Ultrasound-assisted one-pot synthesis of anti-CML nucleosides featuring 1,2,3-triazole nucleobase under iron-copper catalysis

Article abstract of DOI:10.1016/j.ultsonch.2012.04.007

A simple and efficient synthesis of modified 1,2,3-triazole nucleosides was developed. The strategy involved sequential one-pot acetylation-azidation- cycloaddition procedure and was found to be highly effective under a cooperative effect of ultrasound activation and iron/copper catalysis. The reactions were carried out under both conventional and ultrasonic irradiation conditions. In general, improvement in rates and yields were observed when reactions were carried out under sonication compared with conventional conditions. This one-pot procedure provides several advantages such as operational simplicity, high yield, safety and environment friendly protocol. The resulting substituted nucleosides were evaluated for their anticancer activity against K562 chronic myelogenous leukemia (CML) cell line.

Full text of DOI:10.1016/j.ultsonch.2012.04.007

Ultrasonics Sonochemistry 19 (2012) 1132–1138
Contents lists available at SciVerse ScienceDirect
Ultrasonics Sonochemistry
journal homepage: www.elsevier.com/locate/ultson
Short Communication
Ultrasound-assisted one-pot synthesis of anti-CML nucleosides featuring
1,2,3-triazole nucleobase under iron-copper catalysis
Mohsine Driowya a,b, Alexandre Puissant c, Guillaume Robert c, Patrick Auberger c, Rachid Benhida a,
,
⇑
Khalid Bougrin b,
⇑
a Institut de Chimie de Nice UMR CNRS 7272, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France
b Laboratoire de Chimie des Plantes et de Synthèse Organique et Bioorganique, URAC23, Université Mohammed V-Agdal, Faculté des Sciences B.P. 1014 Rabat, Morroco
c Centre Méditérranéen de Médecine Moléculaire UMR INSERM U1065, Equipe 2 Cell Death Differentiation and Cancer, Equipe Labellisée par la Ligue Nationale contre le Cancer,
Université de Nice-Sophia Antipolis, C3M - Bâtiment ARCHIMED 151 route Saint Antoine de Ginestière, 06204 Nice, France
a r t i c l e i n f o
a b s t r a c t
Article history:
A simple and efficient synthesis of modified 1,2,3-triazole nucleosides was developed. The strategy
involved sequential one-pot acetylation-azidation-cycloaddition procedure and was found to be highly
effective under a cooperative effect of ultrasound activation and iron/copper catalysis. The reactions were
carried out under both conventional and ultrasonic irradiation conditions. In general, improvement in
rates and yields were observed when reactions were carried out under sonication compared with conven-
tional conditions. This one-pot procedure provides several advantages such as operational simplicity,
high yield, safety and environment friendly protocol. The resulting substituted nucleosides were evalu-
ated for their anticancer activity against K562 chronic myelogenous leukemia (CML) cell line
Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved.
Received 8 February 2012
Received in revised form 29 March 2012
Accepted 8 April 2012
Available online 25 April 2012
Keywords:
Click
Ultrasound activation
Iron-copper catalysis
Bioactive nucleosides
CML
1. Introduction
treatment of chronic myelogenous leukemia (CML) in accelerated
phase or blast crisis, despite of its high toxicity.
Naturally occurring and synthetic analogs of nucleosides have
been the cornerstone of antiviral therapy over the last decades.
The growing interest in such analogs also rises from their high
potential value as therapeutic agents, biochemical probes and as
building blocks in the synthesis of artificial DNA and RNA [1].
Among them, nucleosides with five membered ring nucleobase
are of great interest. For example, Ribavirin (Fig. 1) is a synthetic
nucleoside endowed with a broad-spectrum of antiviral activity
against many RNA and DNA viruses. It is the unique small molecule
drug currently used for the treatment of hepatitis C virus [2]. AICAR
is a natural metabolite involved in the in vivo adenine and guanine
nucleotide pool synthesis. It is a potent AMP-activated protein
kinase activator used for the treatment of acute lymphoblastic
leukemia and other diseases such as diabetes, cardiovascular and
cerebrovascular complications and other metabolic disorders [3].
Pyrazomycin, pyrazole-containing structure, is an antibiotic pro-
duced by fermentation of Streptomyces candidus NRRL 3601
(Fig. 1) [4]. Tiazofurin is a well-known C-nucleoside with interest-
ing anticancer and antiviral activities [5]. Recently, the FDA
granted orphan-drug status designation to tiazofurin for the
Among the five-membred nucleosides, triazole analogs are also
of great interest since they exhibit a wide range of biological activ-
ities and several methodologies were developed for the synthesis
of this class of analogs [6]. Huisgen azide–alkyne 1,3-dipolar cyclo-
addition is a versatile route to 1,2,3-triazoles, and the progress in
this area has been extensively studied [7]. In general, 1,2,3-triazole
formation requires harsh conditions and this cycloaddition reac-
tion usually leads to a mixture of 1,4- and 1,5-regioisomers [8].
In 2002, K. B. Sharpless and M. Meldal improved the regioselectiv-
ity of the cycloaddition by Cu(I)-catalyzed ligation (click chemis-
try) of organic azides and terminal alkynes [9]. Recently, several
examples of Cu(I)-catalyzed alkyne–azide 1,3-dipolar cycloaddi-
tion under mild conditions have been described [10].
Ultrasound activation has emerged as a powerful technique to
enhance reaction rates of a variety of chemical transformations
[11]. Moreover, ultrasound reactions using green catalysts such
as iron and copper are attractive in the growing field of green
and more sustainable chemistry [12]. Only few examples of
azide-alkyne 1,3-dipolar cycloaddition were reported under ultra-
sound activation [13]. In our knowledge, the ultrasound-assisted
synthesis of triazolyl-nucleosides has not yet been reported [14].
In continuation of our investigations for the development of ori-
ginal routes to bioactive nucleosides [15], we report herein the first
example of one-pot regioselective synthesis of functionalized
⇑
Corresponding authors.
E-mail address: benhida@unice.fr (R. Benhida).
