(N-phenyl-N-
methylamino)-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one (4j)
White crystals; mp 275–277 °C.
3,6-Dihydro-3,6-diphenyl-5-(N-phenyl-N-methylamino)-7H-
1,2,3-triazolo[4,5-d]pyrimidin-7-one (4f)
White crystals; mp 244–246 °C.
IR (KBr): 1722 (C=O), 1521, 1392, 1091 cm–1.
1H NMR (400 MHz, CDCl3): d = 3.37 (s, 3 H), 6.59–8.26 (m, 14 H).
IR (KBr): 1721 (C=O), 1532, 1387, 1066 cm–1.
13C NMR (100 MHz, CDCl3): d = 43.40, 122.15 (2), 125.70 (2),
126.30, 126.92, 127.76, 128.43 (2), 128.85 (2), 129.40 (2), 129.55
(2), 133.80, 134.83, 136.28, 145.68, 147.61, 156.26, 157.89.
1H NMR (400 MHz, CDCl3): d = 3.37 (s, 3 H), 6.58–8.28 (m, 15 H).
13C NMR (100 MHz, CDCl3): d = 43.31, 121.01 (2), 125.59 (2),
126.10, 126.85, 127.61, 128.08, 128.30 (2), 128.79 (2), 129.29 (4),
136.16, 136.27, 145.70, 147.53, 156.34, 157.66.
MS: m/z (%) = 430/428 (9/25) [M+], 400 (16), 365 (7), 234 (38), 77
(100).
Anal. Calcd for C23H17ClN6O: C, 64.41; H, 4.00; N, 19.60. Found:
C, 64.67; H, 4.18; N, 19.34.
MS: m/z (%) = 394 (98) [M+], 365 (100), 289 (64), 234 (88), 103
(97).
Anal. Calcd for C23H18N6O: C, 70.04; H, 4.60; N, 21.31. Found: C,
70.27; H, 4.71; N, 21.06.
5-Alkoxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones (4)
To 2 prepared above was added ROH (8 mL). After urea-type com-
pound 3 was precipitated from the reaction mixture, CH2Cl2 (2 mL)
was added to dissolve the solid and then RONa in ROH (several
drops) was added. The mixture was stirred for 6 h at r.t. The solution
was condensed and the precipitate was collected to give 5-alkoxy-
7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4.
3,6-Dihydro-3,6-diphenyl-5-di(isopropyl)amino-7H-1,2,3-tri-
azolo[4,5-d]pyrimidin-7-one (4g)
White crystals; mp 228–230 °C.
IR (KBr): 1721 (C=O), 1524, 1364, 1027 cm–1.
1H NMR (400 MHz, CDCl3): d = 1.10 (d, J = 6.8 Hz, 12 H), 3.62–
3.69 (m, 2 H), 7.29–8.12 (m, 10 H).
3,6-Dihydro-3,6-diphenyl-5-methoxy-7H-1,2,3-triazolo[4,5-
d]pyrimidin-7-one (4k)
White crystals; mp 203–204 °C.
13C NMR (100 MHz, CDCl3): d = 21.14 (4), 50.63 (2), 121.58 (2),
126.27, 128.02, 128.27, 129.08 (2), 129.17 (2), 129.28 (2), 136.06,
138.85, 147.70, 157.38, 157.60.
IR (KBr): 1721 (C=O), 1557, 1345, 1035 cm–1.
1H NMR (400 MHz, CDCl3): d = 4.03 (s, 3 H), 7.24–8.15 (m, 10 H).
MS: m/z (%) = 388 (29) [M+], 345 (15), 317 (64), 303 (28), 42
(100).
13C NMR (100 MHz, CDCl3): d = 56.89, 121.33 (2), 127.25, 128.15
(2), 128.48, 129.20, 129.40 (2), 129.45 (2), 134.08, 135.80, 146.89,
155.39, 157.41.
Anal. Calcd for C22H24N6O: C, 68.02; H, 6.23; N, 21.63. Found: C,
68.18; H, 6.01; N, 21.85.
MS: m/z (%) = 319 (100) [M+], 290 (21), 276 (36), 145 (83), 77
(88).
6-(4-Chlorophenyl)-5-diethylamino-3,6-dihydro-3-phenyl-7H-
1,2,3-triazolo[4,5-d]pyrimidin-7-one (4h)
White crystals; mp 231–232 °C.
