Non-nucleoside HIV-1 reverse transcriptase inhibitors. Part 11: Structural modulations of diaryltriazines with potent anti-HIV activity

Article abstract of DOI:10.1016/j.ejmech.2007.08.001

A series of novel 6-naphthyloxy substituted DATA analogues bearing different substituents on the C-6 position of triazine ring were synthesized and evaluated for their in vitro anti-HIV activity in MT-4 cells. The results demonstrated that most of the com

Full text of DOI:10.1016/j.ejmech.2007.08.001

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European Journal of Medicinal Chemistry 43 (2008) 1230e1236
http://www.elsevier.com/locate/ejmech
Original article
Non-nucleoside HIV-1 reverse transcriptase inhibitors.
Part 11: Structural modulations of diaryltriazines with
potent anti-HIV activity*
d
d
Yuan-Zhen Xiong a, Fen-Er Chen a,b,c, , Jan Balzarini , Erik De Clercq ,
*
Christophe Pannecouque d
a School of Pharmacy, Fudan University, Shanghai 200031, PR China
b Department of Chemistry, Fudan University, Shanghai 200433, PR China
c Institute of Biomedical Science, Fudan University, Shanghai 200031, PR China
d Rega Institute for Medical Research, Katholieke Universiteit Leuven, 10 Minderbroedersstraat, B-3000 Leuven, Belgium
Received 15 May 2007; received in revised form 27 July 2007; accepted 4 August 2007
Available online 11 August 2007
Abstract
A series of novel 6-naphthyloxy substituted DATA analogues bearing different substituents on the C-6 position of triazine ring were synthe-
sized and evaluated for their in vitro anti-HIV activity in MT-4 cells. The results demonstrated that most of the compounds in this series are
potent activity against HIV-1 with moderate to high selectivity. Among these analogues, two compounds exhibited excellent effect in inhibiting
HIV-1 replication at nanomolar concentration (for compound 9h: IC50 ¼ 9.3 nM, SI ¼ 15,385; for compound 9i: IC50 ¼ 9.4 nM, SI ¼ 14,094),
which are about 15-fold more active than nevirapine. In addition, several compounds are active against both HIV-1 and HIV-2, whose mech-
anism may be different from typical NNRTIs.
Ó 2007 Elsevier Masson SAS. All rights reserved.
Keywords: Non-nucleoside HIV-1 reverse transcriptase inhibitors; Diaryltriazine; Anti-HIV activity
1. Introduction
Our recent 3D-QSAR [4] on the binding mode of DATAs
with HIV-1 RT indicated that increasing volume of substituent
on C-6 of triazine ring was beneficial for strengthening pep
stacking interaction between inhibitor and Tyr188 or Tyr181
of RT. This background prompted us to further explore novel
DATAs bearing a- or b-naphthyloxy group at C-6 position in
triazine ring. In this paper, a series of novel DATA analogues
were synthesized and evaluated for anti-HIV activity.
The reverse transcriptase (RT) of the human immunodefi-
ciency virus type 1 (HIV-1) is a key target for inhibition
of HIV-1 replication, the RT can be inhibited by two classes of
drug belonging either to the nucleoside reverse transcriptase in-
hibitors (NRTIs) or to the non-nucleoside reverse transcriptase
inhibitors (NNRTIs). NNRTIs have become key components
in the combination regiments of cocktail therapy. Within the
NNRTI category, diaryltriazine analogues (DATAs) are a class
of interesting compounds which are highly effective against
wild-type and various mutant strains of HIV-1 [2,3] (Fig. 1).
2. Results and discussion
2.1. Chemistry
*
See Ref. [1].
The synthesis of the novel designed compounds is
outlined in Scheme 1. The known 4-(4,6-dichloro-1,3,5-
triazine-2-yl)aminobenzonitrile (5) was easily prepared from
* Corresponding author. Institute of Biomedical Science, Fudan University,
Shanghai 200031, PR China. Tel./fax: þ86 21 65643811.
E-mail address: rfchen@fudan.edu.cn (F.-E. Chen).
0223-5234/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2007.08.001

Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
1231
NH
Cl
14,094, respectively). An improvement of the biological pro-
file was obtained by the introduction of halogen substituents
(Cl and Br) to the naphthyl ring. The compounds 9h and 9i
having bromo-substituted on the naphthyl ring are more potent
than the corresponding chloro-substituted compounds (9o and
9p). It is noteworthy that decrease in potency was observed
when NH2 group was N-alkylated by various alkyl groups
(Me, Et, n-Pr, i-Pr). Further replacement of NH2 group with
N3 in 8e converted into compound 9r, this compound
displayed a lower level of cytotoxicity with no effect upon
antiviral activity.
N
X
Y
H
N
O
N
R
N
N
CN
N
N
Cl
CN
R=2,4,6-substitution or benzol
Y=O,NH
X=substituted amine, N3 or NH2
NH2
2
1
Br
H
N
O
H
N
N
N
O
N
N
Br
CN
N
N
CN
NH2
NH2
Besides the anti-HIV-1 activity, all the compounds were
also evaluated activity against HIV-2 ROD in MT-4 cells, it
was found that most of the compounds showed less activity
against HIV-2 in comparison with that against HIV-1.
4
3
Fig. 1. The structure of DATAs.
the 2,4,6-trichloro-1,3,5-triazine and 4-aminobenzonitrile fol-
lowing the reported method [5,6]. The disubstituted 6aeb and
7aee were obtained in 50e55% upon treatment of the corre-
sponding substituted a- or b-naphthol with 5 in the presence
of 60% NaH at 50e60 ꢀC. Condensation of 6aeb and 7aee
with appropriate primary amines in 1,4-dioxane at 60e70 ꢀC
provided target compounds 8aeg and 9aeq in 30e40% yield.
Another target compound 9r was synthesized by reaction of 7c
with NaN3 in 1,4-dioxane at 90 ꢀC. All the synthesized com-
pounds were well characterized by spectroscopic data as IR,
MS, NMR and elemental analysis.