1350-4177/$ - see front matter Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.ultsonch.2012.04.007

M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
1133
2. Results and discussions
As a model reaction, we investigated the reactivity of glucose 1a
and Ac2O in the presence of various catalysts under solvent-free
conditions, in the presence and absence of ultrasound irradiation,
respectively (Table 1). First, acetylation using copper catalysts un-
der magnetical stirring produced the desired product 2a in low
yields (entries 1 and 2). Although the yields were low, this result
clearly showed the ultrasound effect since they were increased
from 43% and 21% to 68% and 40%, respectively. CoCl2, NiCl2 and
NiSO4 were found to be less effective and did not significantly
change the results (entries 3–5). Interestingly, BF3Et2O, ZnCl2 and
SnCl2 gave high yields and reactions were significantly accelerated
under ultrasound irradiation (entries 6–8). The best result was ob-
tained using FeCl3 as a catalyst leading to 2a in near quantitative
yield and within a short reaction time, compared to conventional
conditions (table 1, entry 10). FeCl2 also led to 93% yield (entry
9) while, other iron catalysts such as Fe(acac)3 and Fe(NO3)3 were
not effective for this transformation (data not shown).
Fig. 1. Example of bioactive five-membered ring nucleosides.
In the second azidation step, we selected the best catalysts as
depicted in Table 2. We found that, in all cases, the reactions were
accelerated under ultrasound irradiation. Interestingly, while the
yields in the presence of BF3Et2O, ZnCl2, SnCl2 did not change be-
tween conventional and ultrasound activation, the reaction yields
with iron catalysts were significantly increased after only 15 min
of ultrasonication, compared to 3 h under conventional conditions
(entries 4 and 5). This result demonstrates that the high-energy ef-
fects of acoustic cavitation with the expected mechanical pulveri-
zation and ultimate dissolution of suspended iron catalysts were
responsible for the enhanced reaction rate and yield.
Scheme 1. The proposed sequential one-pot process.
Table 1
The effect of catalysts and ultrasound in the acetylation reaction.
The 1,3-dipolar cycloaddition step was carried out using the azi-
do-sugar 3a and the thienyl-acetylene as a model reaction. After
optimization of the reaction conditions, the best results were ob-
tained using alkyne/CuI/DIEA in 1.8/2/2 M ratio. Under these con-
ditions, the cycloadduct 4a was obtained in high yield under
ultrasonication (94%, 20 min) compared to conventional activation
(58% after 2 h, Scheme 2). Furthermore, the use of small amount of
catalyst (CuI, 0.2 equiv) only gave low yields even under Sharpless
conditions that involved Cu(II) catalyst and sodium ascorbate as a
reducing agent (scheme 2) [9].
Considering the efficiency of the procedure described above
with iron and copper catalysts, the scope of these transformations
was examined with a range of sugars and alkynes under ultrasound
activation (Table 3). Furthermore, to avoid storage and manipula-
tion of organic azide known for their low stability a one-pot pro-
cess was explored.
Entrya
Catalystb
Time
Yield (%)c
Stirring (h)
))) (min)
Stirring (h)
))) (min)
1
2
3
4
5
6
7
8
9
10
CuCl2
Cu(OAc)2
CoCl2
24
48
48
24
24
2
1.5
1.5
2
30
45
60
45
45
15
15
20
15
12
43
21
17
25
26
92
94
87
91
93
68
40
29
38
38
94
92
86
93
97
NiCl2
NiSO4
BF3OMe2
ZnCl2
SnCl2
FeCl2
FeCl3
2
a
b
c
Ac2O (5.5 equiv.).
catalyst (10 mol%).
Pure isolated product (bath kept at rt).
))): under ultrasound irradiation.
As shown in the table 3, all experiments were performed in rel-
atively short global times (50–190 min) and in good overall yields
(three steps, 58–86%). However, some cycloaddition reactions re-
quired a mild heating at 35 °C due to the poor reactivity of the dipol-
arophiles used. For example, dipolarophiles with electron-donating
groups, such as alkyl- and aryl-substituted alkynes (entries 8, 9, 11,
1,2,3-triazolyl nucleosides through a sequential acetylation-azida-
tion followed by 1,3-dipolar cycloaddition between azido-sugars
and various terminal alkynes (Scheme 1), by using a cooperative
effect of iron/copper catalysis and ultrasound activation. The ob-
tained nucleosides were then evaluated for their anti-CML activity
using the well characterized K562 cell line.
Table 2
The effect of catalysts and ultrasound in the azidation reaction.
a
Entry
Catalystb
Time
Yield (%)c
Stirring (h)
))) (min)
Stirring (h)
))) (min)
1
2
3
4
5
BF3OMe2
ZnCl2
SnCl2
FeCl2
FeCl3
2
3
3
3
3
20
25
25
15
15
85
73
70
71
74
84
75
72
85
90
a
b
c
TMSN3 (1.8 equiv.), CH2Cl2.
catalyst (10 mol%).
Pure isolated product (bath kept at rt).
))): under ultrasound irradiation.

1134
M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
Scheme 2. A model reaction for the 1,3-dipolar cycloaddition.
Table 3
Generalization of the one-pot three-step procedure under ultrasound irradiation.
a
Entry
1
Alkyne / sugarb
Product
Time (min)
100
Yield (%)c
86
2
3
80
55
77
85
4
5
6
7
90
83
74
86
70
75
50
120
8d
90
67
70
84
58
80
62
9d
190
90
10
11d
12
13d
150
60
120

M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
1135
Table 3 (continued)
a
Entry
Alkyne / sugarb
Product
Time (min)
120
Yield (%)c
14d
67
15e
75
78
a
All reaction steps were monitored by TLC analysis, Ac2O (5.5 equiv.), FeCl3 (10 mol%), TMSN3 (1.8 equiv.), Alkyne/CuI/DIPEA (1.8:2:2).
sugar = glucose, ribose, 2-deoxyribose or 1-methoxy-2-deoxyribose.
Pure isolated product.
b
c
d
e
heating at 35 °C.
a/b (60/40).
))): under ultrasound irradiation.