Anal. Calcd for C17H13N5O2: C, 63.94; H, 4.10; N, 21.93. Found: C,
63.88; H, 4.04; N, 22.07.
IR (KBr): 1708 (C=O), 1541, 1353, 1090 cm–1.
3,6-Dihydro-3,6-diphenyl-5-ethoxy-7H-1,2,3-triazolo[4,5-d]py-
rimidin-7-one (4l)
White crystals; mp 217–219 °C.
1H NMR (400 MHz, CDCl3): d = 0.93 (t, J = 7.2 Hz, 6 H), 3.21 (q,
J = 7.2 Hz, 4 H), 7.28–8.17 (m, 9 H).
IR (KBr): 1725 (C=O), 1555, 1329, 1033 cm–1.
Synthesis 2005, No. 15, 2544–2548 © Thieme Stuttgart · New York

PAPER
Substituted 3,6-Dihydro-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones
2547
1H NMR (400 MHz, CDCl3): d = 1.29 (t, J = 7.2 Hz, 3 H), 4.51 (q,
J = 7.2 Hz, 2 H), 7.23–8.14 (m, 10 H).
13C NMR (100 MHz, CDCl3): d = 13.70, 66.49, 122.24 (2), 127.16,
128.02 (2), 129.01, 129.28 (2), 129.47 (2), 134.03 (2), 134.29,
146.95, 155.26, 156.96.
13C NMR (100 MHz, CDCl3): d = 13.78, 66.39, 121.31 (2), 127.24,
128.12 (2), 128.42, 129.06, 129.37 (4), 134.21, 135.84, 147.04,
155.50, 156.86.
MS: m/z (%) = 369/367 (25/72) [M+], 311 (44), 248 (38), 145 (100),
77 (92).
MS: m/z (%) = 333 (100) [M+], 276 (70), 248 (23), 145 (60), 77
(68).
Anal. Calcd for C18H14ClN5O2: C, 58.78; H, 3.84; N, 19.04. Found:
C, 58.62; H, 3.78; N, 19.16.
Anal. Calcd for C18H15N5O2: C, 64.86; H, 4.54; N, 21.01. Found: C,
64.63; H, 4.69; N, 21.07.
5-Aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones (4)
To the solution of 2 prepared above in MeCN (15 mL) was added
substituted phenol (2 mmol) and solid K2CO3 (0.04 g, 0.3 mmol).
The mixture was stirred for 6–10 h at 40–50 °C and filtered, the fil-
trate was condensed and the residue was recrystallized (CH2Cl2–pe-
troleum ether) to give 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyri-
midin-7-ones 4.
3,6-Dihydro-3,6-diphenyl-5-propargyloxy-7H-1,2,3-triazo-
lo[4,5-d]pyrimidin-7-one (4m)
White crystals; mp 226–227 °C.
IR (KBr): 3295, 2131 (C≡C), 1724 (C=O), 1557, 1372 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.55 (s, 1 H), 5.01 (s, 2 H), 7.25–
8.17 (m, 10 H).
3,6-Dihydro-3,6-diphenyl-5-(4-methoxyphenoxy)-7H-1,2,3-tri-
azolo[4,5-d]pyrimidin-7-one (4q)
White crystals; mp 235–236 °C.
13C NMR (100 MHz, CDCl3): d = 57.13, 76.25, 76.39, 121.41 (2),
127.47, 128.18 (2), 128.60, 129.38, 129.47 (2), 129.54 (2), 133.74,
135.75, 146.45, 155.25, 155.93.
IR (KBr): 1752 (C=O), 1559, 1346, 1243 cm–1.
1H NMR (400 MHz, CDCl3): d = 3.83 (s, 3 H), 6.89–7.98 (m, 14 H).
MS: m/z (%) = 343 (50) [M+], 276 (41), 145 (100), 129 (30), 77
(67).
13C NMR (100 MHz, CDCl3): d = 55.66, 114.34 (2), 122.15 (2),
127.58 (2), 128.14, 128.26 (2), 129.26 (2), 129.43 (2), 129.66 (2),
134.16, 135.81, 144.94, 146.53, 155.35, 156.92, 157.73.