3. Conclusion
In summary, we designed, synthesized and evaluated a series
of novel DATA analogues, most of which have potent activities
against HIV-1. The results provided useful indicators for guid-
ing further rational design of new inhibitors for the treatment
of AIDS. It also afforded information to the deep research
on the QSAR and the ongoing investigation of the NNRTI
binding site.
2.2. Anti-HIV activity
4. Experimental protocols
All newly synthesized compounds (8aeg, 9aer) were eval-
uated as previously described [7] on MT-4 cells for anti-HIV
activity and cytotoxicity, in comparison with nevirapine and
DDI used as reference drugs, and the results are summarized
in Table 1. Among all the newly disclosed DATAs, compounds
9h and 9i were the most potent inhibitors of HIV-1 replication
of the series (IC50 ¼ 0.0093 and 0.0094 mM, respectively),
coupled with the highest selectivity index (SI ¼ 15,385 and
4.1. Chemistry
Melting points were measured on a WRS-1 digital melting
point apparatus and are uncorrected. IR spectra (KBr) were re-
corded on a JASCO FT/IR-4200 instrument. 1H NMR and 13
NMR spectra were measured on a Brucker AV 400 MHz spec-
trometer in DMSO-d6. Chemical shifts are expressed in ppm
downfield from TMS, which was used as an internal standard.
C
Scheme 1. Reagents and conditions: (a) p-aminobenzonitrile, Et3N, THF, 0e5 ꢀC; (b) a-naphthol, 60%NaH, anhydrous THF, N2, 50e60 ꢀC; (c) b-naphthol,
60%NaH, anhydrous THF, N2, 50e60 ꢀC; (d) NH3 or RNH2, 1,4-dioxane, 60e70 ꢀC; and (e) NaN3, 1,4-dioxane, 90 ꢀC.

1232
Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
Table 1
Anti-HIV-1 and HIV-2 activity of a- and b-DATA derivatives in MT-4 cells
R2
H
N
H
O
N
O
N
N
N
N
N
N
CN
CN
R3
R1
R4
R4
8a-g
9a-r
Compound
R1
R2
R3
R4
IC50 (mM)a
CC50 (mM)b
SIc (IIIB)
HIV-1 IIIB
HIV-2 ROD
8a
8b
8c
8d
8e
H
NHMe
NH2
0.186 ꢁ 0.0573
0.107 ꢁ 0.0584
2.7 ꢁ 0.277
>30.33
>39.06
>73.15
>196.89
30.33 ꢁ 11.5
39.07 ꢁ 4.55
29.46 ꢁ 0.93
196.9 ꢁ 8.08
237
163
364
H
H
n-PrNH
NHMe
NH2
11
Cl
Cl
0.093 ꢁ 0.04
0.062 ꢁ 0.0244
2111
3775
ꢃ12.60 ꢁ 3.96
8f
Cl
Cl
NHEt
n-PrNH
NHMe
NH2
0.733 ꢁ 0.606
1.63 ꢁ 0.598
0.26 ꢁ 0.0144
0.09 ꢁ 0.0542
0.156 ꢁ 0.0046
0.256 ꢁ 0.116
0.693 ꢁ 0.103
>207.7
45.58
207.7 ꢁ 23
285
111
968
471
8g
9a
9b
181.6 ꢁ 10.74
250 ꢁ 24.2
H
H
H
H
>250.76
ꢃ11.47
>74.47
42.23 ꢁ 4.27
74.4 ꢁ 9.19
134.44 ꢁ 23.38
ꢃ209
9c
9d
9e
Br
Br
Br
Br
Br
Br
NHEt
n-PrNH
i-PrNH
477
524
6.59 ꢁ 0.31
9.71 ꢁ 5.67
>302
9f
Br
H
H
i-PrNH
NHMe
NHMe
1.065 ꢁ 0.465
0.284 ꢁ 0.029
0.0093 ꢁ 0.0032
>41.54
>193.9
ꢃ28.19
41.54 ꢁ 8.72
193.9 ꢁ 17.76
143.2 ꢁ 8.55
39
685
9g
9h
Br
H
Br
15,385
9i
9j
Br
Br
H
H
NH2
n-PrNH
0.0094 ꢁ 0.0021
20.2 ꢁ 4.68
133 ꢁ 14.69
14,094
>1294
0.203 ꢁ 0.132
ꢃ58.3
>263.2
9k
9l
Cl
Cl
H
H
NHEt
n-PrNH
0.114 ꢁ 0.0521
0.187 ꢁ 0.0134
15.95 ꢁ 6.33
ꢃ43.62
187.93 ꢁ 4.58
>290
1642
>1547
9m
9n
9o
Br
Br
Cl
Cl
Br
Br
H
NHMe
NH2
0.0184 ꢁ 0.008
0.0195 ꢁ 0.0107
0.0118 ꢁ 0.0036
0.0287 ꢁ 0.0246
>91.85
10.47
92.83 ꢁ 14.96
244
5018
12,475
14,412
2872
NHMe
NH2
>170.6
ꢃ5.3
170.6 ꢁ 12.74
32.15
9p
H
9q
9r
H
Cl
Br
H
NH2
N3
0.0808 ꢁ 0.0050
0.06 ꢁ 0.0289
0.25
19.7 ꢁ 1.64
243
256.32 ꢁ 37.05
>200
3019
4270
>800
ꢃ98
6.17 ꢁ 0.84
Nevirapine
DDI
5.37
2.71
ꢃ529
a
Concentration required to protect the cell against viral cytopathogenicity by 50% in MT-4 cells.
Concentration that reduces the MT-4 cell viability by 50%.
b
c
Selectivity index: ratio CC50/IC50
.
