Synthesis and cytotoxicity studies of novel [1,2,4] Triazolo [1,5-a]pyrimidine-7-amines

Article abstract of DOI:10.1248/cpb.56.941

A series of novel N-anilino-5-methyl-2-(3-(5-(alkylaminomethyl)furan-2-yl- methylthio)propyl)-[1,2,4]triazolo-[1,5-a]pyrimidine-7-amine derivatives were synthesized and evaluated for their in vitro cytotoxicity against two cancer cell lines, Bel-7402 and HT-1080. Compounds 9, 14, 19 and 23 possessed marked cytotoxicity, especially 23 (with IC₅₀ values of 15.0μM and 7.8μM against Bel-7402 and HT-1080 cell lines, respectively), which had emerged as lead compound. The activity was found to depend strongly on substitution pattern of the side chains at C-2 position, and 4-triflouromethylanilino substituent at C-7 position was an option for anticancer potency.

Full text of DOI:10.1248/cpb.56.941

July 2008
Chem. Pharm. Bull. 56(7) 941—945 (2008)
941
Synthesis and Cytotoxicity Studies of Novel
[1,2,4]Triazolo[1,5-a]pyrimidine-7-amines
Xin ZHAI, Yan-Fang ZHAO, Ya-Jing LIU, Yong ZHANG, Feng-Qiang XUN, Jun LIU, and Ping GONG*
Key Lab of New Drugs Design and Discovery of Liaoning Province, School of Pharmaceutical Engineering, Shenyang
Pharmaceutical University; 110016, Shenyang, P. R. China.
Received February 25, 2008; accepted April 3, 2008; published online April 7, 2008
A series of novel N-anilino-5-methyl-2-(3-(5-(alkylaminomethyl)furan-2-yl-methylthio)propyl)-[1,2,4]tria-
zolo-[1,5-a]pyrimidine-7-amine derivatives were synthesized and evaluated for their in vitro cytotoxicity against
two cancer cell lines, Bel-7402 and HT-1080. Compounds 9, 14, 19 and 23 possessed marked cytotoxicity, espe-
cially 23 (with IC50 values of 15.0 mM and 7.8 mM against Bel-7402 and HT-1080 cell lines, respectively), which had
emerged as lead compound. The activity was found to depend strongly on substitution pattern of the side chains
at C-2 position, and 4-triflouromethylanilino substituent at C-7 position was an option for anticancer potency.
Key words [1,2,4]triazolo[1,5-a]pyrimidine-7-amine; synthesis; cytotoxicity
Cancer is a disease of striking significance in the world structure of 7—24 in Fig. 1.
today. It represents the second leading cause of human mor-
tality after cardiovascular diseases. In order to develop more Results and Discussion
effective and reliable anticancer agents, a large number of
Chemistry The title [1,2,4]triazolo[1,5-a]pyrimidine-7-
compounds bearing nitrogen-containing fused heterocyclic amine derivatives 7—24 were synthesized as shown in Chart
skeletons, such as 4-anilinoquinazolines, pyrazolopyrim- 1. Commercially available g-butyrolactone was treated with
idines, triazolopyrimidines, pyrrolopyrimidines, pyrazolopy- aminoguanidine carbonate in pyridine to give the 5-amino-3-
ridazines and imidazopyrazines, have been discovered partic- (3-hydroxypropyl)-4H-[1,2,4]-triazole 2 in 40% yield exclu-
ularly and many of them exhibited excellent anticancer activ- sively. As described in literature,11) cyclization of 2 with
ity.1—5)
ethyl acetoacetate was carried out in acetic acid at reflux to
Recently, [1,2,4]triazolo[1,5-a]pyrimidines have aroused afford the 3ꢀ-hydroxy acetylized intermediate, which was
increasing attentions from chemical and biological view converted to hydroxylate 3 by further reaction with ammonia
points since they were proved to be the promising anticancer in methanol in 88% yield. Subsequent treatment of 3 with
agents with a unique mechanism of promoting tubulin poly- excess phosphorus oxychloride afforded chloro derivative 4,
merization1,6) as well as the mechanism of cyclin-dependent a key synthon for further elaboration, in 94% yield. Coupling
kinases-2 inhibition.7) It was not until recently that some reaction of 4 with various anilines provided the intermediates
N-anilino-[1,2,4]triazolo[1,5-a]pyrimidine-7-amine analogs 5a—d in 87—93% yields after recrystallization. By etherifi-
bearing functional groups at C-2 position were reported for cation of 5a—d with (furan-2-yl)methanethiol in the pres-
their good cytotoxicity,8,9) which have largely inspired us and ence of an excess amount of sodium hydride in dried DMF,
directed parallel developments in the chemistry and cytotoxi- the key intermediates 6a—d were obtained.
city studies of these related derivatives.10) With an aim to
To further investigate the influence on cytotoxicity of polar
produce [1,2,4]triazolo[1,5-a]pyrimidine-7-amine derivatives chains that facilitate the solubility and the biological interac-
endowed with improved solubility and better biological inter- tions, we introduced various Mannich bases into the C-5 po-
actions, a series of new molecules containing nitrogen atoms sition of furan ring in the side chain by reaction of com-
in the terminal of side chain at C-2 position on the scaffold pounds 6a—d with appropriate secondary amines and
were designed and synthesized. Further modifications were formaldehyde, followed by column chromatographic purifi-
performed by introducing various alkylaminomethyl func- cation to afford the desired compounds 7—24 in 45—80%
tional groups into C-5 position of furan ring in the side chain yields.
and substituted anilines into C-7 position in the [1,2,4]tria-
zolo[1,5-a]pyrimidine core.
Cytotoxicity and Discussion Cytotoxicity of the synthe-
sized compounds 7—24 against Bel-7402 (Human Liver
In this paper, we would like to report the synthesis and cy- Cancer) and HT-1080 (Human Fibro Sarcoma) cell lines
totoxicity of a series of novel N-anilino-5-methyl-2-(3-(5- were determined by MTT assay. Cisplatin as positive control,
(alkylaminomethyl)furan-2-yl-methylthio)propyl)-[1,2,4]tria- and the results expressed as IC50 are summarized in Table 1.
zolo[1,5-a]pyrimidine-7-amines represented by the general
As shown in Table 1, most of the evaluated compounds ex-
hibited good cytotoxicity, and compounds 9, 14, 19 and 23,
bearing pyrrolidinylmethyl groups at C-5 position on furyl
moieties, possessed even better in vitro cytotoxicity against
both two tumor cell lines than cisplatin. Among all the tested
compounds, 23 was of particular interest because of its
marked activity (IC50 values of 15.0 mM and 7.8 mM against
Bel-7402 and HT-1080 cell lines, respectively) and had
emerged as lead compound.
