Efficient click chemistry towards novel 1H-1,2,3-triazole-tethered 4H-chromene?D-glucose conjugates: Design, synthesis and evaluation of in vitro antibacterial, MRSA and antifungal activities

Article abstract of DOI:10.1016/j.ejmech.2019.01.060

The series of 2-amino-7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were synthesized from corresponding 2-amino-7-phydroxy-4H-chromene-3-carbonitriles 4a-t and propargyl bromide. Two procedures were used in these syntheses: K₂CO₃/acetone and NaH/DMF procedures with yields of 65–89% and 80–96%, respectively. 1H-1,2,3-Triazole-tethered 4H-chromene?D-glucose conjugates 7a-t were synthesized using click chemistry of propargyl ethers 5a-t and tetra-O-acetyl-β-D-glucopyranosyl azide. Cu@MOF-5 was the optimal catalyst for this chemistry. The yields of 1H-1,2,3-triazoles were 80–97.8%. All triazoles 7a-t were evaluated in vitro for anti-microorganism activities. Among tested compounds with MIC values of 1.56–6.25 μM, there were four compounds against B. subtilis, four compounds against S. aureus, and four compounds against S. epidermidis; five compounds against E. coli, four compounds against K. pneumoniae, five compounds against P. aeruginosa, and six compounds against S. typhimurium. Compounds 7c,7d,7f,7h, and 7r had MIC values of 1.56–6.25 μM for three clinical MRSA isolates. Some compounds had inhibitory activities against four fungi, including A. niger, A. flavus, C. albicans, and S. cerevisiae, with MIC values of 1.56–6.25 μM. Some 1H-1,2,3-triazoles had comparatively low toxicity against RAW 264.7 cells.

Full text of DOI:10.1016/j.ejmech.2019.01.060

Accepted Manuscript
Efficient click chemistry towards novel 1H-1,2,3-triazole-tethered 4H-chromene−d-
glucose conjugates: Design, synthesis and evaluation of in vitro antibacterial, MRSA
and antifungal activities
Nguyen Dinh Thanh, Do Son Hai, Vu Thi Ngoc Bich, Pham Thi Thu Hien, Nguyen Thi
Ky Duyen, Nguyen Thi Mai, Tran Thi Dung, Vu Ngoc Toan, Hoàng Thi Kim Van, Le
Hai Dang, Duong Ngoc Toan, Tran Thi Thanh Van
PII:
S0223-5234(19)30055-8
DOI:
https://doi.org/10.1016/j.ejmech.2019.01.060
EJMECH 11067
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 16 October 2018
Revised Date: 19 December 2018
Accepted Date: 17 January 2019
Please cite this article as: N.D. Thanh, D.S. Hai, V.T. Ngoc Bich, P.T. Thu Hien, N.T. Ky Duyen, N.T.
Mai, T.T. Dung, V.N. Toan, Hoà.Thi. Kim Van, L.H. Dang, D.N. Toan, T.T. Thanh Van, Efficient click
chemistry towards novel 1H-1,2,3-triazole-tethered 4H-chromene−d-glucose conjugates: Design,
synthesis and evaluation of in vitro antibacterial, MRSA and antifungal activities, European Journal of
Medicinal Chemistry (2019), doi: https://doi.org/10.1016/j.ejmech.2019.01.060.
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ACCEPTED MANUSCRIPT
Graphic abstract

ACCEPTED MANUSCRIPT
Efficient click chemistry towards novel 1H-1,2,3-triazole-tethered 4H-
chromene−
D-glucose conjugates: Design, synthesis and evaluation of in vitro
antibacterial, MRSA and antifungal activities
a
a,b
a
a
Nguyen Dinh Thanh* , Do Son Hai , Vu Thi Ngoc Bich , Pham Thi Thu Hien , Nguyen Thi Ky
a
a
a
a,c
a,d
Duyen , Nguyen Thi Mai , Tran Thi Dung , Vu Ngoc Toan , Hoàng Thi Kim Van , Le Hai
a,e
a,f
a
Dang , Duong Ngoc Toan , Tran Thi Thanh Van
a
Faculty of Chemistry, VNU University of Science (Vietnam National University, Ha Noi), 19 Le
Thanh Tong, Hoan Kiem, Ha Noi, Viet Nam.