Mass spectra were obtained on an Agilent MS/5975 mass
spectrometer. Elemental analysis was performed on a Carlo
Erba 1106 instrument and the results of elemental analysis
for C, H, N, Cl and Br were within ꢁ0.4% of the theoretical
values. All chemicals and solvents were reagent grade purified
by standard methods prior to use.
4.1.1.1. 4-[4-Chloro-6-(1-naphthoxy)-1,3,5-triazine-2-yl]ami-
nobenzonitrile (6a). Yield: 1.ꢂ951 g, 50.67%; m.p. 224.0e
224.5 ꢀC; IR (KBr): 2220 cm
;
1H NMR (DMSO-d6) d:
7.27e8.10 (m, 11H, phenyl, naphthyl), 11.10 (s, 1H, NH);
13C NMR (DMSO-d6) d: 105.47 (CN), 118.31, 118.53,
119.88, 120.33, 120.78, 121.46, 125.74, 126.19, 126.41,
127.09, 128.15, 132.72, 133.17, 134.29, 141.95, 147.35 (phe-
nyl, naphthyl), 164.92, 170.54, 170.99 (triazine). Anal.
(C20H12N5ClO) C, H, N, Cl; EIMS m/z: 373 (Mþ).
4.1.1. General procedure for preparation of 6aeb and 7aee
To a stirred solution of a- or b-naphthol compounds
(11.3 mmol) in anhydrous THF (100 ml) was added 60%
NaH (0.452 g, 11.3 mol) at room temperature under a nitrogen
atmosphere, the resulting solution was stirred at this tempera-
ture for 30 min, 5 (3.03 g, 11.3 mmol) was added into the
reaction mixture. Stirring was continued for another 4 h at
50e60 ꢀC. The precipitate was collected by filtration, washed
with water, and recrystallized from methanol to afford the
desired products 6aeb and 7aee.
4.1.1.2. 4-[4-Chloro-6-(4-chloro-1-naphthoxy)-1,3,5-triazine-
2-yl]aminobenzonitrile (6b). Yield: 2.26 g, 52.87%; m.p.
274.2 ꢀC (dec); IR (KBr): 2220 cmꢂ1 (CN); 1H NMR
(DMSO-d6) d: 7.27e8.10 (m, 10H, phenyl, naphthyl), 11.14
(s, 1H, NH); 13C NMR (DMSO-d6) d: 105.47 (CN), 118.31,
118.53, 119.88, 120.33, 120.78, 121.46, 125.74, 126.19,
126.41, 127.09, 128.15, 132.72, 133.17, 134.29, 141.95,

Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
1233
147.35 (phenyl, naphthyl), 164.92, 170.54, 170.99 (triazine).
Anal. (C20H11N5Cl2O) C, H, N, Br, Cl; EIMS m/z: 407 (Mþ).
60e90 ꢀC for 1e4 h, then precipitate took place, the solid was
collected by filtration, dissolved in AcOEt (20 ml), washed
with 4% NaOH, Sat. NaHCO3, and brine, respectively, dried
(MgSO4), the organic layer was concentrated to give crude
products, which were recrystallized from MeCN to afford
the desired products 8aeg and 9aer.
4.1.1.3.
4-[4-Chloro-6-(2-naphthoxy)-1,3,5-triazine-2-yl]
aminobenzonitrile (7a). Yield: 2.00 g, 51.34%; m.p. 226.3 ꢀC
(dec); IR (KBr): 2220 cmꢂ1 (CN); H NMR (DMSO-d6) d:
7.27e8.10 (m, 11H, phenyl, naphthyl), 11.28 (s, 1H, NH); 13
1
C
NMR (DMSO-d6) d: 105.47 (CN), 118.31, 118.53, 119.88,
120.33, 120.78, 121.46, 125.74, 126.19, 126.41, 127.09,
128.15, 132.72, 133.17, 134.29, 141.95, 147.35 (phenyl, naph-
thyl), 164.92, 170.54, 170.99 (triazine). Anal. (C20H12N5OCl)
C, H, N, Cl; EIMS m/z: 373 (Mþ).
4.1.2.1. 4-[4-Methylamino-6-(1-naphthoxy)-1,3,5-triazine-2-yl]
aminobenzonitrile (8a). Yield: 0.16 g, 32.1%; m.p. 223.6e
226.2 ꢀC; 1H NMR (DMSO-d6) d: 2.8 (dd, 3J ¼ 4.4 Hz,
CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e8.18 (m, 7H, naph-
thyl), 9.92 (s, 1H, NHCH3), 10.07 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 30.03 (CH3), 106.19 (CN), 121.15, 121.95,
122.14, 123.91, 128.55, 128.66, 129.23, 129.61, 130.63,
135.14, 135.34, 137.06, 146.78, 150.68 (phenyl, naphthyl),
168.01, 169.96, 173.38 (triazine). Anal. (C21H16N6O) C, H,
N; EIMS m/z: 368 (Mþ).
4.1.1.4. 4-[4-Chloro-6-(1,6-dibromo-2-naphthoxy)-1,3,5-tri-
azine-2-yl]aminobenzonitrile (7b). Yield:ꢂ12.88 g, 50.89%;
1
m.p. 256.3e259.1 ꢀC; IR (KBr): 2220 cm (CN); H NMR
(DMSO-d6) d: 7.27e8.10 (m, 9H, phenyl, naphthyl), 11.08
(s, 1H, NH); 13C NMR (DMSO-d6) d: 105.23 (CN), 114.36,
118.53, 120.00, 123.45, 128.85, 130.08, 130.80, 131.03,
131.50, 132.50, 132.80, 133.05, 133.27, 141.86, 142.60,
147.40 (phenyl, naphthyl), 164.69, 165.92, 170.34 (triazine).
Anal. (C20H10N5OBr2Cl) C, H, N, Br, Cl; EIMS m/z: 531 (Mþ).