Fig. 1. Structure of 7—24
∗ To whom correspondence should be addressed. e-mail: gongpinggp@126.com
© 2008 Pharmaceutical Society of Japan

942
Vol. 56, No. 7
Reagents and conditions: (a) aminoguanidine, pyridine, reflux, 10 h; (b) i) ethyl acetoacetate, acetic acid, reflux, 30 h; ii) methanol, ammonia, r.t., 24 h; (c) POCl3, reflux, 3 h; (d)
R1-substituted aniline, i-PrOH, 50 °C, 3 h; (e) (furan-2-yl)methanethiol, NaH, DMF, 50 °C, 0.5 h; (f) HCHO, R2R3NH, AcOH, 50 °C, 4 h.
Chart 1. Synthesis of Target Compounds 7—24
Table 1. The Substituents and Cytotoxicity of Compounds 7—24
IC50 (mM)
ment in anti-tumor potency. A case in point is that compound
17 with morpholinylmethyl group at C-5 position of furan
ring almost abolished the activity, whereas 19 bearing pyrro-
lidinylmethyl substituent provided a 2-fold increase in po-
tency against two tumor cell lines relative to the positive con-
trol. On the other hands, 4-triflouromethylanilino substituent
at C-7 position on the skeleton was an option for anticancer
potency, as 21—24 showed more potent cytotoxicity superior
to the corresponding compounds bearing 3-chloroanilino, 3-
chloro-4-fluoroanilino and 4-trifluoromethoxyanilino sub-
stituents at C-7 position. Furthermore, all of the compounds,
except for 12 and 21, were more potent on the HT-1080 cells
than on the Bel-7402 cells (about 2-fold in the case of 9, 10,
14, 16, 19, 20, 23).
Compd.
R1
NR2R3
Bel-7402
HT-1080
7
8
3-Cl
56.0
28.3
29.0
71.2
30.3
56.7
27.3
33.5
34.7
48.6
23.1
13.1
29.8
25.6
71.2
27.0
18.3
25.8
3-Cl
9
3-Cl
10
11
12
13
14
15
3-Cl
3-Cl
3-Cl, 4-F
3-Cl, 4-F
3-Cl, 4-F
3-Cl, 4-F
Conclusion
We reported the synthesis and evaluation of cytotoxic ac-
tivity of novel [1,2,4]triazolo[1,5-a]pyrimidine-7-amine de-
rivatives. Among the tested compounds, 23 is considered
promising lead for further structural modifications. The ac-
tivity was found to depend strongly on substitution pattern of
the side chains at C-2 position, so eventually the activity of
the compounds could be tailored by further structural modifi-
cations. The results of this study will provide useful informa-
tion for the design of novel molecules as cytotoxic agents.
16
17
3-Cl, 4-F
4-OCF3
43.6
20.9
ꢃ300
182.9
18
19
20
21
22
23
24
4-OCF3
4-OCF3
4-OCF3
4-CF3
35.6
19.3
42.6
40.0
22.3
15.0
20.1
9.0
Experimental
29.2
104.1
12.0
7.8
Melting points were determined by the capillary tube method and were
uncorrected. Infrared spectra were obtained from KBr pellets on a Bruker
IFS 55 instrument. 1H-NMR spectra were recorded at 300 MHz on a Bruker
ARX-300 instrument and chemical shifts are reported in parts per million
(d) downfield from TMS as the internal standard. Mass spectra were car-
rided out with an Agilent 1100 HPLC-MS instrument. Elemental analyses
were performed with a Carlo-Erba 1106 analyzer. All reagents and solvents
were commercially available unless otherwise indicated.
5-Amino-3-(3-hydroxypropyl)-4H-[1,2,4]triazole (2) A mixture of
aminoguanidine (65 g, 0.55 mol) and g-butyrolactone (43 g, 0.50 mol) in
pyridine (900 ml) was stirred for 10 h at reflux. The solvent was evaporated
under vacuum and the resultant mixture was filtered to give a pale solid. The
mass product was recrystallized from absolute ethanol (150 ml) and dried to
give 28 g (40%) of 2 as a white solid, mp 147—148 °C (lit. 149—150 °C12)).
1H-NMR (DMSO-d6) d: 1.71 (2H, m, C2ꢀ-CH2), 2.44 (2H, t, Jꢁ6.0 Hz, C1ꢀ-
CH2), 3.41 (2H, t, Jꢁ6.2 Hz, C3ꢀ-CH2), 4.45 (1H, s, OH), 5.55 (2H, br s,
NH2), 11.51 (1H, br s, NH). MS m/z: 142.1 (Mꢂ); Anal. Calcd for
C5H10N4O: C, 42.24; H, 7.09; N, 39.41; Found: C, 42.01; H, 7.01; N, 39.23.