Fig. 2. Significant NOESY and HMBC correlations.
original mode of action [16]. Cell Metabolism was measured by
XTT assay using sodium 30-[1-(phenylaminocarbonyl)-3,4-tetrazo-
lium]-bis(4-methoxy-6-nitro)-benzene-sulfonic acid hydrate for
UV–visible monitoring. Absorbance of the formazan dye produced
by metabolically active cells was measured at 490 nm as described
earlier [16]. Among all compound tested, derivatives 4i (methoxy-
naphthyl) and 4j (pyridyl) were found to be the most active in
K562 CML cells. They showed appropriate decrease of cell viability
and promising therapeutic potential in CML compared to AICAR
(Table 4). Indeed, these compounds kill 77–93% of CML cancer cells
at 0.5 mM concentration compare to AICAR (35%). We also
observed that compounds featuring ribose sugar, close analogs of
AICAR, are more active than those with glucose or 2-deoxyribose.
It is worth noting that the substituent on triazole ring has also a
dramatic effect on CML activity since compounds featuring meth-
oxynaphthyl and pyridyl exhibit high activity and are two to three
fold more active than AICAR, whereas triazolyl-nucleosides with
aromatic (thienyl, phenyl, and methoxyphenyl) or alkyl substitu-
ents have only low activity.
Table 4
Cell viability, CML K562 cell line (% inhibition at 0.5 mM, XTT assays).
a
a
Entry
Compound
% Inhibition
Entry
Compound
% Inhibition
1
2
3
4
5
6
7
8
4a
4b
4c
4d
4e
4f
5
12
0
8
0
5
13
17
9
4i
4j
4 k
4 l
4 m
4n
93
77
8
20
15
12
22
35
10
11
12
13
14
15
16
4 g
4 h
4o
AICAR
a
Each assay was performed in quadruplicate.
13, 14), decreased the efficiency of the cycloaddition step, and re-
quired a longer reaction time (90–190 min) to achieve better yields
(58–70%). In line with this observation, the best results are obtained
when ethyl propiolate was used as dipolarophile leading to high
overall yields 84–86% (entries 3 and 6) after only 50–55 min of irra-
diation. Indeed, the presence of an electron-withdrawing group in-
creases the efficiency of the dipolar cycloaddition between the
azido-sugar and the activated dipolarophile.
3. Conclusion
Furthermore, no epimerization of the anomeric stereocenter
was observed since the anomeric stereochemistry of all products
remained unchanged during this one-pot three-step process, as at-
tested by 1H NMR and 13C NMR data. For example, the stereo- and
regio-chemistry of 4a and 4d (b configuration and thienyl in posi-
tion 4) was unambiguously attested by NOESY and HMBC experi-
ments. Indeed, the 1H 2D NOESY spectrum of 4a shows
correlations between H10-H30 and H10-H5 triazole. Moreover, the
chemical shift of H10 at 5.90 ppm and its coupling with H20
(J = 9.0 Hz) clearly argue for a b configuration. In the 1H–13C HMBC
experiment we showed C10-H5 and H5–C3 thienyl cross coupling,
in accordance with the proposed structure for 4a (Fig. 2). Similar
results were also obtained with 4d.
In summary we have developed a clean, efficient and rapid pro-
tocol for the synthesis of triazolyl-4-substituted nucleosides. This
new methodology is based on a one-pot procedure that involves
a cooperative effect of iron-copper catalysis and ultrasound activa-
tion starting from available starting materials. Moreover, we found
that some of the synthesized compounds are more active than AI-
CAR to kill CML cancer in K562 cell line. The study of the exact
mode of action of this series of compounds and the elaboration
of more active analogs are under way.
4. Experimental
All the obtained products 4a–4o were evaluated for their poten-
tial antileukemic effect towards the chronic myelogenous leuke-
mia (CML) K562 cell line, which is widely used for cytotoxicity
assays. The effect of compounds 4a–4o was compared with that
of AICAR, a potent inhibitor that kills CML cells according to an
4.1. General
All organic solvents were purchased from commercial sources
and used as received or dried using standard procedures, unless

1136
M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
otherwise stated. All chemicals were purchased from Aldrich,
Merck or Alfa Aesar and used without further purification; thin-
layer chromatography (TLC) was performed on precoated Merck
60 GF254 silica gel plates and revealed by spraying (p-anisalde-
hyde or H2SO4/EtOH), and detection by means of UV light at 254
and 360 nm. 1H and 13C NMR spectra were recorded on a Bruker
Avance 200 MHz spectrometer using CDCl3 as solvent and tetra-
methylsilane (TMS) as the internal standard. Mass spectra (ESI
MS) were recorded on a Brucker (Daltonics Esquire 3000+). The
purity of compounds was further verified to be >95% by HPLC anal-
ysis using analytical columns Hypersil (C18 (ELITE), 4.6 mm ꢀ
250 mm) or Nucleosil (120-5C8 (HICHROM), 4.6 mm ꢀ 250 mm)
with an isocratic elution of CH3CN/H2O, 90/10. The ultrason-as-
sisted reactions were carried out in a 00Branson BransonicÒ 5510
DTH UltraSonic Bath Cleaner00, with a frequency of 40 kHz. The
ultrasonic cleaner had a power consumption of 185 W (399 ꢀ
371 ꢀ 401 mm) with liquid holding capacity of 9.5 L. The reactions
were carried out in a round-bottomed flask of 25 mL capacity sus-
pended at the center of the cleaning bath, 5 cm below the surface
of the liquid. The reaction flask was located in the cleaner, where
the surface of reactants is slightly lower than the level of the water.
The reaction temperature was controlled by addition or removal of
water from ultrasonic bath.
1H, J = 8.7 Hz, H-10), 7.30–7.50 (m, 3H, H-Ar), 7.81 (d, J = 8.3 Hz,
2H, H-Ar), 8.95 (s, 1H, H-triazole); 13C NMR (50 MHz, CDCl3): d
(ppm) = 20.1, 20.3, 20.4, 61.7, 67.5, 70.2, 72.0, 73.2, 83.9, 120.3,
125.2, 128.2, 128.9, 130.0, 146.9, 168.5, 169.3, 169.5, 170.0.