4.1.2.2. 4-[4-Amino-6-(1-naphthoxy)-1,3,5-triazine-2-yl]ami-
nobenzonitrile (8b). Yield: 0.162 g, 33.5%; m.p. 213.3e
1
213.6 ꢀC; H NMR (DMSO-d6) d: 2.49 (s, 2H, NH2), 7.25e
7.42 (m, 4H, phenyl), 7.49e8.00 (m, 7H, naphthyl), 10.02
(s, 1H, NH); 13C NMR (DMSO-d6) d: 103.74 (CN), 118.74,
119.87, 122.11, 125.93, 126.38, 126.83, 127.05, 127.40,
127.56, 128.42, 133.06, 134.76, 144.59, 148.63 (phenyl, naph-
thyl), 165.94, 167.73, 171.10 (triazine). Anal. (C20H14N6O) C,
H, N; EIMS m/z: 354 (Mþ).
4.1.1.5. 4-[4-Chloro-6-(1-chloro-2-naphthoxy)-1,3,5-triazine-2-yl)
aminobenzonitrile (7c). Yield: 2.20, 51.47%; m.p. 259.9 ꢀC
1
(dec); IR (KBr): 2221 cmꢂ1 (CN); H NMR (DMSO-d6) d:
7.23e8.27 (m, 10H, phenyl, naphthyl), 11.32 (s, 1H, NH);
13C NMR (DMSO-d6) d: 105.15 (CN), 117.50, 118.20,
120.80, 121.93, 122.11, 124.96, 127.93, 128.70, 129.10,
129.62, 130.97, 132.10, 133.20, 134.20, 141.641, 145.49 (phe-
nyl, naphthyl), 163.77, 164.93, 170.22 (triazine). Anal.
(C20H11N5OCl2) C, H, N, Cl; EIMS m/z: 407 (Mþ).
4.1.2.3. 4-[4-n-Propylamino-6-(1-naphthoxy)-1,3,5-triazine-2-
y]aminobenzonitrile (8c). Yield: 0.185 g, 34.1%; m.p.
204 ꢀC (dec); 1H NMR (DMSO-d6) d: 0.88 (t, J ¼ 7.6 Hz,
3H, CH3), 1.58 (m, 2H, CH2CH2CH3), 3.31 (m, 2H,
CH2CH2CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e8.18 (m,
7H, naphthyl), 9.92 (s, 1H, NHCH3), 10.07 (s, 1H, NH); 13C
NMR (DMSO-d6) d: 11.79 (CH3), 22.48 (CH2), 42.52
(CH2), 104.08 (CN), 118.74, 119.87, 121.67, 125.93, 126.12,
126.83, 127.06, 127.51, 128.63, 126.83, 132.90, 135.15,
144.59, 148.41 (phenyl, naphthyl), 165.97, 167.85, 171.13 (tri-
azine). Anal. (C23H20N6O) C, H, N; EIMS m/z: 396 (Mþ).
4.1.1.6. 4-[4-Chloro-6-(1-bromo-2-naphthoxy)-1,3,5-triazine-
2-yl]aminobenzonitrile (7d). Yield: 2.ꢂ515 g, 53.38%; m.p.
214.4e216.0 ꢀC; IR (KBr): 2223 cm
(CN); 1H NMR
(DMSO-d6) d: 7.27e8.10 (m, 10H, phenyl, naphthyl), 11.18
(s, 1H, NH); 13C NMR (DMSO-d6) d: 105.47 (CN), 118.31,
118.53, 119.88, 120.33, 120.78, 121.46, 125.74, 126.19,
126.41, 127.09, 128.15, 132.72, 133.17, 134.29, 141.95,
147.35 (phenyl, naphthyl), 164.95, 170.22, 170.99 (triazine).
Anal. (C20H11N5OBrCl) C, H, N, Cl, Br; EIMS m/z: 453 (Mþ).
4.1.2.4. 4-[4-Methylamino-6-(4-chloro-1-naphthoxy)-1,3,5-tri-
azine-2-yl]aminobenzonitrile (8d). Yield: 0.200 g, 36.3%;
m.p. 276.4 ꢀC (dec); 1H NMR (DMSO-d6) d: 0.88 (dd,
J ¼ 4.8 Hz, 3H CH3), 739e8.34 (m, 10H, phenyl, naphthyl),
9.91 (s, 1H, NHCH3), 10.09 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 28.3 (CH3), 104.08 (CN), 119.32, 119.71,
119.82, 120.02, 122.56, 124.71, 126.35, 126.82, 127.53,
128.23, 128.61, 128.93, 144.64, 147.92 (phenyl, naphthyl),
165.97, 167.82, 171.13 (triazine). Anal. (C21H15ClN6O) C,
H, N, Cl; EIMS m/z: 402 (Mþ).
4.1.1.7. 4-[4-Chloro-6-(6-bromo-2-naphthoxy)-1,3,5-triazine-
2-yl]aminobenzonitrile (7e). Yield: 2.52 g, 52.67%; m.p.
208.6 ꢀC (dec); IR (KBr): 2225 cmꢂ1 (CN); 1H NMR
(DMSO-d6) d: 7.43e8.33 (m, 10H, phenyl, naphthyl), 11.29
(s, 1H, NH); 13C NMR (DMSO-d6) d: 104.45 (CN), 118.30,
118.50, 118.81, 120.05, 120.13, 122.80, 122.99, 128.64,
128.80, 129.51, 131.95, 132.17, 134.40.135.11, 142.62,
149.75 (phenyl, naphthyl), 165.15, 166.07, 172.05 (triazine).
Anal. (C20H11N5OBrCl) C, H, N, Br, Cl; EIMS m/z: 453 (Mþ).
4.1.2.5. 4-[4-Amino-6-(4-chloro-1-naphthoxy)-1,3,5-triazine-
4.1.2. General procedure for preparation of compounds
8aeg and 9aer
2-yl]aminobenzonitrile (8e). Yield: 0.220 g, 38.4%; m.p.