7-Hydroxyl-2-(3-hydroxypropyl)-5-methyl-[1,2,4]triazolo[1,5-a]pyrim-
idine (3) A mixture of 2 (28 g, 0.20 mol) and ethyl acetoacetate (30.8 g,
0.24 mol) in acetic acid (300 ml) was stirred for 30 h at reflux. Acetic acid
was evaporated under vacuum and the resultant mixture was filtered. The re-
sulting off-white solid was then added into the saturated ammonia methanol
(300 ml) and stirred at room temperature for 24 h. The mixture was evapo-
rated and water (400 ml) was added, which was then acidified with dilute hy-
4-CF3
4-CF3
4-CF3
35.7
35
30.1
22
Cisplatin
The data indicated that 3-(5-(alkylaminomethyl)ffuran-2-
yl-methylthio)propyl side chain at C-2 position on [1,2,4]tri-
azolo[1,5-a]pyrimidine scaffold had a very important effect
on anti-tumor activity, and variations of the terminal sub-
stituents at C-5 position of furan ring would change the activ-
ity dramatically. Generally, pyrrolidinyl was the most potent
substituent which produced the compounds with excellent
activity, as demonstrated by 9, 14, 19 and 23. In addition,
piperidinyl and dimethylamino also had good contributions
to the anti-tumor activity, while morpholinyl and 4-
methylpiperizinyl resulted in dramatic decrease or abolish-

July 2008
943
drochloride solution to pH 5—6. The resulting precipitate was filtered and
methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (6b) Prepared from 5b,
recrystallized from ethanol to give the product 3 (37 g, 88%), mp 204— 82% yield. mp 155—157 °C. 1H-NMR (DMSO-d6) d: 1.99 (2H, m, C2ꢀ-
1
206 °C. H-NMR (DMSO-d6) d: 1.85 (2H, m, C2ꢀ-CH2), 2.30 (3H, s, CH3),
CH2), 2.42 (3H, s, CH3), 2.61 (2H, t, Jꢁ7.0 Hz, C1ꢀ-CH2), 2.88 (2H, t,
2.72 (2H, t, Jꢁ6.0 Hz, C1ꢀ-CH2), 3.45 (2H, t, Jꢁ6.1 Hz, C3ꢀ-CH2), 4.49 (1H, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.77 (2H, s, C5ꢀ-CH2), 4.12 (1H, br s, NH), 6.02 (1H, d,
br s, OH), 5.76 (1H, s, C6-H), 12.98 (1H, br s, C7-OH). MS m/z: 208.1 (Mꢂ);
Jꢁ3.8 Hz, C3ꢅ-H), 6.14 (1H, t, C4ꢅ-H), 6.32 (1H, s, C6-H), 7.08 (1H, d,
Anal. Calcd for C9H12N4O2: C, 51.92; H, 5.81; N, 26.91; Found: C, 51.86; H, Jꢁ2.0 Hz, C5ꢅ-H), 7.41—7.50 (2H, m, Ph-C2,6-2H), 7.64 (1H, m, Ph-C5-H).
5.68; N, 26.79.
MS m/z: 431.9 (Mꢂ); Anal. Calcd for C20H19ClFN5OS: C, 55.62; H, 4.43; N,
7-Chloro-2-(3-chloropropyl)-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine 16.21; Found: C, 55.58; H, 4.38; N, 16.19.
(4) A mixture of 3 (37 g, 0.18 mol) and phosphorus oxychloride (265 g,
N-(4-(Trifluoromethoxy)phenyl)-2-(3-(ffuran-2-yl-methylthio)propyl)-
1.70 mol) was heated to reflux for 3 h, and then was concentrated in vacuum 5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (6c) Prepared from
1
to result a red oil, which was poured into water, and extracted with chloro- 5c, 85% yield. mp 145—147 °C. H-NMR (DMSO-d6) d: 1.99 (2H, m, C2ꢀ-
form (250 mlꢄ3). The organic layer was then washed with water three CH2), 2.42 (3H, s, CH3), 2.62 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.90 (2H, t,
times, dried with anhydrous magnesium sulfate and concentrated to give 4 Jꢁ7.1 Hz, C3ꢀ-CH2), 3.73 (2H, s, C5ꢀ-CH2), 4.31 (1H, br s, NH), 6.07 (1H, d,
(41 g, 94%) as a yellow solid (LC purity: 96%, MS m/z: 245.2 (Mꢂ)), which Jꢁ3.7 Hz, C3ꢅ-H), 6.15 (1H, t, C4ꢅ-H), 6.41 (1H, s, C6-H), 7.13 (1H, d,
was directly used in next step without purification.
Jꢁ2.0 Hz, C5ꢅ-H), 7.43 (2H, d, Jꢁ8.7 Hz, Ph-C2,6-2H), 7.55 (2H, d,
General Procedure for the Preparation of the N-Anilino-2-(3-chloro- Jꢁ8.7 Hz, Ph-C3,5-2H). MS m/z: 463.6 (Mꢂ); Anal. Calcd for
propyl)-5-methyl-[1,2,4]triazolo-[1,5-a]pyrimidin-7-amines
A mixture C21H20F3N5O2S: C, 54.42; H, 4.35; N, 15.11; Found: C, 54.25; H, 4.28; N,
of R1-substituted anilines (44 mmol) and 4 (10 g, 40 mmol) in isopropanol
15.04.
N-(4-(Trifluoromethyl)phenyl)-2-(3-(ffuran-2-yl-methylthio)propyl)-5-
(100 ml) was stirred for 3 h at 50 °C. After cooling to room temperature, the
formed precipitates was filtered, washed with water, dried and crystallized methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (6d) Prepared from 5d,
from methanol to give 5a—d (87—93%) as pale powder.
81% yield. mp 157—159 °C. 1H-NMR (DMSO-d6) d: 2.01 (2H, m, C2ꢀ-
N-(3-Chlorophenyl)-2-(3-chloropropyl)-5-methyl-[1,2,4]triazolo[1,5- CH2), 2.44 (3H, s, CH3), 2.61 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.91 (2H, t,
a]pyrimidin-7-amine (5a) Prepared from 4 and 3-chlorophenyl amine, Jꢁ7.1 Hz, C3ꢀ-CH2), 3.77 (2H, s, C5ꢀ-CH2), 4.37 (1H, br s, NH), 6.02 (1H, d,
87% yield. mp 168—169 °C. 1H-NMR (DMSO-d6) d: 1.92 (2H, m, C2ꢀ- Jꢁ3.7 Hz, C3ꢅ-H), 6.14 (1H, t, C4ꢅ-H), 6.47 (1H, s, C6-H), 7.21 (1H, d,
CH2), 2.38 (3H, s, CH3), 2.67 (2H, t, Jꢁ6.1 Hz, C1ꢀ-CH2), 3.22 (2H, t, Jꢁ2.1 Hz, C5ꢅ-H), 7.64 (2H, d, Jꢁ8.7 Hz, Ph-C2,6-2H), 7.80 (2H, d,
Jꢁ6.1 Hz, C3ꢀ-CH2), 4.19 (1H, br s, NH), 6.34 (1H, s, C6-H), 7.24 (1H, m,
Jꢁ8.7 Hz, Ph-C3,5-2H). MS m/z: 447.8 (Mꢂ); Anal. Calcd for
Ph-C2-H), 7.37—7.42 (3H, m, Ph-C4,5,6-3H). MS m/z: 336.2 (Mꢂ); Anal. C21H20F3N5OS: C, 56.37; H, 4.50; N, 15.65; Found: C, 56.32; H, 4.48; N,
Calcd for C15H15Cl2N5: C, 53.58; H, 4.50; N, 20.83; Found: C, 53.52; H, 15.60.