b
Lab of Profession Chemistry, Institute of Biochemical Technology and Profession Documents,
General Department 4 (Ministry of Public Security), 80 Tran Quoc Hoan, Cau Giay, Ha Noi, Viet
Nam.
c
Institute for Chemistry and Materials, Military Institute of Science and Technology, 17 Hoang
Sam, Cau Giay, Ha Noi, Viet Nam.
d
Viet Tri University of Industry, Tien Kien, Lam Thao, Phu Tho, Viet Nam
e
Thai Nguyen College of Education, Quang Trung, Thinh Dan, Thai Nguyen, Viet Nam
f
Faculty of Chemistry, Thai Nguyen University of Education, 20 Luong Ngoc Quyen, Thai
Nguyen, Viet Nam
Abstracts. The series of 2-amino-7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were
synthesized from corresponding 2-amino-7-phydroxy-4H-chromene-3-carbonitriles 4a-t and
propargyl bromide. Two procedures were used in these syntheses: K CO /acetone and NaH/DMF
2
3
procedures with yields of 65−89% and 80−96%, respectively. 1H-1,2,3-Triazole-tethered 4H-
chromene−D-glucose conjugates 7a-t were synthesized using click chemistry of propargyl ethers
1

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-glucopyranosyl azide. Cu@MOF-5 was the optimal catalyst for this
5
a-t and tetra-O-acetyl-β-
D
chemistry. The yields of 1H-1,2,3-triazoles were 80−97.8%. All triazoles 7a-t were evaluated in
vitro for anti-microorganism activities. Among tested compounds with MIC values of 1.56‒6.25
µM, there were four compounds against B. subtilis, four compounds against S. aureus, and four
compounds against S. epidermidis; five compounds against E. coli, four compounds against K.
pneumoniae, five compounds against P. aeruginosa, and six compounds against S. typhimurium.
Compounds 7c,7d,7f,7h, and 7r had MIC values of 1.56−6.25 µM for three clinical MRSA
isolates. Some compounds had inhibitory activities against four fungi, including A. niger, A.
flavus, C. albicans, and S. cerevisiae, with MIC values of 1.56−6.25 µM. Some 1H-1,2,3-triazoles
had comparatively low toxicity against RAW 264.7 cells.
Keywords. 1H-1,2,3-Triazoles; 2-Amino-4H-chromene-3-carbonitriles; Propargyl ether; Sugar
azide; Cu@MOF-5; Click chemistry; Antibacterial; Antifungal; Cytotoxicity.
1. Introduction
Organic compounds bearing chromene ring exhibit a wide range of biological activities, especially
with certain functional groups, such amino, nitrile,… in its molecular skeleton that could be
effectively bound to enzyme receptor sites [1-3]. These compounds function as important
pharmacophores, which are associated with a broad range of pharmacological activities, including
anticancer [3], antimicrobial [4], cytotoxicity [4], anti-proliferative [5], antitumor [6], antibacterial
[
7, 8], antioxidant [7], antiviral [9] agents, and so on. A large number of synthetic 2-
aminochromene derivatives have shown remarkable biological activities that some representative
compounds were given in Fig. 1. Kumar et al. [10] showed that tetrahydrochromene A had
antibacterial activity against Escherichia coli and Staphylococcus aureus with MIC value of 64
µg/mL. Kidwai et al. indicated that chromenes B bearing benzothiazolyl-2 had antibacterial
activity against both Gram-(−), such as E. coli and Pseudomonas aeruginosa, and Gram-(−), such
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as S. aureus and Staphylococcus epidermidis [11]. Mirjalili et al. synthesized benzo[f]chromene C,
which had antifungal activity against Aspergillus flavus and Candida albicans with MIC < 1
µg/mL [12]. Makawana et al. [13] showed that chromene D (Fig. 1) was especially active against
Gram-negative bacteria Vibrio cholerate (MIC = 12.5 µg/mL), whereas chromene E was more
active against Gram-positive Streptococcus pneumonia (MIC = 12.5 µg/mL) as compared to
ampillicin (MIC = 100 µg/mL for both strains). Therefore, synthetic procedures of derivatives with
chromene moiety have been developed due to their useful biological activities [14, 15].