4.2.3. 10-(4-Ethoxycarbonyl-[1,2,3]-triazol-1-yl)-20,30,40,60-tetra-O-
acetyl-b-D-glucopyranose (4c)
Rf = 0.33; MS (ESI+): m/z = 494.2 [M + Na]+, 965.4 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 1.36 (t, 3H, J = 7.1 Hz, CH3), 1.83
(s, 3H, Ac), 1.98 (s, 3H, Ac), 2.02 (s, 3H, Ac), 2.03 (s, 3H, Ac), 3.90–
4.00 (m, 1H, H-50), 4.00–4.30 (m, 2H, 2H-60), 4.38 (q, 2H, J = 7.1 Hz,
CH2 ester), 5.15–5.30 (m, 1H, H-40), 5.35–5.45 (m, 2H, H-20 and H-
30), 5.90–6.00 (m, 1H, H-10), 8.37 (s, 1H, H-triazole); 13C NMR
(50 MHz, CDCl3): d (ppm) = 14.3, 20.1, 20.5, 20.7, 61.5, 61.6, 67.6,
70.5, 72.4, 75.3, 85.9, 126.2, 140.9, 160.2, 169.0, 169.4, 169.9, 170.5
4.2.4. 10-(4-(3-Thienyl)-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4d)
Mp = 96–97 °C (foam), Rf = 0.39; MS (ESI+): m/z = 432.1
[M + Na]+, 841.2 [2 M + Na]+; HRMS (ESI+): calcd for
C
17H19N3O7SH+ 410.10165, found 410.10251; 1H NMR (200 MHz,
CDCl3): d (ppm) = 1.99 (s, 3H, Ac), 2.06 (s, 6H, 2Ac), 4.16 (dd, 1H,
J = 12.2 and 4.2 Hz, H-50), 4.35 (dd, 1H, J = 12.6 and 3.0 Hz, H-50),
4.39–4.47 (m, 1H, H-40), 5.56 (t, 1H, J = 5.3 Hz, H-30), 5.82 (dd, 1H,
J = 5.0 and 3.8 Hz, H-20), 6.12 (d, 1H, J = 3.7 Hz, H-10), 7.29–7.39
(m, 2H, H-Ar), 7.60–7.66 (m, 1H, H-Ar), 7.80 (s, 1H, H-triazole);
13C NMR (50 MHz, CDCl3): d (ppm) = 20.4, 20.5, 20.7, 62.8, 70.7,
74.3, 80.9, 90.0, 118.5, 121.6, 125.7, 126.5, 131.2, 144.3, 169.3,
169.4, 170.4.
4.2. General procedure for the synthesis of compounds 4a-o
0.52 mL (5.5 mmol) of Ac2O were added to a mixture of sugar
1a-c (1 mmol) and FeCl3 (0.1 mmol, 16.2 mg). The reaction mixture
was submitted to ultrasound irradiation at 25 °C for 15 min (the
solution become clear). Then, 1.8 mmol (0.24 mL) of TMSN3 and
5 mL of CH2Cl2 were added with additional irradiation (20 min).
After the end of the azidation (TLC monitoring), alkyne, CuI and
DIEA (1.5/2/2 M) were added successively and the mixture was
sonicated according to the time reported in Table 3. Reactions were
then quenched with aqueous NH4Cl (20 mL) and extracted with
CH2Cl2 (2 ꢀ 20 mL). The organic phase was washed with water
(20 mL) and saturated brine solution (20 mL), dried over MgSO4
and concentrated in vacuum to give the crude product, which
was purified by flash silica gel chromatography (cyclohexane/
EtOAc: 70/30) to afford the pure adducts 4a-o. The Rf was mea-
sured for each compound on silica gel TLC using cyclohexane/
EtOAc (70/30) as eluents
4.2.5. 10-(4-Phenyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4e)
Mp = 78–79 °C (foam), Rf = 0. 34; MS (ESI+): m/z = 426.2
[M + Na]+, 829.3 [2 M + Na]+; HRMS (ESI+): calcd for C19H21N3O7H+
404.14523, found 404.14563 ; 1H NMR (200 MHz, CDCl3):
d
(ppm) = 1.97 (s, 3H, Ac), 2.05 (s, 6H, 2Ac), 4.15 (dd, 1H, J = 12.2
and 4.2 Hz, H-50), 4.33 (dd, 1H, J = 12.3 and 3.2 Hz, H-50), 4.38–
4.46 (m, 1H, H-40), 5.57 (t, 1H, J = 5.3 Hz, H-30), 5.83 (dd, 1H,
J = 5.1 and 3.7 Hz, H-20), 6.12 (d, 1H, J = 3.7 Hz, H-10), 7.26–7.40
(m, 3H, H-Ar), 7.73 (dd, 2H, J = 8.2 and 1.6 Hz, H-Ar), 7.90 (s, 1H,
H-triazole); 13C NMR (50 MHz, CDCl3): d (ppm) = 20.4, 20.5, 20.6,
62.8, 70.7, 74.3, 80.9, 90.0, 118.8, 125.8, 128.5, 128.9, 130.0,
148.1, 169.3, 169.4, 170.3.