4.47; N, 20.77.
General Procedure for the Preparation of N-Anilino-5-methyl-2-(3-
((5-(alkyl aminomethyl)furan-2-yl)methylthio)propyl)-[1,2,4]triazolo-
[1,5-a]pyrimidine-7-amines Formaldehyde (0.6 g, 8 mmol) was added
N-(3-Chloro-4-fluorophenyl)-2-(3-chloropropyl)-5-methyl-[1,2,4]tria-
zolo[1,5-a]pyrimidin-7-amine (5b) Prepared from 4 and 3-chloro-4-fluo-
rophenyl amine, 89% yield. mp 175—176 °C. H-NMR (DMSO-d6) d: 1.94 into acetic acid (20 ml) containing an appropriate amine (R2R3NH,
1
(2H, m, C2ꢀ-CH2), 2.38 (3H, s, CH3), 2.67 (2H, t, Jꢁ6.0 Hz, C1ꢀ-CH2), 3.23 13 mmol). The mixture was stirred at 30 °C for 10 min, and then 6a—d
(2H, t, Jꢁ6.2 Hz, C3ꢀ-CH2), 4.23 (1H, br s, NH), 6.36 (1H, s, C6-H), 7.43—
7.51 (2H, m, Ph-C2,6-2H), 7.66 (1H, m, Ph-C5-H). MS m/z: 354.1 (Mꢂ);
(5 mmol) was added. After stirring at 50 °C for 4 h, the mixture was concen-
trated in vacuum. The residue was treated with water (50 ml), basified with
Anal. Calcd for C15H14Cl2FN5: C, 50.86; H, 3.98; N, 19.77; Found: C, 50.82; concentrated aqueous sodium hydroxide to pH 9—10, extracted with meth-
H, 3.90; N, 19.69.
ylene dichloride, and then dried over magnesium sulfate. Evaporation of the
solvent provided an oil residue, which was purified by column chromatogra-
N-(4-(Trifluoromethoxy)phenyl)-2-(3-chloropropyl)-5-methyl-[1,2,4]-
triazolo[1,5-a]pyrimidin-7-amine (5c) Prepared from 4 and 4-(trifluoro- phy to give the final products 7—24 as off-white powder.
methoxy) phenyl amine, 93% yield. mp 154—155 °C. 1H-NMR (DMSO-d6)
N-(3-Chlorophenyl)-5-methyl-2-(3-((5-(morpholinomethyl)furan-2-
d: 1.94 (2H, m, C2ꢀ-CH2), 2.38 (3H, s, CH3), 2.67 (2H, t, Jꢁ6.1 Hz, C1ꢀ- yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (7) Pre-
CH2) , 3.23 (2H, t, Jꢁ6.2 Hz, C3ꢀ-CH2), 4.16 (1H, br s, NH), 6.36 (1H, s, C6- pared from 6a and morpholine, 73% yield. mp 170—172 °C. 1H-NMR
H), 7.35 (2H, d, Jꢁ8.7 Hz, Ph-C2,6-2H), 7.52 (2H, d, Jꢁ8.7 Hz, Ph-C3,5-2H). (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-CH2), 2.42 (3H, s, CH3), 2.60 (2H, t,
MS m/z: 385.9 (Mꢂ); Anal. Calcd for C16H15ClF3N5O: C, 49.81; H, 3.92; N, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.67 (4H, br s, morpholino-C2,6-2CH2), 2.89 (2H, t,
18.15; Found: C, 49.78; H, 3.85; N, 18.10.
Jꢁ7.1 Hz, C3ꢀ-CH2), 3.64 (4H, br s, morpholino-C3,5-2CH2), 3.78 (2H, s,
N-(4-(Trifluoromethyl)phenyl)-2-(3-chloropropyl)-5-methyl-[1,2,4]tri- C5ꢀ-CH2), 3.85 (2H, s, NCH2), 6.25 (1H, d, Jꢁ2.8 Hz, C3ꢅ-H), 6.32 (1H, d,
azolo[1,5-a]pyrimidin-7-amine (5d) Prepared from 4 and 4-(trifluoro- Jꢁ2.8 Hz, C4ꢅ-H), 6.44 (1H, s, C6-H), 7.34 (1H, m, Ph-C2-H), 7.46—7.52
methyl) phenyl amine, 91% yield. mp 147—148 °C. 1H-NMR (DMSO-d6) (3H, m, Ph-C4,5,6-3H). IR (KBr) cmꢆ1: 3445.2, 2968.3, 1608.4, 1566.9,
d: 1.95 (2H, m, C2ꢀ-CH2), 2.40 (3H, s, CH3), 2.69 (2H, t, Jꢁ6.1 Hz, C1ꢀ- 1478.7, 1325.8. MS m/z: 513.2 (Mꢂ). Anal. Calcad for C25H29ClN6O2S: C,
CH2), 3.23 (2H, t, Jꢁ6.2 Hz, C2ꢀ-CH2), 4.23 (1H, br s, NH), 6.43 (1H, s, C6- 58.53; H, 5.70; N, 16.38. Found: C, 58.42; H, 5.59; N, 16.33.
H), 7.46 (2H, d, Jꢁ8.7 Hz, Ph-C2,6-2H), 7.57 (2H, d, Jꢁ8.7 Hz, Ph-C3,5-2H).
N-(3-Chlorophenyl)-5-methyl-2-(3-((5-(piperidin-1-ylmethyl)furan-2-
MS m/z: 370.0 (Mꢂ); Anal. Calcd for C16H15ClF3N5: C, 51.97; H, 4.09; N, yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (8) Pre-
18.94; Found: C, 51.93; H, 4.01; N, 18.91.
General Procedure for the Preparation of N-Anilino-2-(3-(ffuran-2-yl-
methylthio)propyl)-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-amines C3,5-2CH2), 2.02 (2H, m, C2ꢀ-CH2), 2.42 (3H, s, CH3), 2.61 (2H, t, Jꢁ6.9 Hz,
pared from 6a and piperidine, 65% yield. mp 166—168 °C. 1H-NMR
(DMSO-d6) d: 1.44 (2H, m, piperidinyl-C4-CH2), 1.68 (4H, br s, piperidinyl-
Furan-2-ylmethanethiol (8.6 g, 75 mmol) was added dropwise into a suspen-
sion of NaH (1.8 g 75 mmol) in dried DMF (80 ml) at room temperature.