Figure 1
1
H-1,2,3-Triazole are an important class of nitrogen-containing heterocycles in the area of organic
chemistry) and medicinal chemistry. Medicinally, they showed a broad range of diverse,
interesting pharmacological properties such as antiinfective [9], antituberculosis [16], anticancer
17], antifungal [18], and antibacterial [19], antimicrobial [20], antioxidant [21] activities, and so
(
[
on. The connection of some heterocycles, such as chromene and 1H-1,2,3-triazole rings, even
monosaccharide, could bring forth some interesting biological activities. Sangshetti et al. [22]
showed that triazole F (Fig. 2) had inhibitory activities against some fungi, such as C. albicans
(MIC = 30 µg/mL), A. niger (MIC = 15 µg/mL) and A. flavus (MIC = 15 µg/mL) in comparison to
fluconazole (MIC = 5 µg/mL for all strains). Yadav et al. [23] indicated that chalcone-12,3-triazole
conjugate G exhibited inhibition activity against serial organisms with MIC = 0.0032−0.0063
µg/mL. Chaudhary et al. [24] synthesized several novel 1,4-disubstituted-1,2,3-triazolyluridine
derivatives (H, Fig. 2), which showed significant antifungal activity. One of the compounds H
showed potent antifungal activity against C. neoformans with an MIC value of 8 µg/mL. The other
one with 4-methoxy group had antifungal activity against C. albicans with MIC value of 24 µg/mL
in comparison to MIC = 0.018 µg/mL for fluconazole), whereas the compound having 4-chloro
group showed antifungal activity against F. oxysporum with MIC = 32 µg/mL.
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Figure 2
Saeedi et al. [25] showed that compound I (Fig. 2) that had chromene and 1H-1,2,3-triazole rings
exhibited good anti-acetylcholinesterase activity, with IC = 15.42 µM. Similarly, Shaikh et al.
5
0
[
26] synthesized some triazoles J (Fig. 2) with remarkable antifungal and antioxidant activities.
Some potential pharmaceuticals were based on 1,2,3-triazole ring, including the anticancer agent
CAI (carboxyamidotriazole, K, Fig. 3) [27], TSAO [2ʹ,5ʹ-bis-O-(tert-butyldimethylsilyl)-3ʹ-spiro-
5
ʹʹ-(4ʹʹ-amino- 1ʹʹ,2ʹʹ-oxathiole-2ʹʹ,2ʹʹ-dioxide)]-β-D-ribofuranose, L, Fig. 3), a nucleoside
derivative non-nucleoside reverse transcriptase inhibitor [28], and tazobactam (M, Fig. 3), one β-
lactam antibiotic drug, and so on.
Figure 3
The heterocyclic aromatic ring 1H-1,2,3-triazole ring is formed through click chemistry of
appropriate alkynes-1 and organic azides, which was often catalyzed by copper [29-32]. Copper-
catalyzed azide-alkyne cycloaddition (CuAAC) is a type of Huisgen 1,3-dipolar cycloaddition
[
30]. Some copper-catalysts in free metal or salt forms (ionic or complex) were employed for most
effective promotion of CuAAC processes, such Cu(II) sulfate/sodium ascorbate [32], CuI/DIEA
N,N-diisopropylethylamine) [33], copper(II) acetate or triflate/sodium ascorbate [34, 35],
(
CuCl /PMDETA (pentamethyldiethylenetriamine) [36], CuNPs/C (copper nanoparticles on
2
activated carbon) [37], etc… The same catalysts also were employed in click chemistry of
carbohydrate [38].