4.2.1. 10-(4-(3-Thienyl)-[1,2,3]-triazol-1-yl)-20,30,40,60-tetra-O-acetyl-
b-D-glucopyranose (4a)
4.2.6. 10-(4-Ethoxycarbonyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-
b-D-ribofuranose (4f)
Mp = 209–210 °C, Rf = 0.43; MS (ESI+): m/z = 504.0 [M + Na]+,
985.1 [2 M + Na]+; HRMS (ESI+): calcd for C20H23N3O9SNa+
Rf = 0. 29; MS (ESI+): m/z = 422.2 [M + Na]+, 821.3 [2 M + Na]+;
1H NMR (200 MHz, CDCl3): d (ppm) = 1.34 (t, 3H, J = 7.1 Hz, CH3 es-
ter), 2.05 (s, 3H, Ac), 2.06 (s, 3H, Ac), 2.07 (s, 3H, Ac), 4.19 (dd, 1H,
J = 12.6 and 3.5 Hz, H-50), 4.37 (q, 2H, J = 7.2 Hz, CH2 ester), 4.30–
4.50 (m, 2H, H-40 and H- 50), 5.49 (t, 1H, J = 5.5 Hz, H-30), 5.74
(dd, 1H, J = 5.1 and 3.6 Hz, H 20), 6.16 (d, 1H, J = 3.6 Hz, H-10),
504.10472, found 504.10583; 1H NMR (200 MHz, CDCl3):
d
(ppm) = 1.85 (s, 3H, Ac), 2.00 (s, 3H, Ac), 2.04 (s, 3H, Ac), 2.05 (s,
3H, Ac), 3.98–4.05 (m, 1H, H-50), 4.08 (d, 1H, J = 12.6 Hz, H-60),
4.25 (dd, 1H, J = 12.6 and 4.9 Hz, H-60), 5.23 (t, 1H, J = 9.3 Hz, H-
40), 5.42 (t, 1H, J = 9.3 Hz, H-30), 5.51 (t, 1H, J = 9.3 Hz, H-20), 5.90
(d, 1H, J = 9.0 Hz, H-10), 7.31–7.44 (m, 3H, H-Ar), 7.75 (d,
J = 8.3 Hz, 2H, H-Ar), 8.06 (s, 1H, H-triazole); 13C NMR (50 MHz,
DMSOd6): d (ppm) = 20.1, 20.3, 20.4, 61.7, 67.5, 70.2, 72.0, 73.2,
83.9, 120.3, 125.2, 128.2, 128.9, 130.0, 146.9, 168.5, 169.3, 169.5,
170.0.
8.29 (s, 1H, H-triazole); 13C NMR (50 MHz, CDCl3):
d
(ppm) = 14.3, 20.4, 20.5, 20.8, 61.5, 62.5, 70.3, 74.5, 81.1, 90.5,
126.7, 140.6, 160.4, 169.2, 169.5, 170.3.
4.2.7. 10-(4-Benzyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4g)
4.2.2. 10-(4-Phenyl-[1,2,3]-triazol-1-yl)-20,30,40,60-tetra-O-acetyl-b-D-
glucopyranose (4b)
Rf = 0.33; MS (ESI+): m/z = 440.1 [M + Na]+, 857.3 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 1.86 (s, 3H, Ac), 2.03 (s, 6H, 2Ac),
4.01 (s, 2H, CH2Ph), 4.09 (dd, 1H, J = 12.2 and 4.1 Hz, H-50), 4.30 (dd,
1H, J = 12.4 and 3.0 Hz, H-50), 4.33–4.41 (m, 1H, H-40), 5.51 (t, 1H,
J = 5.3 Hz, H-30), 5.70 (dd, 1H, J = 5.1 and 3.9 Hz, H-20), 6.01 (d,
1H, J = 3.8 Hz, H-10), 7.14–7.25 (m, 5H, H-Ar), 7.28 (s, 1H, H-tria-
zole); 13C NMR (50 MHz, CDCl3): d (ppm) = 20.4, 20.5, 20.7, 34.8,
Mp = 212–213 °C, Rf = 0.40; MS (ESI+): m/z = 498.2 [M + Na]+,
973.5 [2 M + Na]+; HRMS (ESI+): calcd for C22H25N3O9H+
476.16636, found 476.16687; 1H NMR (200 MHz, CDCl3):
d
(ppm) = 1.79 (s, 3H, Ac), 1.96 (s, 3H, Ac), 1.99 (s, 3H, Ac), 2.03 (s,
3H, Ac), 3.98–4.07 (m, 1H, H-50), 4.10–4.21 (m, 2H, 2H-60), 5.17
(t, 1H, J = 9.3 Hz, H-40), 5.55–5.73 (m, 2H, H-30 and H-20), 6.38 (d,

M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
1137
62.6, 70.8, 74.4, 80.9, 90.1, 118.9, 125.8, 128.4, 128.9, 130.0, 148.2,
169.3, 169.4, 170.3.
4.2.13. 10-(4-(1-Hydroxyhexyl)-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-
acetyl-b-D-ribofuranose (4m)
Rf = 0.33; MS (ESI+): m/z = 450.0 [M + Na]+, 877.1 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 0.72–0.90 (m, 3H, CH3), 1.13–
1.38 (m, 6H, (CH2)3), 1.50–1.68 (m, 2H, CH2), 2.01 (s, 3H, Ac),
2.05 (s, 6H, 2Ac), 3.67 (s, 1H, OH), 4.13 (dd, 1H, J = 12.1 and
4.1 Hz, H-50), 4.32 (dd, 1H, J = 12.2 and 2.8 Hz, H-50), 4.37–4.47
(m, 1H, H-40), 4.82 (t, 1H, J = 6.2 Hz, CH aliph), 5.53 (t, 1H,
J = 5.3 Hz, H-30), 5.73 (dd, 1H, J = 5.1 and 3.7 Hz, H-20), 6.08 (d,
1H, J = 2.9 Hz, H-10), 7.63 (s, 1H, H-triazole); 13C NMR (50 MHz,
CDCl3): d (ppm) = 14.0, 20.4, 20.5, 20.7, 22.5, 30.1, 31.6, 37.2,
62.8, 67.0 70.6, 74.3, 80.7, 90.0, 119.7, 152.2, 169.3, 169.4, 170.4.
4.2.8. 10-(4-Phenethyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4h)
Rf = 0. 32; MS (ESI+): m/z = 454.2 [M + Na]+, 885.4 [2 M + Na]+;
1H NMR (200 MHz, CDCl3): d (ppm) = 1.97 (s, 3H, Ac), 2.04 (s, 6H,
2Ac), 2.88–3.03 (m, 4H, CH2CH2Ph), 4.12 (dd, 1H, J = 12.1 and
4.2 Hz, H-50), 4.30 (dd, 1H, J = 12.2 and 3.0 Hz, H-50), 4.34–4.41
(m, 1H, H-40), 5.52 (t, 1H, J = 5.2 Hz, H-30), 5.70 (dd, 1H, J = 5.1
and 3.9 Hz, H-20), 6.02 (d, 1H, J = 3.8 Hz, H-10), 7.07–7.22 (m, 5H,
H-Ar), 7.24 (s, 1H, H-triazole); 13C NMR (50 MHz, CDCl3): d
(ppm) = 20.4, 20.5, 20.7, 30.1, 35.3, 62.9, 70.7, 74.2, 80.7, 89.8,
120.1, 126.2, 128.4, 140.9, 147.7, 169.3, 169.4, 170.3.