C1ꢀ-CH2), 2.89 (2H, t, Jꢁ7.1 Hz, C3ꢀ-CH2), 2.99 (4H, br s, piperidinyl-C2,6
2CH2), 3.80 (2H, s, C5ꢀ-CH2), 4.19 (2H, s, NCH2), 6.32 (1H, br s, C3ꢅ-H),
-
After the addition, the mixture was stirred for 5 min, and then 5a—d 6.45 (1H, s, C6-H), 6.50 (1H, br s, C4ꢅ-H), 7.34 (1H, m, Ph-C2-H), 7.46—
(25 mmol) was added in one portion. The mixture was heated at 50 °C for
7.52 (3H, m, Ph-C4,5,6-3H). IR (KBr) cmꢆ1: 3445.7, 2948.3, 1620.4, 1533.9,
30 min and then poured into water. The brown oil which separated from 1479.0, 1329.1. MS m/z: 511.3 (Mꢂ). Anal. Calcd for C26H31ClN6OS: C,
water was triturated with diethyl ether. The resulting precipitate was col- 61.10; H, 6.11; N, 16.44. Found: C, 61.05; H, 6.15; N, 16.29.
lected by filtration, washed well with water and further purified by recrystal-
lization from ethyl acetate/cyclohexane to afford 6a—d as gray solid (80—
85%).
N-(3-Chlorophenyl)-5-methyl-2-(3-((5-(pyrrolidin-1-ylmethyl)furan-2-
yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (9) Pre-
pared from 6a and pyrrolidine, 69% yield. mp 179—180 °C. 1H-NMR
N-(3-Chlorophenyl)-2-(3-(ffuran-2-yl-methylthio)propyl)-5-methyl- (CDCl3) d: 1.83 (4H, m, pyrrodinyl-C3,4-2CH2), 2.14 (2H, m, C2ꢀ-CH2), 2.55
[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (6a) Prepared from 5a, 81% (3H, s, CH3), 2.63 (2H, t, Jꢁ7.1 Hz, C1ꢀ-CH2), 2.71 (4H, br s, pyrrodinyl-
yield. mp 148—150 °C. 1H-NMR (DMSO-d6) d: 1.99 (2H, m, C2ꢀ-CH2), C2,5-2CH2), 2.99 (2H, t, Jꢁ6.8 Hz, C3ꢀ-CH2), 3.72 (4H, br s, C5ꢀ-CH2,
2.41 (3H, s, CH3), 2.61 (2H, t, Jꢁ7.1 Hz, C1ꢀ-CH2), 2.88 (2H, t, Jꢁ7.1 Hz,
C3ꢀ-CH2), 3.72 (2H, s, C5ꢀ-CH2), 4.18 (1H, br s, NH), 6.04 (1H, d, Jꢁ2.7 Hz,
NCH2), 6.11 (1H, br s, C3ꢅ-H), 6.17 (1H, br s, C4ꢅ-H), 6.34 (1H, s, C6-H),
7.28 (1H, m, Ph-C2-H), 7.39—7.43 (3H, m, Ph-C4,5,6-3H). IR (KBr) cmꢆ1
:
C3ꢅ-H), 6.18 (1H, t, C4ꢅ-H), 6.44 (1H, s, C6-H), 7.11 (1H, d, Jꢁ1.9 Hz, C5ꢅ- 3443.6, 2963.8, 1609.5, 1575.9, 1479.2, 1329.1. MS m/z: 497.2 (Mꢂ). Anal.
H), 7.26 (1H, m, Ph-C2-H), 7.39—7.44 (3H, m, Ph-C4,5,6-3H). MS m/z: Calcd for C25H29ClN6OS: C, 60.41; H, 5.88; N, 16.91. Found: C, 60.35; H,
414.0 (Mꢂ); Anal. Calcd for C20H20ClN5OS: C, 58.03; H, 4.87; N, 16.92; 5.75; N, 16.86.
Found: C, 58.00; H, 4.82; N, 16.88.
N-(3-Chloro-4-fluorophenyl)-2-(3-(ffuran-2-yl-methylthio)propyl)-5-
N-(3-Chlorophenyl)-5-methyl-2-(3-((5-((4-methylpiperazin-1-
yl)methyl)furan-2-yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-

944
Vol. 56, No. 7
7-amine (10) Prepared from 6a and 4-methylpiperazine, 82% yield. mp C23H26ClFN6OS: C, 56.49; H, 5.36; N, 17.19. Found: C, 56.38; H, 5.25; N,
201—202 °C. 1H-NMR (CDCl3) d: 2.02 (2H, m, C2ꢀ-CH2), 2.42 (3H, s, 17.12.
NCH3), 2.57—2.63 (6H, m, C1ꢀ-CH2, piperazinyl-C3,5-2CH2), 2.72 (3H, s,
C5-CH3), 2.89 (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.16 (4H, br s, piperazinyl-C2,6
2CH2), 3.55 (2H, s, C5ꢀ-CH2), 3.76 (2H, s, NCH2), 6.21 (2H, m, C3ꢅ,4ꢅ-H),
6.45 (1H, s, C6-H), 7.34 (1H, m, Ph-C2-H), 7.46—7.52 (3H, m, Ph-C4,5,6
3H); IR (KBr) cmꢆ1: 3446.2, 2960.6, 1621.8, 1567.4, 1515.6, 1468.8,
5-Methyl-2-(3-((5-(morpholinomethyl)furan-2-yl)methylthio)propyl)-
-
N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine
1
(17) Prepared from 6c and morpholine, 57% yield. mp 185—187 °C. H-
-
NMR (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, CH3), 2.60 (6H,
br s, C1ꢀ-CH2, morpholino-C2,6-2CH2), 2.89 (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.60
1329.5. MS m/z: 526.4 (Mꢂ). Anal. Calcd for C26H32ClN7OS: C, 59.36; H, (4H, br s, morpholino-C3,5-2CH2), 3.72 (2H, s, C5ꢀ-CH2), 3.77 (2H, s,
6.13; N, 18.64. Found: C, 59.29; H, 6.05; N, 18.59.