In order to find some hybrid structures between chromene and 1H-1,2,3-triazole rings having
bacterial and fungal activities, we reported the synthesis of 1H-1,2,3-triazole-tethered 4H-
chromene and
D-glucose conjugates and the evaluation of their anti-microorganism activity. These
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triazoles were obtained by the click chemistry of 2-amino-4-aryl-7-propargyl-4H-chromene-3-
carbonitriles to and D-glucose moiety. They were evaluated by their antibacterial and fungal
activities against some Gram-positive bacteria, such as Bacillus subtilis, Staphylococcus aureus,
Staphylococcus epidermidis, some Gram-negative bacteria, such as Escherichia coli,
Pseudomonas aeruginosa, Klebsiella pneumonia, Salmonella typhimurium, and some fungi, such
as Aspergillus niger, Aspergillus flavus, Candida albicans, and Saccharomyces cerevisiae. These
compounds were also tested their cytotoxicity against RAW 264.7 cells [39-42].
2
2
2
. Results and discussion
.1. Chemistry
-Amino-4-aryl-7-hydroxyl-4H-chromene-3-carbonitriles 4a-t were prepared by three-component
reaction of (un)substituted benzaldehydes 1a-t, malononitrile 2, and resorcinol 3 (Scheme 1). The
three-component reaction process took place at room temperature (25°C) for 24 h. The basic
catalyst for this reaction was sodium carbonate in water (44.7 mol%, i.e. ~0.47% solution). The
yields were 62−90% (Table 1S, including their spectral and analytical data, Section 4,
Supplementary data in the online version of this article).
Scheme 1
2
-Amino-7-propargyloxy-4-aryl-4H-chromene-3-carbonitriles 5a-t, which were the precursors
necessary for CuAAC click chemistry, were synthesized by reaction of corresponding 7-hydroxyl-
H-chromene 4a-t with propargyl bromide. We used two synthetic ways in order to accomplish
4
this purpose (Scheme 2). In the first way, anhydrous potassium carbonate was used as a base and
dried acetone was used as a solvent (Procedure A). The reaction time was 12 hours at 50°C, and
the yields were 65−89%. In the second way, sodium hydride was used as a base in dried DMF
solvent (Procedure B). In Procedure B, the formation of ether 5a-t took place via reaction of 4a-t
5

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with sodium hydride to form sodium phenoxides, named sodium 2-amino-3-cyano-4-phenyl-4H-
chromene-7-olates 4ʹa-t, which were dissolved well in DMF and could not be isolated and allowed
to react with propargyl bromide to afford the target ethers 5a-t. The reaction time was only 2 hours
at a temperature of 25°C, and the yields obtained were 80−96%. The synthesized 2-amino-4-aryl-
7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were shown in Table 1. Their spectral and
analytical data were given in Section 5 (Supplementary data, in the online version of this article).
Scheme 2
Table 1
The spectral data showed that in the reaction with propargyl bromide, the O-alkylation of the
hydroxyl group on position 7 of benzene moiety of chromene ring occurred instead of the N-
alkylation of the primary amino group on position 2 of pyran moiety of chromene ring.
Crystals for the compound 5i (2-amino-7-propargyloxy-4-(2ʹ-chlorophenyl)-4H-chromene-3-
carbonitrile) were grown by slow evaporation technique using a mixture of 96% ethanol and
toluene as a solvent system (4:1 by volumes). The X-ray diffraction data showed that the crystal of
5i had the same empirical formula and formula weight (Table 2). The crystal data of 5i can be
accessed at www.ccdc.cam.ac.uk/data_request/cif under Crystallographic Data Centre number
CCDC 1854537 (for crystallographic details, see Section 6.1, Supplementary data in online
version of this article). The ORTEP diagram of 5i was given in Fig. 4.