4.2.14. 10-(4-Octyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4n)
Mp = 207–208 °C, Rf = 0.38; MS (ESI+): m/z = 462.2 [M + Na]+,
878.5 [2 M + Na]+; HRMS (ESI+): calcd for C21H33N3O7H+
4.2.9. 10-(4-(6-Methoxynapht-2-yl)-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-
acetyl-b-D-ribofuranose (4i)
440.23913, found 440.23969; 1H NMR (200 MHz, CDCl3):
d
Rf = 0.46; MS (ESI+): m/z = 506.1 [M + Na]+, 989.4 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 2.00 (s, 3H, Ac), 2.07 (s, 6H, 2Ac),
3.86 (s, 3H, OCH3), 4.19 (dd, 1H, J = 12.1 and 4.1 Hz, H-50), 4.34 (dd,
1H, J = 11.8 and 3.0 Hz, H-50), 4.42–4.49 (m, 1H, H-40), 5.60 (t, 1H,
J = 5.2 Hz, H-30), 5.87 (dd, 1H, J = 5.1 and 3.7 Hz, H-20), 6.15 (d,
1H, J = 3.7 Hz, H-10), 7.07 (s, 1H, H-Ar), 7.12 (d, 1H, J = 2.5 Hz, H-
Ar), 7.68–7.83 (m, 3H, H-Ar), 7.96 (s, 1H, H-triazole), 8.20 (s, 1H,
H-Ar); 13C NMR (50 MHz, CDCl3): d (ppm) = 20.4, 20.5, 20.7, 55.3,
62.8, 70.7, 74.3, 80.9, 90.1, 105.8, 118.6, 119.4, 124.3, 124.5,
125.2, 127.4, 128.9, 129.7, 134.5, 148.4, 158.0, 169.3, 169.5, 170.4.
(ppm) = 0.74–0.88 (m, 3H, CH3), 1.12–1.40 (m, 10H, (CH2)5),
1.50–1.70 (m, 2H, CH2), 2.00 (s, 3H, Ac), 2.05 (s, 6H, 2Ac), 2.64 (t,
2H, J = 7.5 Hz, CH2), 4.14 (dd, 1H, J = 12.3 and 4.3 Hz, H-50), 4.32
(dd, 1H, J = 12.3 and 3.0 Hz, H-50), 4.37–4.45 (m, 1H, H-40), 5.55
(t, 1H, J = 5.3 Hz, H-30), 5.74 (dd, 1H, J = 5.2 and 3.8 Hz, H-20), 6.05
(d, 1H, J = 3.7 Hz, H-10), 7.40 (s, 1H, H-triazole); 13C NMR
(50 MHz, CDCl3): d (ppm) = 14.1, 20.4, 20.5, 20.7, 22.6, 25.6, 29.1,
29.2, 31.8, 62.9, 70.7, 74.2, 80.6, 89.8, 119.7, 148.9, 169.3, 169.4,
170.3.
4.2.15. 20-Deoxy-10-(4-phenyl-[1,2,3]-triazol-1-yl)-30,50-di-O-acetyl-
D-ribofuranose (4o)
4.2.10. 10-(4-(2-Pyridyl)-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-D-
ribofuranose (4j)
Rf = 0.32; MS (ESI+): m/z = 368.1 [M + Na]+, 713.3 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 1.84 (s, 3H, Ac), 1.98 (s, 3H, Ac),
2.40–3.15 (m, 2H, 2H-20), 3.90–4.50 (m, 3H, H-40 and 2H-50), 5.10–
5.20 (m, 0.6H, H-30a), 5.25–5.38 (m, 0.4H, H-30b), 6.20–6.35 (m, 1H,
H-10), 7.16–7.37 (m, 3H, H-Ar), 7.68–7.75 (m, 2H, H-Ar), 7.92 (s,
Rf = 0.30; MS (ESI+): m/z = 427.0 [M + Na]+, 831.1 [2 M + Na]+; 1H
NMR (200 MHz, CDCl3): d (ppm) = 2.06 (s, 9H, 3Ac), 4.20 (dd, 1H,
J = 12.3 and 3.9 Hz, H-50), 4.35 (dd, 1H, J = 12.4 and 3.0 Hz, H-50),
4.40–4.49 (m, 1H, H-40), 5.57 (t, 1H, J = 5.3 Hz, H-30), 5.81 (dd, 1H,
J = 5.1 and 3.8 Hz, H-20), 6.18 (d, 1H, J = 3.6 Hz, H-10), 7.20 (s, 1H,
H-Ar), 7.73 (t, 1H, J = 7.7 Hz, H-Ar), 8.11 (d, 1H, J = 7.8 Hz, H-Ar),
8.33 (s, 1H, H-triazole), 8,51 (d, 1H, J = 4.1 Hz, H-Ar); 13C NMR
(50 MHz, CDCl3): d (ppm) = 20.4, 20.5, 20.7, 62.7, 70.5, 74.4, 80.8,
90.2, 120.3, 121.2, 123.1, 136.9, 148.8, 149.5, 149.7, 169.2, 169.4,
170.4.
0.4H, H-triazole b), 7.99 (s, 0.6H, H-triazole
a
); 13C NMR
(50 MHz, CDCl3): d (ppm) = 21.1, 21.2, 37.8, 38.3, 63.9, 74.4 74.6,
83.6, 83,9, 89.0, 89.8, 118.5, 119.3, 126.0, 128.5, 128.6, 129.2
130.7, 130.9, 148.1, 148.3, 170.6, 170.7.