NCH2), 6.18—6.28 (2H, m, C3ꢅ,4ꢅ-2H), 6.41 (1H, s, C6-H), 7.46 (2H, d,
N-(3-Chlorophenyl)-2-(3-((5-((dimethylamino)methyl)furan-2- Jꢁ8.7 Hz, Ph-C2,6-2H), 7.57 (2H, m, Jꢁ8.7 Hz, Ph-C3,5-2H). IR (KBr)
yl)methylthio)propyl)-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine cmꢆ1: 3447.5, 2963.8, 1610.5, 1575.4, 1478.8, 1329.0. MS m/z: 563.2 (Mꢂ).
(11) Prepared from 6a and dimethylamine, 55% yield. mp 163—164 °C.
Anal. Calcd for C26H29F3N6O3S: C, 55.51; H, 5.20; N, 14.94; Found: C,
1H-NMR (CDCl3) d: 2.15 (2H, m, C2ꢀ-CH2), 2.38 (6H, s, N(CH3)2), 2.55 55.47; H, 5.18; N, 14.89.
(3H, s, C5-CH3), 2.64 (2H, t, Jꢁ7.1 Hz, C1ꢀ-CH2), 2.99 (2H, t, Jꢁ7.2 Hz,
C3ꢀ-CH2), 3.63 (2H, s, C5ꢀ-CH2), 3.73 (2H, s, NCH2), 6.14 (1H, br s, C3ꢅ-H),
6.22 (1H, br s, C4ꢅ-H), 6.36 (1H, s, C6-H), 7.28 (1H, m, Ph-C2-H), 7.39—
5-Methyl-2-(3-((5-(piperidin-1-ylmethyl)furan-2-yl)methylthio)-
propyl)-N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-
7-amine (18) Prepared from 6c and piperidine, 49% yield. mp 177—
7.43 (3H, m, Ph-C4,5,6-3H); IR (KBr) cmꢆ1: 3443.5, 2925.9, 1609.8, 1566.9, 179 °C. 1H-NMR (DMSO-d6) d: 1.43 (2H, m, piperidinyl-C4-CH2), 1.65
1478.5, 1328.3. MS m/z: 471.1 (Mꢂ). Anal. Calcd for C23H27ClN6OS: C,
58.65; H, 5.78; N, 17.84. Found: C, 58.46; H, 5.83; N, 17.75.
(4H, br s, piperidinyl-C3,5-2CH2), 2.02 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, CH3),
2.61 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.89 (2H, t, Jꢁ7.1 Hz, C3ꢀ-CH2), 2.99 (4H,
br s, piperidinyl-C3,5-2CH2), 3.78 (2H, s, C5ꢀ-CH2), 4.06 (2H, s, NCH2), 6.29
N-(3-Chloro-4-fluorophenyl)-5-methyl-2-(3-((5-(morpholinomethyl)-
furan-2-yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine (1H, d, Jꢁ2.9 Hz, C3ꢅ-H), 6.42 (2H, br s, C4ꢅ-H, C6-H), 7.46 (2H, d,
1
(12) Prepared from 6b and morpholine, 72% yield. mp 182—183 °C. H-
NMR (CDCl3) d: 2.02 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, CH3), 2.60 (2H, br s,
Jꢁ8.6 Hz, Ph-C2,6-2H), 7.57 (2H, m, Jꢁ8.7 Hz, Ph-C3,5-2H); IR (KBr)
cmꢆ1: 3441.5, 2963.2, 1608.9, 1575.8, 1479.5, 1329.2. MS m/z: 561.2 (Mꢂ).
C1ꢀ-CH2), 2.88 (2H, br s, C3ꢀ-CH2), 2.91 (4H, br s, morpholino-C2,6-2CH2), Anal. Calcd for C27H31F3N6O2S: C, 57.84; H, 5.57; N, 14.99; Found: C,
3.72 (4H, br s, morpholino-C3,5-2CH2), 3.80 (2H, s, C5ꢀ-CH2), 4.10 (2H, s, 57.78; H, 5.51; N, 14.94.
NCH2), 6.31 (1H, br s, C3ꢅ-H), 6.36 (1H, br s, C4ꢅ-H), 6.46 (1H, s, C6-H),
5-Methyl-2-(3-((5-(pyrrolidin-1-ylmethyl)furan-2-yl)methylthio)-
7.52 (2H, m, Ph-C2,6-2H), 7.63 (1H, m, Ph-C5-H); IR (KBr) cmꢆ1: 3445.2, propyl)-N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-
2925.7, 1576.5 1496.0, 1478.5, 1328.6. MS m/z: 531.5 (Mꢂ). Anal. Calcd 7-amine (19) Prepared from 6c and pyrrolidine, 45% yield. mp 170—
for C25H28ClFN6O2S: C, 56.54; H, 5.31; N, 15.83. Found: C, 56.35; H, 5.23; 172 °C. 1H-NMR (DMSO-d6) d: 1.89 (4H, m, pyrrodinyl-C3,4-2CH2), 2.02
N, 15.69.
(2H, m, C2ꢀ-CH2), 2.42 (3H, s, CH3), 2.62 (2H, t, Jꢁ7.1 Hz, C1ꢀ-CH2), 2.89
N-(3-Chloro-4-fluorophenyl)-5-methyl-2-(3-((5-(piperidin-1-ylmethyl)- (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.20 (4H, br s, pyrrodinyl-C2,5-2CH2), 3.78 (2H,
furan-2-yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine s, C5ꢀ-CH2), 3.89 (2H, s, NCH2), 6.30 (1H, s, C3ꢅ-H), 6.42 (1H, s, C6-H),
(13) Prepared from 6b and piperidine, 75% yield. mp 180—182 °C.
6.53 (1H, s, C4ꢅ-H), 7.46 (2H, d, Jꢁ8.5 Hz, Ph-C2,6-2H), 7.57 (2H, m,
1H-NMR (CDCl3) d: 1.45 (2H, m, piperidinyl-C4-CH2), 1.67 (4H, m, Jꢁ8.7 Hz, Ph-C3,5-2H); IR (KBr) cmꢆ1: 3444.2, 2964.6, 1609.6, 1573.6,
piperidinyl-C3,5-2CH2), 2.02 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, CH3), 2.61 (2H, 1478.6, 1328.1. MS m/z: 547.2 (Mꢂ). Anal. Calcd for C26H29F3N6O2S: C,
t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.89 (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 2.95 (4H, br s,
piperidinyl-C2,6-2CH2), 3.80 (2H, s, C5ꢀ-CH2), 4.15 (2H, s, NCH2), 6.30 (1H,
d, Jꢁ3.3 Hz, C3ꢅ-H), 6.36 (1H, s, C6-H), 6.48 (1H, d, Jꢁ3.3 Hz, C4ꢅ-H),
57.13; H, 5.35; N, 15.37; Found: C, 57.08; H, 5.30; N, 15.32.