Anal. Calcd for C19H13N5O2: C, 66.47; H, 3.82; N, 20.40. Found: C,
66.53; H, 3.76; N, 20.27.
MS: m/z (%) = 411 (2) [M+], 383 (1), 204 (3), 128 (12), 76 (100).
5-Allyloxy-3,6-dihydro-3,6-diphenyl-7H-1,2,3-triazolo[4,5-
d]pyrimidin-7-one (4n)
White crystals; mp 203–205 °C.
Anal. Calcd for C23H17N5O3: C, 67.15; H, 4.16; N, 17.02. Found: C,
67.34; H, 4.07; N, 17.15.
IR (KBr): 1718 (C=O), 1553, 1367, 769 cm–1.
3,6-Dihydro-3,6-diphenyl-5-(4-methylphenoxy)-7H-1,2,3-tri-
azolo[4,5-d]pyrimidin-7-one (4r)
White crystals; mp 209–211 °C.
1H NMR (400 MHz, CDCl3): d = 4.93 (d, J = 5.2 Hz, 2 H), 5.13–
5.23 (m, 2 H), 5.83–5.93 (m, 1 H), 7.24–8.12 (m, 10 H).
IR (KBr): 1737 (C=O), 1549, 1348, 1249 cm–1.
13C NMR (100 MHz, CDCl3): d = 70.18, 118.91, 121.44 (2),
127.34, 128.15 (2), 128.53, 129.22, 129.42 (2), 129.47 (2), 130.44,
134.11, 135.80, 146.90, 155.45, 156.56.
1H NMR (400 MHz, CDCl3): d = 2.38 (s, 3 H), 7.02–7.96 (m, 14 H).
13C NMR (100 MHz, CDCl3): d = 20.84, 120.67 (2), 120.91 (2),
128.14, 128.24 (2), 128.39, 129.24 (2), 129.41, 129.65 (2), 129.87
(2), 134.16, 135.81, 136.26, 146.52, 149.28, 155.35, 156.72.
MS: m/z (%) = 345 (41) [M+], 316 (15), 276 (39), 145 (100), 77
(77).
MS: m/z (%) = 395 (2) [M+], 367 (2), 204 (8), 128 (14), 76 (100).
Anal. Calcd for C19H15N5O2: C, 66.08; H, 4.38; N, 20.28. Found: C,
66.23; H, 4.15; N, 20.17.
Anal. Calcd for C23H17N5O2: C, 69.86; H, 4.33; N, 17.71. Found: C,
69.61; H, 4.16; N, 17.84.
6-(4-Chlorophenyl)-3,6-dihydro-5-ethoxy-3-phenyl-7H-1,2,3-
triazolo[4,5-d]pyrimidin-7-one (4o)
White crystals; mp 245–246 °C.
3-(4-Chlorophenyl)-3,6-dihydro-5-(4-methoxyphenoxy)-6-(3-
methylphenyl)-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one (4s)
White crystals; mp 200–201 °C.
IR (KBr): 1719 (C=O), 1558, 1325, 1091 cm–1.
1H NMR (400 MHz, CDCl3): d = 1.31 (t, J = 7.2 Hz, 3 H), 4.52 (q,
J = 7.2 Hz, 2 H), 7.18–8.12 (m, 9 H).
IR (KBr): 1734 (C=O), 1560, 1505, 1350 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.45 (s, 3 H), 3.84 (s, 3 H), 6.91–
7.95 (m, 12 H).
13C NMR (100 MHz, CDCl3): d = 13.84, 66.63, 121.40 (2), 127.11,
128.54, 129.43 (2), 129.60 (2), 129.69 (2), 132.68, 135.15, 135.79,
147.02, 155.34, 156.60.
13C NMR (100 MHz, CDCl3): d = 21.32, 55.67, 114.33 (2), 121.64
(2), 122.16 (2), 124.99, 127.54, 128.56, 129.38 (4), 130.31, 133.90,
134.31, 139.76, 144.88, 146.49, 155.22, 157.20, 157.76.
MS: m/z (%) = 369/367 (32/92) [M+], 310 (29), 282 (16), 124 (30),
76 (100).
MS: m/z (%) = 461/459 (17/52) [M+], 430 (23), 396 (15), 314 (100),
152 (66).
Anal. Calcd for C18H14ClN5O2: C, 58.78; H, 3.84; N, 19.04. Found:
C, 58.83; H, 3.75; N, 19.02.