1
239.8e243.9 ꢀC; H NMR (DMSO-d6) d: 6.48 (s, 2H, NH2),
Amine or NaN3 (0.367, 5.48 mmol) was added to a solution
of 6aeb or 7aee (1.37 mmol) in 1,4-dioxane (150 ml) at room
temperature under stirring, the resulting solution was stirred at
7.28e8.30 (m, 10H, phenyl, naphthyl), 9.41 (s, 1H, NH),
10.02 (s, 1H, NH); 13C NMR (DMSO-d6) d: 104.36 (CN),
118.91, 119.55, 120.06, 122.58, 124.88, 126.48, 127.86,

1234
Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
128.16, 128.61, 128.78, 131.07, 133.37, 145.97, 147.82 (phe-
nyl, naphthyl), 165.71, 167.01, 172.00 (triazine). Anal.
(C20H13ClN6O) C, H, N, Cl; EIMS m/z: 388 (Mþ).
133.20, 133.49, 144.53, 148.83 (phenyl, naphthyl), 165.34,
166.73, 170.24 (triazine). Anal. (C22H16Br2N6O) C, H, N,
Br; EIMS m/z: 540 (Mþ).
4.1.2.6. 4-[4-Ethylamino-6-(4-chloro-1-naphthoxy)-1,3,5-tri-
4.1.2.11. 4-[4-n-Propylamino-6-(1,6-dibromo-2-naphthoxy)-
1,3,5-triazine-2-yl]aminobenzonitrile (9d). Yield: 0.287 g,
37.8%; m.p. 193.0e196.0 ꢀC; 1H NMR (DMSO-d6,
400 MHz) d: 0.86 (t, J ¼ 7.6 Hz, 3H, CH3), 1.53 (m, 2H,
CH2CH3), 3.26 (m, 2H, NHCH2), 7.45e7.76 (m, 4H, phenyl),
7.71e8.48 (m, 5H, naphthyl), 9.92 (s, 1H, NHCH2), 10.07 (s,
1H, NH); 13C NMR (DMSO-d6) d: 11.53 (CH3), 22.5
(CH2CH3), 42.9 (NHCH2), 104.32 (CN) 115.43, 118.00,
119.3, 120.23, 124.86, 128.22, 128.62, 131.07, 131.55,
131.87, 133.56, 133.80, 144.23, 148.35 (phenyl, naphthyl)
165.67, 167.45, 170.34 (triazine). Anal. (C23H18Br2N6O) C,
H, N, Br; EIMS m/z: 554 (Mþ).
azine-2-yl]aminobenzonitrile (8f). Yield: 0.234 g, 39.2%; m.p.
1
289.5e290.8 ꢀC; H NMR (DMSO-d6) d: 1.06 (t, J ¼ 6.8 Hz,
3H, CH3), 3.22 (q, 2H, CH2), 7.32e7.69 (m, 4H, phenyl),
7.71e8.34 (m, 6H, naphthyl), 9.83 (s, 1H, NHCH2), 10.10 (s,
1H, NH); 13C NMR (DMSO-d6) d: 14.87 (CH3), 35.48 (CH2) d:
103.84 (CN), 119.51, 119.80, 122.57, 125.02, 126.71, 127.93,
128.06, 128.54, 131.07, 131.19, 131.44, 132.45, 144.64, 147.69
(phenyl, naphthyl), 165.71, 168.82, 171.24 (triazine). Anal.
(C22H17ClN6O) C, H, N, Cl; EIMS m/z: 417 (Mþ).
4.1.2.7. 4-[4-n-Propylamino-6-(4-chloro-1-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (8g). Yield: 0.217 g, 36.7%;
m.p. 293.5e293.6.0 ꢀC; 1H NMR (DMSO-d6) d: 0.90
4.1.2.12. 4-[4-i-Propylamino-6-(1,6-dibromo-2-naphthoxy)-
3
(t, J ¼ 7.6 Hz, 3H, CH3), 1.56 (m, 2H, CH2CH2CH3), 3.35
1,3,5-triazine-2-yl]aminobenzonitrile (9e). Yield: 0.289 g,
1
(m, 2H, NHCH2), 7.26e7.53 (m, 4H, phenyl), 7.72e8.31
(m, 6H, naphthyl), 9.97 (s, 1H, NH); 13C NMR (DMSO-d6,
400 MHz) d: 11.4 (CH3), 22.23 (CH2CH2CH3), 42.8
(NHCH2CH2CH3), 104.00 (CN), 119.27, 119.77, 120.22,
122.38, 124.30, 126.93, 127.65, 127.89, 128.89, 131.06,
131.06, 132.93, 144.42, 147.78 (phenyl, naphthyl) 165.75,
167.67, 171.45 (triazine). Anal. (C23H19ClN6O) C, H, N, Cl;
EIMS m/z: 430 (Mþ).
38.1%; m.p. 212.4e213.4 ꢀC; H NMR (DMSO-d6) d: 1.22
(dd, J ¼ 6.4 Hz, 6H, CH3), 4.17 (m, 1H, CH), 7.53e8.5 (m,
9H, phenyl, naphthyl), 9.99 (s, 1H, NHCH (CH3)2), 10.10 (s,
1H, NH); 13C NMR (DMSO-d6) d: 22.50 (CH3), 43.27 (CH),
104.42 (CN), 114.80, 119.66, 119.83, 120.34, 125.17, 128.77,
128.83, 130.68, 131.33, 131.60, 133.15, 133.50, 143.87,
148.95 (phenyl, naphthyl), 165.36, 166.83, 170.51 (triazine).
Anal. (C23H18Br2N6O) C, H, N, Br; EIMS m/z: 554 (Mþ).
4.1.2.8. 4-[4-Methylamino-6-(2-naphthoxy)-1,3,5-triazine-2-
yl]aminobenzonitrile (9a). Yield: 0.191 g, 37.9%; m.p.