5-Methyl-2-(3-((5-((4-methylpiperazin-1-yl)methyl)furan-2-yl)-
methylthio)propyl)-N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-
a]pyrimidin-7-amine (20) Prepared from 6c and 4-methylpiperazine, 67%
yield. mp 189—191 °C. 1H-NMR (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-CH2),
7.45—7.53 (2H, m, Ph-C2,6-2H), 7.68 (1H, m, Ph-C5-H). IR (KBr) cmꢆ1
:
3443.5, 2947.7, 1623.7, 1575.9, 1494.1, 1478.5, 1320.9. MS m/z: 529.5
(Mꢂ). Anal. Calcd for C26H30ClFN6OS: C, 59.02; H, 5.72; N, 15.88. Found: 2.41 (3H, s, CH3), 2.60 (2H, t, Jꢁ7.1 Hz, C1ꢀ-CH2), 2.72 (7H, br s, piper-
C, 58.86; H, 5.62; N, 15.75.
azinyl-C3,5-2CH2, NCH3), 2.89 (2H, t, Jꢁ7.1 Hz, C3ꢀ-CH2), 3.14 (4H, br s,
N-(3-Chloro-4-fluorophenyl)-5-methyl-2-(3-((5-(pyrrolidin-1-yl-
piperazinyl-C2,6-2CH2), 3.55 (2H, s, C5ꢀ-CH2), 3.76 (2H, s, NCH2), 6.21 (2H,
methyl)furan-2-yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7- br s, C3ꢅ,4ꢅ-2H), 6.42 (1H, s, C6-H), 7.46 (2H, d, Jꢁ8.5 Hz, Ph-C2,6-2H), 7.57
amine (14) Prepared from 6b and pyrrolidine, 75% yield. mp 175—
(2H, m, Jꢁ8.8 Hz, Ph-C3,5-2H); IR (KBr) cmꢆ1: 3441.4, 2961.5, 1608.5,
178 °C. 1H-NMR (DMSO-d6) d: 1.89 (4H, m, pyrrodinyl-C3,4-2CH2), 2.02 1575.4, 1477.8, 1329.2. MS m/z: 576.1 (Mꢂ). Anal. Calcd for
(2H, m, C2ꢀ-CH2), 2.41 (3H, s, CH3), 2.61 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.89 C27H32F3N7O2S: C, 56.33; H, 5.60; N, 17.03; Found: C, 56.27; H, 5.54; N,
(2H, t, Jꢁ7.1 Hz, C3ꢀ-CH2), 3.20 (4H, br s, pyrrodinyl-C2,3-2CH2), 3.81 (2H, 16.94.
s, C5ꢀ-CH2), 4.35 (2H, s, NCH2), 6.33 (1H, s, Jꢁ2.9 Hz, C3ꢅ-H), 6.36 (1H, s,
C6-H), 6.52 (1H, s, Jꢁ2.8 Hz, C4ꢅ-H), 7.48—7.54 (2H, m, Ph-C2,6-2H), 7.67
5-Methyl-2-(3-((5-(morpholinomethyl)furan-2-yl)methylthio)propyl)-
N-(4-(trifluoromethyl)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine
1
(1H, m, Ph-C5-H). IR (KBr) cmꢆ1: 3446.1, 2966.8, 1609.4, 1573.7, 1479.6, (21) Prepared from 6d and morpholine, 59% yield. mp 180—182 °C. H-
1327.8. MS m/z: 515.4 (Mꢂ). Anal. Calcd for C25H28ClFN6OS: C, 58.30; H, NMR (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-CH2), 2.44 (3H, s, CH3), 2.59 (2H,
5.48; N, 16.32. Found: C, 58.18; H, 5.40; N, 16.21.
br s, C1ꢀ-CH2), 2.63 (4H, br s, morpholino-C2,6-2CH2), 2.88 (2H, t, Jꢁ7.2 Hz,
N-(3-Chloro-4-fluorophenyl)-5-methyl-2-(3-((5-((4-methylpiperazin-1-
C3ꢀ-CH2), 3.61 (4H, br s, morpholino-C3,5-2CH2), 3.72 (2H, s, C5ꢀ-CH2), 4.06
yl)methyl)furan-2-yl)methylthio)propyl)-[1,2,4]triazolo[1,5-a]pyrimidin- (2H, s, NCH2), 6.25—6.28 (2H, m, C3ꢅ,4ꢅ-2H), 6.63 (1H, s, C6-H), 7.67 (2H,
7-amine (15) Prepared from 6b and 4-methylpiperazine, 80% yield. mp d, Jꢁ8.3 Hz, Ph-C2,6-2H), 7.82 (2H, d, Jꢁ8.5 Hz, Ph-C3,5-2H). IR (KBr)
1
195—196 °C. H-NMR (DMSO-d6) d: 2.01 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, cmꢆ1: 3446.6, 2963.5, 1609.5, 1574.8, 1479.5, 1328.4. MS m/z: 547.3 (Mꢂ).
C5-CH3), 2.59 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.72 (7H, br s, NCH3, piper- Anal. Calcd for C26H29F3N6O2S: C, 57.13; H, 5.35; N, 15.37; Found: C,
azinyl-C3,5-2CH2), 2.88 (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.13 (4H, br s, piper-
azinyl-C2,6-2CH2), 3.55 (2H, s, C5ꢀ-CH2), 3.76 (2H, s, NCH2), 6.20 (1H, d,
Jꢁ3.0 Hz, C3ꢅ-H), 6.22 (1H, d, Jꢁ3.3 Hz, C4ꢅ-H), 6.36 (1H, s, C6-H), 7.45—
57.10; H, 5.33; N, 15.32.
5-Methyl-2-(3-((5-(piperidin-1-ylmethyl)furan-2-yl)methylthio)-
propyl)-N-(4-(trifluoromethyl)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-
7.53 (2H, m, Ph-C2,6-2H), 7.67 (1H, m, Ph-C5-H). IR (KBr) cmꢆ1: 3442.9, amine (22) Prepared from 6d and piperidine, 51% yield. mp 173—174 °C.