Anal. Calcd for C24H18ClN5O3: C, 62.68; H, 3.95; N, 15.23. Found:
C, 62.72; H, 3.91; N, 15.35.
3-(4-Chlorophenyl)-3,6-dihydro-5-ethoxy-6-phenyl-7H-1,2,3-
triazolo[4,5-d]pyrimidin-7-one (4p)
White crystals; mp 199–200 °C.
3-(4-Chlorophenyl)-3,6-dihydro-5-(4-methylphenoxy)-6-(3-
methylphenyl)-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one (4t)
White crystals; mp 210–211 °C.
IR (KBr): 1731 (C=O), 1550, 1332, 1073 cm–1.
1H NMR (400 MHz, CDCl3): d = 1.29 (t, J = 7.2 Hz, 3 H), 4.51 (q,
J = 7.2 Hz, 2 H), 7.22–8.12 (m, 9 H).
IR (KBr): 1753 (C=O), 1550, 1507, 1352 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.40 (s, 3 H), 3.45 (s, 3 H), 7.01–
7.95 (m, 12 H).
Synthesis 2005, No. 15, 2544–2548 © Thieme Stuttgart · New York

2548
J.-F. Zhao et al.
PAPER
13C NMR (100 MHz, CDCl3): d = 20.88, 21.34, 120.96 (2), 121.65
(2), 125.01, 127.60, 128.58, 129.40 (2), 129.45 (2), 129.90 (2),
130.34, 133.91, 134.37, 136.38, 139.78, 146.51, 149.26, 155.26,
157.04.
References
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1314.
MS: m/z (%) = 443 (5) [M+], 415 (2), 338 (2), 110 (18), 89 (100).
Anal. Calcd for C24H18ClN5O2: C, 64.94; H, 4.09; N, 15.78. Found:
C, 64.87; H, 4.15; N, 15.79.
(3) Nieto, M. I.; Caamano, O.; Fernandez, F.; Gomez, M.;
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3-(4-Chlorophenyl)-3,6-dihydro-6-(3-methylphenyl)-5-phen-
oxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one (4u)
White crystals; mp 228–230 °C.
IR (KBr): 1754 (C=O), 1551, 1511, 1355 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.46 (s, 3 H), 7.13–7.93 (m, 13 H).
13C NMR (100 MHz, CDCl3): d = 21.33, 121.39 (2), 121.58 (2),
125.00, 126.65, 127.57, 128.57, 129.34 (2), 129.49 (4), 130.36,
133.90, 134.28, 139.80, 146.40, 151.42, 155.20, 156.97.
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Rodriquez, A. M.; Rodriquez, M. C.; Sanchez, R. A.
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MS: m/z (%) = 431/429 (2/6) [M+], 401 (1), 323 (3), 110 (26), 76
(100).
Anal. Calcd for C23H16ClN5O2: C, 64.27; H, 3.75; N, 16.29. Found:
C, 64.03; H, 3.58; N, 16.37.
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5-(4-Chlorophenoxy)-3-(4-chlorophenyl)-3,6-dihydro-6-phen-
yl-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one (4v)
White crystals; mp 248–249 °C.
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1996, 33, 1605.
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IR (KBr): 1741 (C=O), 1559, 1350, 1082 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.10–7.59 (m, 11 H), 7.88 (d,
J = 9.2 Hz, 2 H).
13C NMR (100 MHz, CDCl3): d = 121.76 (2), 122.81 (2), 127.65,
128.06 (2), 129.51 (3), 129.58 (2), 129.76 (2), 132.16, 133.83,
134.21 (2), 146.24, 149.76, 154.99, 156.54.
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MS: m/z (%) = 451/449 (4/6) [M+], 421 (5), 386 (7), 136 (36), 110
(100).
Anal. Calcd for C22H13Cl2N5O2: C, 58.68; H, 2.91; N, 15.55. Found:
C, 58.55; H, 2.96; N, 15.49.
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Acknowledgment
We gratefully acknowledge financial support of this work by the
National Key Project for Basic Research (2003CB114400,
2003CB114406) and the National Natural Science Foundation of
China (Project No. 20372023, 20102001).
Synthesis 2005, No. 15, 2544–2548 © Thieme Stuttgart · New York