275.6 ꢀC (dec); 1H NMR (DMSO-d6) d: 2.8 (dd,
3J ¼ 4.4 Hz, 3H, CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e
8.18 (m, 7H, naphthyl), 9.92 (s, 1H, NHCH3), 10.07 (s, 1H,
NH); 13C NMR (DMSO-d6) d: 30.12 (CH3), 104.62 (CN),
121.67, 122.34, 124.23, 127.27, 128.45, 129.12, 130.78,
132.57, 133.04, 134.47, 135.21, 137.67, 147.45, 151.59 (phe-
nyl, naphthyl), 168.45, 170.56, 173.45 (triazine). Anal.
(C21H16N6O) C, H, N; EIMS m/z: 368 (Mþ).
4.1.2.13. 4-[4-i-Propylamino-6-(6-bromo-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9f). Yield: 0.294 g, 38.7%;
m.p. 287.00 ꢀC (dec); 1H NMR (DMSO-d6, 400 MHz) d: 1.17
(dd, J ¼ 6.4 Hz, 6H, CH3), 4.11 (m, 1H, CH), 7.50e8.23 (m,
10H, phenyl, naphthyl), 9.95 (s, 1H, NHCH (CH3)2), 10.12 (s,
1H, NH); 13C NMR (DMSO-d6) d: 27.62 (CH3), 47.34 (CH),
108.7 (CN), 119.78, 124.53, 124.66, 125.27, 128.01, 131.06,
131.36, 133.19, 134.10, 134.42, 137.46, 138.37, 149.20,
153.61 (phenyl, naphthyl), 170.21, 171.45, 175.61 (triazine).
Anal. (C23H18Br2N6O) C, H, N, Br; EIMS m/z: 475 (Mþ).
4.1.2.9. 4-[4-Amino-6-(2-naphthoxy)-1,3,5-triazine-2-yl]ami-
nobenzonitrile (9b). Yield: 0.192 g, 39.6%; m.p. 226.8e
227.9.0 ꢀC; 1H NMR (DMSO-d6) d: 2.49 (s, 2H, NH2),
7.25e7.42 (m, 4H, phenyl), 7.49e8.01 (m, 7H, naphthyl),
10.02 (s, 1H, NH); 13C NMR (DMSO-d6) d: 104.05 (CN),
118.80, 119.38, 120.93, 122.81, 125.23, 126.70, 127.83,
128.08, 129.85, 131.63, 132.92, 133.84, 144.90, 150.76 (phe-
nyl, naphthyl), 165.81, 168.12, 171.24 (triazine). Anal.
(C20H14N6O) C, H, N; EIMS m/z: 354 (Mþ).
4.1.2.14. 4-[4-Methylamino-6-(6-bromo-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9g). Yield: 0.258 g, 39.7%;
1
m.p. 250.1e252.0 ꢀC (dec); H NMR (DMSO-d6) d: 2.8 (dd,
3J ¼ 4.8 Hz, CH3), 7.45e8.27 (m, 10H, phenyl, naphthyl),
9.92 (s, 1H, NHCH3), 10.15 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 27.59 (CH3), 103.92 (CN) 118.81, 119.72,
120.21, 120.73, 123.63, 128.92, 129.86, 132.45, 132.71,
133.01, 133.19, 133.45, 144.73, 151.20 (phenyl, naphthyl),
165.32, 167.45, 171.45 (triazine). Anal. (C21H15BrN6O) C,
H, N, Br; EIMS m/z: 447 (Mþ).
4.1.2.10. 4-[4-Ethylamino-6-(1,6-dibromo-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9c). Yield: 0.311 g, 42.1%;
4.1.2.15. 4-[4-Methylamino-6-(1-bromo-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9h). Yield: 0.231 g, 37.8%;
m.p. 282.4e282.8 ꢀC; 1H NMR (DMSO-d6) d: 2.8 (dd,
3J ¼ 4.4 Hz, 3H, CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e
8.18 (m, 6H, naphthyl), 9.92 (s, 1H, NHCH3), 10.13 (s, 1H,
NH); 13C NMR (DMSO-d6) d: 32.30 (CH3), 108.71 (CN),
119.50, 120.00, 121.34, 123.05, 124.31, 128.42, 131.29,
1
m.p. 225.4e228.0 ꢀC (dec); H NMR (DMSO-d6) d: 1.05 (t,
J ¼ 6.4 Hz, 3H, CH3), 3.23 (q, 2H, CH2), 7.32e7.69 (m, 4H,
phenyl), 7.71e8.35 (m, 5H, naphthyl), 10.01 (s, 1H,
NHCH2), 10.10 (s, 1H, NH); 13C NMR (DMSO-d6) d: 14.40
(CH3), 35.57 (CH2), 104.23 (CN), 114.96, 119.73, 119.86,
120.23, 124.76, 128.73, 129.00, 130.65, 131.01, 131.72,

Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
1235
133.46, 134.67, 135.45, 137.80, 138.34, 149.30, 153.62 (phe-
nyl, naphthyl) 170.69, 172.54, 175.48 (triazine). Anal.
(C21H15BrN6O) C, H, N, Br; EIMS m/z: 447 (Mþ).
129.80, 130.32, 131.11, 131.61, 132.80, 133.40, 144.27,
148.64 (phenyl, naphthyl), 165.85, 167.44, 169.30 (triazine).
Anal. (C21H14Br2N6O) C, H, N, Br; EIMS m/z: 526 (Mþ).
4.1.2.16. 4-[4-Amino-6-(1-bromo-2-naphthoxy)-1,3,5-triazine-
4.1.2.21. 4-[4-Amino-6-(1,6-dibromo-2-naphthoxy)-1,3,5-tri-
2-yl]aminobenzonitrile (9i). Yield: 0.233 g, 39.2%; m.p.
azine-2-yl]aminobenzonitrile (9n). Yield: 0.199 g, 39.5%; m.p.