3008.2, 1574.5, 1495.3, 1478.2, 1328.2. MS m/z: 544.5 (Mꢂ). Anal. Calcd
for C26H31ClFN7OS: C, 57.39; H, 5.74; N, 18.02. Found: C, 57.25; H, 5.62; piperidinyl-C3, 5-2CH2), 2.03 (2H, m, C2ꢀ-CH2), 2.50 (3H, s, CH3), 2.61 (2H,
1H-NMR (DMSO-d6) d: 1.46 (2H, m, piperidinyl-C4-CH2), 1.69 (4H, m,
N, 17.95.
N-(3-Chloro-4-fluorophenyl)-2-(3-((5-((dimethylamino)methyl)furan-
t, Jꢁ7.3 Hz, C1ꢀ-CH2), 2.90 (2H, t, Jꢁ7.1 Hz, C3ꢀ-CH2), 3.00 (4H, br s,
piperidinyl-C2,6-2CH2), 3.80 (2H, s, C5ꢀ-CH2), 4.23 (2H, s, NCH2), 6.33 (1H,
2-yl)methylthio)propyl)-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7- br s, C3ꢅ-H), 6.51 (1H, br s, C4ꢅ-H), 6.63 (1H, s, C6-H), 7.68 (2H, d,
amine (16) Prepared from 6b and dimethylamine, 70% yield. mp 170—
Jꢁ8.3 Hz, Ph-C2,6-2H), 7.82 (2H, d, Jꢁ8.5 Hz, Ph-C3,5-2H). IR (KBr) cmꢆ1
172 °C. 1H-NMR (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-CH2), 2.41 (3H, s, C5- 3443.9, 2963.9, 1608.6, 1575.3, 1477.5, 1328.4. MS m/z: 545.2 (Mꢂ). Anal.
CH3), 2.61 (2H, t, Jꢁ6.9 Hz, C1ꢀ-CH2), 2.69 (6H, s, N(CH3)2), 2.89 (2H, t, Calcd for C27H31F3N6OS: C, 59.54; H, 5.74; N, 15.43; Found: C, 59.49; H,
Jꢁ7.2 Hz, C3ꢀ-CH2), 3.81 (2H, s, C5ꢀ-CH2), 4.28 (2H, s, NCH2), 6.34 (1H, d, 5.70; N, 15.38.
:
Jꢁ2.9 Hz, C3ꢅ-H), 6.36 (1H, s, C6-H), 6.56 (1H, d, Jꢁ3.0 Hz, C4ꢅ-H), 7.47—
5-Methyl-2-(3-((5-(pyrrolidin-1-ylmethyl)furan-2-yl)methylthio)-
7.56 (2H, m, Ph-C2,6-2H), 7.67 (1H, m, Ph-C5-H). IR (KBr) cmꢆ1: 3446.5, propyl)-N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-a]pyrimidin-
2925.2, 1576.4, 1496.3, 1430.1. MS m/z: 489.1 (Mꢂ). Anal. Calcd for 7-amine (23) Prepared from 6d and pyrrolidine, 58% yield. mp 163—

July 2008
945
1
each well, and the absorbency at 492 nm (for absorbance of MTT formazan)
and 630 nm (for the reference wavelength) was measured with the ELISA
reader.
The cytotoxicity effect was expressed as the IC50, which was calculated by
Bliss.
165 °C; H-NMR (DMSO-d6) d: 1.89 (4H, br s, pyrrodinyl-C3,4-2CH2), 2.02
(2H, m, C2ꢀ-CH2), 2.42 (3H, s, CH3), 2.61 (2H, t, Jꢁ7.5 Hz, C1ꢀ-CH2), 2.9
(2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.21 (4H, br s, pyrrodinyl-C2,5-2CH2), 3.81 (2H,
s, C5ꢀ-CH2), 4.36 (2H, s, NCH2), 6.33 (1H, d, Jꢁ3.0 Hz, C3ꢅ-H), 6.47 (1H, s,
C6-H), 6.53 (1H, d, Jꢁ3.0 Hz, C4ꢅ-H), 7.68 (2H, d, Jꢁ8.3 Hz, Ph-C2,6-2H),
7.82 (2H, d, Jꢁ8.5 Hz, Ph-C3,5-2H). IR (KBr) cmꢆ1: 3445.1, 2975.2, 1608.3,
1574.3, 1476.1, 1328.5. MS m/z: 531.1 (Mꢂ). Anal. Calcd for
C26H29F3N6OS: C, 58.85; H, 5.51; N, 15.84; Found: C, 58.81; H, 5.47; N,
15.79.
5-Methyl-2-(3-((5-((4-methylpiperazin-1-yl)methyl)furan-2-yl)-
methylthio)propyl)-N-(4-(trifluoromethoxy)phenyl)-[1,2,4]triazolo[1,5-
a]pyrimidin-7-amine (24) Prepared from 6d and 4-methylpiperazine,
65% yield. mp 188—189 °C; 1H-NMR (DMSO-d6) d: 2.02 (2H, m, C2ꢀ-
CH2), 2.44 (3H, s, C5-CH3), 2.59 (2H, t, Jꢁ7.2 Hz, C1ꢀ-CH2), 2.72 (7H, br s,
piperazinyl-C3,5-2CH2, NCH3), 2.90 (2H, t, Jꢁ7.2 Hz, C3ꢀ-CH2), 3.15 (4H,
br s, piperazinyl-C2,6-2CH2), 3.55 (2H, s, C5ꢀ-CH2), 3.76 (2H, s, NCH2), 6.21
(2H, br s, C3ꢅ,4ꢅ-2H), 6.63 (1H, s, C6-H), 7.68 (2H, d, Jꢁ8.1 Hz, Ph-C2,6-2H),
7.82 (2H, d, Jꢁ8.4 Hz, Ph-C3,5-2H); IR (KBr) cmꢆ1: 3445.7, 2969.4, 1609.7,
1576.8, 1479.8, 1329.0. MS m/z: 559.9 (Mꢂ). Anal. Calcd for
C27H32F3N7OS: C, 57.95; H, 5.76; N, 17.52; Found: C, 57.91; H, 5.72; N,
15.49.
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Evaluation of Biological Activity The anti-tumor activities of com-
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Approximately 4ꢄ103 cells, suspended in MEM medium, were plated
onto each well of a 96-well plate and incubated in 5% CO2 at 37 °C for 24 h.
The test compounds at indicated final concentrations were added to the cul-
ture medium and the cell cultures were continued for 72 h. Fresh MTT was
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