Acknowledgements
4.2.11. 10-(4-(4-Methoxyphenyl)-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-
acetyl-b-D-ribofuranose (4k)
This work is supported by ValorPaca and SATT Paca-Corse, AR-
CUS-CERES, MAE, Egide Volubilis, CNRST-Morocco, the Ligue Natio-
nale Contre le Cancer (LNCC Equipe labellisée 2011), the
Association pour la Recherche sur le Cancer (ARC), the Institut na-
tional du cancer INCa-PL2011-0249. GR is the recipient from a fel-
lowship from the Fondation de France (FDF) and MD from Egide-
Eiffel and AUF. The authors would like to acknowledge Jean-Marie
Guigonis and Marc Gaysinski for HRMS and NOESY-HMBC NMR
data, respectively.
Rf = 0. 26; MS (ESI+): m/z = 456.1 [M + Na]+, 889.2 [2 M + Na]+;
1H NMR (200 MHz, CDCl3): d (ppm) = 1.98 (s, 3H, Ac), 2.06 (s, 6H,
2Ac), 3.77 (s, 3H, OCH3), 4.16 (dd, 1H, J = 12.1 and 4.1 Hz, H-50),
4.34 (dd, 1H, J = 12.0 and 3.0 Hz, H-50), 4.39–4.47 (m, 1H, H-40),
5.58 (t, 1H, J = 5.2 Hz, H-30), 5.83 (dd, 1H, J = 5.2 and 3.8 Hz, H-20),
6.11 (d, 1H, J = 3.7 Hz, H-10), 6.88 (d, 2H, J = 8.8 Hz, H-Ar), 7.67 (d,
2H, J = 8.8 Hz, H-Ar), 7.81 (s, 1H, H-triazole); 13C NMR (50 MHz,
CDCl3): d (ppm) = 20.4, 20.5, 20.7, 55.3, 62.8, 70.7, 74.3, 80.9,
90.0, 114.3, 117.9, 122.7, 127.1, 148.0, 159.8, 169.3, 169.4, 170.4.
References
4.2.12. 10-(4-Cyclopropyl-[1,2,3]-triazol-1-yl)-20,30,50-tri-O-acetyl-b-
D-ribofuranose (4l)
[1] (a) For reviews on the chemistry, biochemistry and synthesis of nucleoside
analogs see J. Stambasky, M. Hocek, P. Kocovsky, Chem. Rev. 109 (2009) 6729;
(b) K.A. Watanabe, in: L.B. Townsend (Ed.), Chemistry of Nucleosides and
Nucleotides, Vol. 3, Plenum Press, New York, 1994, p. 421;
(c) U. Hacksell, G.D.Jr. Daves, Prog. Med. Chem. 22 (1985) 1;
(d) J.G. Buchanan, Prog. Chem. Org. Nat. Prod. 44 (1983) 243.
[2] For review see M. Bourlière, D. Ouzan, M. Rosenheim, M. Doffoël, P. Marcellin,
J-M. Pawlotsky, L. Salomon, F. Fagnani, S. Rouanet, A. Pinta, M. Vray, Antivir.
Ther. 17 (2012) 101.
Mp = 94–95 °C, Rf = 0.26; MS (ESI+): m/z = 390.9 [M + Na]+, 757.2
[2 M + Na]+; HRMS (ESI+): calcd for C16H21N3O7H+ 368.14523,
found 368.14590; 1H NMR (200 MHz, CDCl3): d (ppm) = 0.70–
0.95 (m, 4H, CH2 cycloprop), 1.75–1.95 (m, 1H, CH cycloprop),
2.00 (s, 3H, Ac), 2.05 (s, 6H, 2Ac), 4.13 (dd, 1H, J = 12.0 and
4.0 Hz, H-50), 4.31 (dd, 1H, J = 11.7 and 2.9 Hz, H-50), 4.36–4.45
(m, 1H, H-40), 5.53 (t, 1H, J = 5.2 Hz, H-30), 5.74 (t, 1H, J = 3.9 Hz,
H-20), 6.03 (d, 1H, J = 3.5 Hz, H-10), 7.40 (s, 1H, H-triazole); 13C
NMR (50 MHz, CDCl3): d (ppm) = 6.5, 7.7, 20.3, 20.4, 20.6, 62.8,
70.6, 74.1, 80.6, 89.8, 118.9, 119.3, 169.3, 169.4, 170.3.
[3] (a) E. Van den Neste, G. Van Den Berghe, F. Bontemps, Expert Opin. Investig.
Drugs 19 (2010) 571;
(b) B.G. Drew, B.A. Kingwell, Expert Opin. Pharmacother. 9 (2008) 2137;
(c) A.F. Santidrián, D.M. González-Gironès, D. Iglesias-Serret, L. Coll-Mulet,
A.M. Cosialls, M. de Frias, C. Campàs, E. González-Barca, E. Alonso, V. Labi, B.
Viollet, A. Benito, G. Pons, A. Villunger, J. Gil, Blood 116 (2010) 3023.

1138
M. Driowya et al. / Ultrasonics Sonochemistry 19 (2012) 1132–1138
[4] E. De Clercq, Med. Res. Rev. 29 (2009) 611.
[13] (a) Y. Jiang, X. Chen, L. Qu, J. Wang, J. Yuan, S. Chen, X. Li, C. Qu, Ultrason.
Sonochem. 18 (2011) 527;
[5] (a) For a brief overview of the biological and clinical impact of tiazofurin, see
M. Grifantini, Curr. Opin. Investig. Drugs 1 (2000) 257;
(b) K. Malek, M. Boosalis, K. Waraska, B.S. Mitchell, D.G. Wright, Leuk. Res. 28
(2004) 1125;
(b) G. Cravotto, V.V. Fokin, D. Garella, A. Binello, L. Boffa, A. Barge, J. Comb.
Chem. 12 (2010) 13;
(c) K.M. Al-Zaydi, Ultrason. Sonochem. 16 (2009) 805;
(d) H.A. Stefani, A.S. Vieira, M.F.Z.J. Amaral, L. Cooper, Tetrahedron Lett. 52
(2011) 4256.
(c) G. Weber, N. Prajda, M. Abonyi, K.Y. Look, G. Tricot, Anticancer Res. 16
(1996) 3313;
(d) G. Tricot, G. Weber, Anticancer Res. 16 (1996) 3341–3348.