Table 2
Figure 4
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The other precursor for the click chemistry was 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl azide 6,
which was prepared by the reaction of tetra-O-acetyl-α-
43](acetobromo-α- -glucose) with sodium azide in dried DMF [44] or acetone-water [45]. We
have prepared this sugar azide with some modifications of the known procedure (Scheme 3). Dried
acetone was used as a solvent, which avoided the decomposition of acetobromo-α- -glucose by
D-glucopyranosyl bromide
[
D
D
water, and acetone was easily removed from the reaction mixture. This sugar azide derivative was
obtained as a crystalline solid on a multi-gram scale.
Scheme 3
The single-crystal X-ray structure of this azide was shown in Table 2 and Fig. 5 with CCDC
number is 1855316, www.ccdc.cam.ac.uk/data_request/cif (see Section 6.2, Supplementary data in
the online version of this article), which was similar to the azide compound that was synthesized
and structurally determined by D. P. Temelkoff et al. [46].
Figure 5
From the literature, the click chemistry could be catalyzed by some different catalysts [38]. In
order to find the optimal conditions for the click chemistry of propargyl ether of 4H-chromene-3-
carbonitriles 5a-t with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl azide 6, we have carried out
investigations of the CuAAC catalytic conditions in the reaction of the compound 7a (R = H) with
this azide (Scheme 4). The catalysts used included CuSO .5H O/sodium ascorbate, CuIm (Im =
4
2
2
imidazole), CuI, CuNPs (Cu nano-particles on Montmorillonite K10), and Cu@MOF-5. Some
copper catalysts that were utilized in these examinations were prepared in our lab and
characterized structurally, except (for the) CuSO /sodium ascorbate system. The obtained
4
7

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examination results are shown in Table 3.
Scheme 4
Table 3
The use of the catalytic system of CuSO .5H O (2 mol%) and sodium ascorbate (5 mol%) in
4
2
DMSO as solvent (Procedure A, Entry 1, Table 3) made it difficult to handle the reaction, even
with the solvent-extraction method being used to isolate the product out of the reaction mixture.
On the other hand, reaction time prolonged until 24 hours when the reaction was carried out at
room temperature. The yield of 7a was 60.7% in this case. The increasing of reaction temperature
(only to ~40°C) led to the formation of oily or tar substances having indefinite structures possibly
due to the decomposition of the reactants and/or products.
The catalysis of CuIm (2 mol%) in Entry 2 (Procedure B), which was a complex of copper (II) ion
2
and imidazole, gave an only low yield of 7a (53.3%) after 1.5-hour heating at 79−80°C in absolute
ethanol as solvent. The other CuAAC catalyst systems (Entries 3−5, Table 3) seemed to be
preeminent because the treatment of those reactions became easier and produced higher yields
since copper did not affect the reaction treatment. Thus, (the) product was easily isolated. The use
of nano-structured copper catalyst that supported on montmorillonite K-10 had more advantages in
comparison to the catalytic CuSO /sodium ascorbate system in Entry 1. The reaction time was
4
only 30 min and gave high product yields (up to 94.8%). In this reaction, trimethylamine was often
used as an additive. The products were isolated more easily. Usually, water was added to the
reaction mixture, and the separated precipitates were filtered simply. These conveniences were
also achieved by using the catalyst of copper(I) iodide (2 mol%) in t-BuOH as a solvent with a
little of water as an additive (Entry 3, Procedure D). However, the reaction time was prolonged
(until 1 hour) and a yield of 94.8% was attained. In the last examination, copper was supported on
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microporous metal-organic frameworks MOF), and in this case, Cu@MOF-5 (2 mol%) (Procedure
E, Entry 5) gave the best results of the catalyst surveyed. The reaction temperature was 79−80°C.