1
1
210 ꢀC (dec); H NMR (DMSO-d6, 400 MHz) d: 2.78 (s, 2H,
281.3e285.0 ꢀC; H NMR (DMSO-d6) d: 2.04 (s, 2H, NH2),
NH2), 7.57e7.64 (m, 4H, phenyl), 7.66e8.24 (m, 6H, naph-
thyl), 10.00 (s, 1H, NH); 13C NMR (DMSO-d6) d: 103.71
(CN), 114.85, 119.20, 119.82, 123.45, 123.75, 126.32, 126.97,
128.31, 128.84, 129.65, 132.67, 133.46, 145.04, 148.01 (phenyl,
naphthyl), 165.81, 168.82, 170.74 (triazine). Anal.
(C20H13BrN6O) C, H, N, Br; EIMS m/z: 433 (Mþ).
7.53e7.97 (m, 4H, phenyl), 8.01e85 (m, 5H, naphthyl), 10.07
(s, 1H, NH); 13C NMR (DMSO-d6) d: 104.32 (CN), 115.70,
119.71, 119.89, 120.30, 124.87, 128.61, 129.90, 130.52, 131.41,
131.81, 132.40, 133.60, 144.65, 148.00 (phenyl, naphthyl),
165.81, 167.82, 171.24 (triazine). Anal. (C20H12Br2N6O) C, H,
Br, N; EIMS m/z: 512 (Mþ).
4.1.2.17. 4-[4-n-Propylamino-6-(1-bromo-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9j). Yield: 0.254 g, 39.1%;
m.p. 259.5e263.2 ꢀC; 1H NMR (DMSO-d6) d: 0.79 (t,
J ¼ 7.6 Hz, 3H, CH3), 1.47 (d, 2H, CH2CH2CH3), 3.14 (m, 2H,
CH2CH2CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e8.18 (m, 6H,
naphthyl), 9.92 (s, 1H, NHCH3), 10.07 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 11.63 (CH3), 22.43 (CH2CH2CH3), 42.7
(NHCH2), 103.81 (CN), 114.72, 119.30, 119.82, 123.54, 126.52,
126.96, 128.43, 128.73, 129.36, 129.83, 132.45, 133.31, 144.89,
148.49 (phenyl, naphthyl), 165.11, 167.34, 170.89 (triazine).
Anal. (C23H19BrN6O) C, H, N, Br; EIMS m/z: 475 (Mþ).
4.1.2.22. 4-[4-Methylamino-6-(1-chloro-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9o). Yield: 0.212 g, 38.5%;
m.p. 294.4e296.6 ꢀC; 1H NMR (DMSO-d6) d: 2.8 (dd,
3J ¼ 3.6 Hz, 3H, CH3), 7.37e7.66 (m, 4H, phenyl), 7.71e
8.18 (m, 6H, naphthyl), 9.92 (s, 1H, NHCH3), 10.07 (s, 1H,
NH); 13C NMR (DMSO-d6) d: 27.1 (CH3), 103.62 (CN),
119.68, 119.85, 120.08, 122.33, 122.80, 123.51, 123.90,
126.93, 128.52, 128.92, 131.20, 133.35, 144.77, 146.60 (phe-
nyl, naphthyl), 166.10, 167.62, 170.06 (triazine). Anal.
(C21H15ClN6O) C, H, Cl, N; EIMS m/z: 402 (Mþ).
4.1.2.23. 4-[4-Amino-6-(1-chloro-2-naphthoxy)-1,3,5-triazine-
4.1.2.18. 4-[4-Ethylamino-6-(1-chloro-2-naphthoxy)-1,3,5-tri-
azine-2-yl]aminobenzonitrile (9k). Yield: 0.214 g, 37.5%;
m.p. 216.0e218.0 ꢀC; 1H NMR (DMSO-d6) d: 1.07 (t,
J ¼ 7.6 Hz, 3H, CH3), 3.18 (q, 2H, CH2), 7.32e7.69 (m, 4H, phe-
nyl), 7.71e8.35 (m, 6H, naphthyl), 9.86 (s, 1H, NHCH2), 10.14
(s, 1H, NH); 13C NMR (DMSO-d6) d: 15.02 (CH3), 36.34
(CH2), 104.05 (CN), 119.43, 119.60, 122.10, 122.43, 123.56,
123.80, 126.83, 128.25, 131.46, 132.05, 133.57, 144.72,
145.81, 147.00 (phenyl, naphthyl), 166.02, 167.34, 170.53
(triazine). Anal. (C22H17ClN6O) C, H, N, Cl; EIMS m/z:
417 (Mþ).
2-yl]aminobenzonitrile (9p). Yield: 0.218 g, 38.1%; m.p. 188.3e
1
190.1 ꢀC; H NMR (DMSO-d6) d: 4.84 (s, 2H, NH2), 7.24e7.73
(m, 4H, phenyl), 7.80e8.16 (m, 6H, naphthyl), 10.19 (s, 1H, NH);
13C NMR (DMSO-d6) d: 104.33 (CN), 119.88, 119.75, 120.18,
122.53, 122.60, 123.71, 123.98, 126.83, 128.82, 129.32, 131.60,
133.65, 144.97, 146.84(phenyl, naphthyl), 165.81, 167.82, 171.24(tri-
azine). Anal. (C20H13ClN6O) C, H, N, Cl; EIMS m/z: 388 (Mþ).
4.1.2.24. 4-[4-Amino-6-(6-bromo-2-naphthoxy)-1,3,5-triazine-
2-yl]aminobenzonitrile (9q). Yield: 0.233 g, 39.3%; m.p.
249.0e250.30 ꢀC; 1H NMR (DMSO-d6) d: 4.84 (s, 2H, NH2),
7.24e7.73 (m, 4H, phenyl), 7.80e8.16 (m, 6H, naphthyl),
10.19 (s, 1H, NH); 13C NMR (DMSO-d6) d: 103.98 (CN),
118.95, 119.72, 119.98, 120.44, 120.82, 123.76, 124.89,
129.95, 130.09, 133.11, 133.50, 133.91, 144.33, 151.28 (phenyl,
naphthyl), 165.61, 168.92, 171.11 (triazine). Anal.