[6] (a) Y. Xia, Y. Liu, P. Rocchi, M. Wang, Y. Fan, F. Qu, J.L. Iovanna, L. Peng, Cancer
Lett. (2012), http://dx.doi.org/10.1016/j.canlet.2011.09.043;
(b) D. Stokmaier, O. Khorev, B. Cutting, R. Born, D. Ricklin, T.O.G. Ernst, F. Böni,
K. Schwingruber, M. Gentner, M. Wittwer, M. Spreafico, A. Vedani, S. Rabbani,
O. Schwardt, B. Ernst, Bioorg. Med. Chem. Lett. 20 (2010) 5979;
(c) M. Wang, Y. Xia, Y. Fan, P. Rocchi, F. Qu, J.L. Iovanna, L. Peng, Bioorg. Med.
Chem. Lett. 20 (2010) 5979;
[14] (a) For review see F. Amblard, J.H. Cho, R.F. Schinazi, Chem. Rev. 109 (2009)
4207;
(b) A. Mieczkowski, V. Roy, L.A. Agrofoglio, Chem. Rev. 110 (2010) 1828;
(c) Selected article Yuting Fan, Yi Xia, Jingjie Tang, Palma Rocchi, Qu Fanqi,
Juan Iovanna, Ling Peng, Org. Lett. 12 (2010) 5712;
(d) L. Kiss, E. Forro, R. Sillanpää, Ferenc Fülöp, Tetrahedron 66 (2010) 3599;
(e) J. Broggi, H. Kumamoto, S. Berteina-Raboin, S.P. Nolan, L.A. Agrofoglio, Eur.
J. Org. Chem. 12 (2009) 1880;
(d) K. El Akri, K. Bougrin, J. Balzarini, A. Faraj, R. Benhida, Bioorg. Med. Chem.
Lett. 17 (2007) 6656;
(e) Y. Saito, V. Escuret, D. Durantel, F. Zoulim, R.F. Schinazi, L.A. Agrofoglio,
Bioorg. Med. Chem. Lett. 11 (2003) 3633.
(f) J. Broggi, N. Joubert, S. Dıez-Gonzalez, S. Berteina-Raboin, T. Zevaco, S.P.
Nolan, L.A. Agrofoglio, Tetrahedron 65 (2009) 1162;
(g) U. Pradere, V. Roy, T.R. McBrayer, R.F. Schinazi, L.A. Agrofoglio, Tetrahedron
64 (2008) 9044;
[7] R. Huisgen, A. Padwa (Eds.), 1,3-Dipolar Cycloadditional Chemistry, vol. 1,
Wiley, New York, 1984. pp. 1–176.
(h) B.L. Wilkinson, H. Long, E. Sim, A.J. Fairbanks, Bioorg. Med. Chem. Lett. 18
(2008) 6265;
[8] (a) K.T. Finley, J.A. Montgomery (Eds.), 1,2,3-Triazoles In The Chemistry of
Heterocyclic Compounds, vol. 39, John Wiley & Sons, New York, 1980;
(b) S.J. Howell, N. Spencer, D. Philp, Tetrahedron 57 (2001) 4945.
[9] (a) V.V. Rostovtsev, L.G. Green, V.V. Fokin, K.B. Sharpless, Angew. Chem. Int. Ed.
41 (2002) 2596;
(b) C.W. Tornoe, C. Christensen, M.J. Meldal, J. Org. Chem. 67 (2002) 3057.
[10] (a) C.O. Kappe, E. Van der Eycken, Chem. Soc. Rev. 39 (2010) 1280;
(b) A.K. Feldman, B. Colasson, V.V. Fokin, Org. Lett. 6 (2004) 3897;
(c) P. Appukkuttan, W. Dehaen, V.V. Fokin, E.V. Eycken, Org. Lett. 6 (2004)
4223;
(i) P. Chittepu, V.R. Sirivolu, F. Seela, Bioorg. Med. Chem. Lett. 16 (2008) 8427;
(j) Robert.A. Scism, Donald.F. Stec, Brian O Bachmann, Org. Lett. 9 (2007)
4179;
(k) N. Joubert, R.F. Schinazi, L.A. Agrofoglio, Tetrahedron 61 (2005) 11744.
[15] (a) M. Duca, V. Malnuit, F. Barbault, R. Benhida, Chem. Comm. 46 (2010) 6162;
(b) V. Malnuit, M. Duca, A. Manout, K. Bougrin, R. Benhida, Synlett 13 (2009)
2123;
(c) C. Peyron, J.M. Navarre, D. Dubreuil, P. Vierling, R. Benhida, Tetrahedron
Lett. 49 (2008) 6171;
(d) M. Spadafora, A. Burger, R. Benhida, Synlett 8 (2008) 1225;
(e) M. Spadafora, V. Postopalenko, A. Klemchenko, Y. Mély, A. Burger, R.
Benhida, Tetrahedron 65 (2009) 7809;
(d) K. Kacprzak, Synlett 6 (2005) 943.
[11] (a) E.A. Muravyova, S.M. Desenko, V.I. Musatov, I.V. Knyazeva, S.V. Shishkina,
O.V. Shishkin, V.A. Chebanov, J. Comb. Chem. 9 (2007) 797;
(b) G. Cravotto, P.J. Cintas, Chem. Soc. Rev. 35 (2006) 180;
(c) J.T. Li, Y. Yin, L. Li, M.X. Sun, Ultrason. Sonochem. 17 (2010) 11.
[12] (a) A.A.O. Sarhan, C. Bolm, Chem. Soc. Rev. 38 (2009) 2730;
(b) B.D. Sherry, A. Fürstner, Acc. Chem. Res. 41 (2008) 1500;
(c) W. Liu, H. Cao, A. Lei, Angew. Chem. Int. Ed. 49 (2010) 1.
(f) R. Guezguez, K. Bougrin, K. El Akri, R. Benhida, Tetrahedron Lett. 47 (2006)
4807.
[16] G. Robert, I. Ben Sahra, A. Puissant, P. Colosetti, N. Belhacene, P. Gounon, P.
Hoffman, F. Bost, J.P. Assuto, P. Auberger, PLoS One 4 (2009) 7889.