On the other hand, the use of absolute ethanol brought in outstanding advantages in this entry.
After the end of the reaction, the product was isolated simply by adding toluene (by half a
volume), heating and filtering out solid catalyst. The obstructions of the copper salts to isolating
products have been avoided. The yield of 97.8% was attained when this procedure was employed.
Based on the above results of examinations, we decided to choose Cu@MOF-5 to be a catalyst in
the synthesis of remained substituted 1H-1,2,3-triazoles 7b-t. The obtained synthetic results were
shown in Table 4. The product yields were 80−97.8%.
Table 4
1
13
The assignments proton and carbon-13 signals in H NMR and C NMR spectra were done based
on HSQC and HMBC of compound 7a (see Section 8.1, Supplementary Data in online version of
this article). The spectral data confirmed the formation of 1H-1,2,3-triazole ring via click
chemistry and the presence of 4H-chromene and glucopyranose rings.
2.2. Biological screening
2.2.1. Antibacterial assays
All the synthesized 1H-1,2,3-triazoles were screened for their in vitro antibacterial activity against
three representative Gram-positive bacteria, which were B. subtilis (ATCC 11774), S. aureus
(ATCC 11632), S. epidermidis (ATCC 12228), and representative four Gram-negative bacteria,
which were E. coli (ATCC 25922), P. aeruginosa (ATCC 25923), K. pneumoniae (ATCC 4352),
S. typhimurium (ATCC 14028). Three methicillin resistant Staphylococcus aureus (MRSA) strains
isolated from Hospital of Ministry of Public Security (in Ha Noi), numbered MRSA198-1,
MRSA198-2 and MRSA198-3, were also included in these tests. Ciprofloxacin, methicillin and
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vancomycin were used as positive references for antibacterial activity. It is known that methicillin
was used to treat infections caused by certain gram-positive bacteria, including S. aureus, S.
epidermidis, S. pyogenes, and S. pneumoniae. (However,) methicillin is no longer effective against
these mircoorganisms due to resistance. Vancomycin and ciprofloxacin are still used to treat a
number of bacterial infections, with the former used to treat serious, life-threatening infections by
Gram-positive bacteria (, including C. difficile?) that (are) unresponsive to other antibiotics. The
latter treated serious infections caused by Gram-negative bacteria, including P. aeruginosa.
Evaluated results for 7a-t were given in Table 5.
Table 5
The results in Table 5 showed that almost all novel molecule exhibited antibacterial activity
against the tested bacteria at low and high concentrations. In general, it has been observed that
almost all tested compounds showed mild to moderate activity against the tested bacteria in
comparison with the MIC values of the references compound. MIC values of these reference drugs
are as follows: Ciprofloxacin, 3.12 µM (for Gram-positive bacteria), 1.56 µM (for Gram-negative
bacteria); vancomycin, 0.78−3.12 µM (for Gram-positive bacteria), 3.12 µM (for Gram-negative
bacteria). Methicillin had the least inhibitory activity for all tested bacteria (all MICs = 400 µM).
Some 1H-1,2,3-triazoles had higher ability to inhibit to Gram-positive bacteria (B. subtilis, S.
aureus and S. epidermidis) with MIC values of 1.56‒6.25 µM. Amongst these triazoles were
compounds 7f (MIC = 3.12 µM), 7h (MIC = 6.25 µM), 7i (MIC = 1.56 µM) against B. subtilis.
Compounds 7c,7h,7r had activity against S. aureus with MIC values of 6.25, 3.12 and 3.12 µM,
respectively. Compounds 7i,7p,7s,7t were more active against S. epidermidis with MIC values of
3
.12, 6.25, 1.56 and 3.12 µM, respectively. In general, the above-mentioned triazoles were more
inhibitory active than ciprofloxacin but less than vancomycin, except 7i,7h,7r, and 7s (MICs =
.56 µM). Some others were less active against these bacteria with MIC values of 12.5−25 µM,
1
1
0

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such as 7h,7l,7n,7q (against B. subtilis), 7d,7f,7q (against S. aureus), 7d,7i,7p (against S.
epidermidis). The remaining triazoles had MIC values of 100−400 µM or higher (not evaluated).