(C20H13BrN6O) C, H, N, Br; EIMS m/z: 433 (Mþ).
4.1.2.19. 4-[4-n-Propylamino-6-(1-chloro-2-naphthoxy)-1,3,5-
triazine-2-yl]aminobenzonitrile (9l). Yield: 0.162 g, 32.1%;
m.p. 210.0 ꢀC (dec); 1H NMR (DMSO-d6) d: 0.88 (t,
J ¼ 7.2 Hz, 3H, CH3), 1.53 (m, 2H, CH2CH2CH3), 3.30 (m, 2H,
CH2CH2CH3), 7.51e7.66 (m, 4H, phenyl), 7.71e8.18 (m, 6H,
naphthyl), 9.99 (s, 1H, NHCH3), 10.15 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 11.46 (CH3), 22.30 (CH2CH3), 42.63 (NHCH2),
104.34 (CN), 119.35, 120.13, 122.43, 123.46, 126.86, 128.05,
130.65, 131.56, 132.47, 133.05, 135.78, 138.75, 144.74, 146.43
(phenyl, naphthyl), 165.43, 167.56, 170.83 (triazine). Anal.
(C23H19ClN6O) C, H, N, Cl; EIMS m/z: 430 (Mþ).
4.1.2.25. 4-[4-Azido-6-(1-chloro-2-naphthoxy)-1,3,5-triazine-
2-yl]aminobenzonitrile (9r). Yield: 0.197 g, 34.6%; m.p.
192.2e194.1 ꢀC; 13C NMR (DMSO-d6) d: 103.62 (CN),
119.58, 119.75, 120.18, 122.43, 122.90, 123.71, 123.97,
126.99, 128.92, 128.90, 131.60, 133.65, 144.99, 146.70
(phenyl, naphthyl), 166.30, 167.82, 170.26 (triazine). Anal.
(C20H11ClN8O) C, H, N, Cl; EIMS m/z: 415.
4.1.2.20.
4-[4-Methylamino-6-(1,6-dibromo-2-naphthoxy)-
1,3,5-triazine-2-yl]aminobenzonitrile (9m). Yield: 0.262 g,
36.4%; m.p. 293.6e295.0 ꢀC; 1H NMR (DMSO-d6) d: 2.8
(dd, 3J ¼ 4.0 Hz, 3H, CH3), 7.37e7.66 (m, 4H, phenyl),
7.71e8.18 (m, 5H, naphthyl), 9.92 (s, 1H, NHCH3), 10.07
(s, 1H, NH); 13C NMR (DMSO-d6) d: 27.83 (CH3), 104.25
(CN), 115.30, 119.71, 119.85, 120.00, 124.83, 128.41,
4.2. Biological activity
The anti-HIV activity and cytotoxicity were evaluated
against wild-type HIV-1 strain IIIB in MT-4 cells using the
3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide

1236
Y.-Z. Xiong et al. / European Journal of Medicinal Chemistry 43 (2008) 1230e1236
(MTT) method. Briefly, virus stocks were titrated in MT-4
cells and expressed as the 50% cell culture infective dose
(CCID50). MT-4 cells were suspended in culture medium at
1 ꢄ 105 cells/ml and infected with HIV at a multiplicity of in-
fection of 0.02. Immediately after viral infection, 100 ml of the
cell suspension was placed in each well of a flat-bottomed mi-
crotiter tray containing various concentrations of the test com-
pounds. The test compounds were dissolved in DMSO at
50 mM or higher. After 4 days of incubation at 37 ꢀC, the
number of viable cells was determined using the MTT method.
Compounds were tested in parallel for cytotoxic effects in un-
infected MT-4 cells.
References
[1] Y.P. Wang, F.E. Chen, J. Balzarini, E. De Clercq, C. Pannecouque. Chem.
Biodiver., in press. [Reg. No. C07180].
[2] K. Das, A.D. Clark Jr., P.J. Lewi, J. Heeres, M.R. de Jonge,
L.M.H. Koymans, H.M. Vinkers, F. Daeyaert, D.W. Ludovici, M.J. Kukla,
B.D. Corte, R.W. Kavash, C.Y. Ho, H. Ye, M.A. Lichtenstein, K. Andries,
´
R. Pauwels, M.P.D. Bethune, P.L. Boyer, P. Clark, S.H. Hughes,
P.A.J. Janssen, E. Arnold, J. Med. Chem. 47 (2004) 2550e2560.
[3] D.W. Ludovici, M.J. Kukla, P.G. Grous, S. Krishnan, K. Andries, M.P. de
´
Bethune, H. Azijn, R. Pauwels, E. De Clercq, E. Arnold, P.A.J. Janssen,
Bioorg. Med. Chem. Lett. 11 (2001) 2225e2228.
[4] Y.Z. Xiong, F.E. Chen, X.Q. Feng, Acta Chimi. Sin. 64 (2006) 1627e1630.
[5] D.W. Ludovicia, R.W. Kavash, M.J. Kukla, C.Y. Ho, H. Ye, B.L. De Corte,
K. Andries, M.P. de Bethune, H. Azijn, R. Pauwels, H.E.L. Moereels, J. Heeres,
L.M.H. Koymans, M.R. de Jonge, K.J.A. Van Aken, F.F.D. Daeyaert, P.J. Lewi,
K. Das, E. Arnolde, P.A.J. Janssen, Bioorg. Med. Chem. Lett. 11 (2001) 2229e2234.
[6] A. Anu, S. Kumkum, S.K. Puri, M.S. Prem, Bioorg. Med. Chem. Lett. 15
(2005) 531e533.
Acknowledgement
Financial support of this work by the National Science Foun-
dation of China (No. 30672536) is greatly acknowledgement.
[7] R. Pauwels, J. Balzarini, M. Baba, R. Snoeck, E. De Clercq, J. Virol.
Methods 20 (1988) 309e322.