Several triazoles had inhibitory activity against each Gram-negative bacterium similar to
ciprofloxacin, with MIC value of 1.56 µM, such as 7g,7i (against E. coli), 7l (against K.
pneumoniae), 7m (against P. aeruginosa), and 7n (against S. typhimurium). The compounds
mentioned herein were more active than vancomycin (MIC = 3.12 µM) and methicillin (MIC =
4
00 µM) for all tested Gram-negative bacteria. The triazoles that had less inhibitory activity
against these bacteria (with MICs = 3.12−6.25 µM) included 7f,7h,7s (against E. coli); 7h,7o,7p
against K. pneumoniae); 7e,7g,7l,7p (against P. aeruginosa), and 7a,7f,7h,7i,7p (against S.
typhimurium). Thus, the synthesized 1H-1,2,3-triazole-tethered 4H-chromene− -glucose
(
D
conjugates were more inhibitory active against Gram-negative bacteria than Gram-positive ones.
We have evaluated the antibacterial activities of these triazoles against a series of MRSA strains
(MRSA198-1, MRSA198-2 and MRSA198-3) from clinical sources. Among the tested
compounds, 7c, 7d, 7f, 7h and 7r exerted anti-MRSA activities against all the strains tested with
MIC values ranging from 1.56 to 6.25 µM. In addition, the inhibitory effects of triazoles 7c, 7h
and 7r were obviously observed by treating it against strain MRSA198-1 with MIC values of 1.56,
3.12 and 1.56 µM, respectively. Triazoles 7d, 7f and 7r had the better inhibition activity against
strain MRAS198-2 with all MIC values of 1.56 µM. Triazoles 7c, 7d, 7f, and 7h also had better
inhibition activity against strain MRAS198-3 with MIC values of 3.12, 3.12, 3.12 and 1.56 µM,
respectively. Compounds 7d, 7f, 7j, 7n (against MRSA 198-1), 7c, 7h, 7j, 7n (against MRSA 198-
2), and 7j, 7r, 7n (against MRSA 198-3) showed mild anti-MRSA effect with MIC values of
6.25−12.5 µM. Other compounds did not show any significance in anti-MRSA activity (MIC =
25−400 µM or not evaluated) (Table 6). Some triazoles had better activity against Gram-positive,
Gram-negative and MRSA bacteria, such as 7f,7h, and 7i, with MIC values of 1.56−6.25 µM,
respectively.) Amongst these compounds were 7f and 7h, which had inhibitory activity against
(
1
1

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hospital-isolated MRSA strains (MICs = 1.56−6.25 µM). Triazoles 7c and 7r were more
inhibitory-active against both S. aureus and MRSA (Table 5, Fig. 6).
Figure 6
Some obtained SAR results were as follows:
1
. The electron-withdrawing groups on the benzene ring: Gram-positive antibacterial activity
against B. subtilis increased, with MICs = 1.56−6.25 µM, except compounds with nitro-group,
such as 7b−7c (MICs = 50−100 µM), and the ones bearing 4ʹ-chloro and 4ʹ-bromo groups
(
MICs = 400 and 200 µM, respectively). The compounds with electron-withdrawing groups had
also higher activity against S. aureus and S. epidermidis, except 7b, 7i (for S. aureus), and
c,7e,7g,7j (for S. epidermidis). These observations were also true for Gram-negative bacteria,
except some cases, such as triazoles 7b,7e,7j (for E. coli), 7c−7f,7i,7j (for K. pneumoniae), 7d
for P. aeruginosa), (and) 7b−7d,7j (for S. typhimurium).
7
(
2
. The electron-donating groups on the benzene ring: Alkyl groups (such as methyl, isopropyl) and
dimethylamino group in general decreased the inhibitory activity against Gram-positive
bacteria, except compound 7l (for B. subtilis). One methoxy group on the benzene ring
increased unnoticeably the inhibitory activity against Gram-positive bacteria, except 7n (for B.
subtilis) and 7p (for S. epidermidis), and decreased this activity (against) Gram-negative
bacteria, except 7p (for K. pneumoniae, P. aeruginosa, S. typhimurium) (and) 7n (for S.
typhimurium).
3
. The increasing numbers of methoxy groups on the benzene ring led to increased Gram-positive
antibacterial activity, except compounds 7r,7s (for S. aureus, MICs = 1.56 µM), and to
decreased Gram-negative antibacterial activity, except 7s (for E. coli, MIC = 6.25 µM).
2.2.2. Antifungal assay
1
2

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We evaluated the antifungal activities of the above 1H-1,2,3-triazoles 7a-t against some fungi,
such as Aspergillus niger (ATCC 439), Aspergillus flavus (ATCC 204304), Candida albicans
(ATCC 7754), and Saccharomyces cerevisiae (SH 20). Miconazole and fluconazole were used as
references. Miconazole is mainly used externally for the treatment and prophylactic treatment of
Candida infection in the oral cavity and the digestive tract. Fluconazole is a first-generation
triazole antifungal medication. It has a spectrum of activity, which includes most Candida species
but not C. krusei or C. glabrata, Cryptococcus neoformans, some dimorphic fungi, and
dermatophytes. MIC values of miconazole were 1.56, 1.56, 3.12 and 3.12 µM for each fungus,
respectively, and of fluconazole were 1.56, 0.78, 0.78 and 0.78 µM for each fungus, respectively.
The obtained results were given in Table 6. Notably, almost all of the tested triazoles 7a-t were
more remarkably active against fungi A. flavus, C. albicans, and S. cerevisiae, but those triazoles
were more resistant to A. niger than miconazole and fluconazole. In the case of fungi A. niger,
almost all of the compounds were less active than miconazole and fluconazole, except for triazole
7p that was as active as these references, with an MIC value of 1.56 µM. Seven compounds
7
b,7c,7g,7h,7j,7k,7t were active against S. cerevisiae with MICs= 1.56−6.25 µM. Some triazoles
had more inhibitory activity against these fungi with MIC = 1.56−3.12 µM, such as 7j,7p (A.
niger), 7b,7k,7o,7s (A. flavus), 7j,7l,7n (C. albicans), and 7b,7g,7h,7j,7k (S. cerevisiae).
Remarkably, compound 7n was more active against C. albicans than miconazole but less active
than fluconazole, and compounds 7g and 7j were more active against S. cerevisiae than
miconazole.
Table 6
Triazoles have the remarkable ability to inhibit these fungi with MIC values of 6.25 µM, such as
7a (A. niger), 7d,7i (A. flavus), and 7g,7s (C. albicans), and 7c,7t (S. cerevisiae). Some triazoles
displayed mild inhibitory activity with MIC values of 12.5 µM, and other ones exhibited even less
1
3

ACCEPTED MANUSCRIPT
inhibitory activity (with MIC values of 25−50 µM). Triazoles were least active with MIC values of
100−200 µM, such as 7e,7k,7n,7s,7t (A. niger), 7a,7e,7h,7j (A. flavus), 7a,7c,7f,7p,7q (C.
albicans), and 7m,7p,7q (S. cerevisiae). The remaining compounds had MIC values of 400 µM for
each fungus and displayed no activity, such as 7b, 7f, 7l, 7m (for A. niger), 7r (for A. flavus), 7k,
7o (for C. albicans), and 7d,7e,7i (S. cerevisiae) (see Table 6, Fig. 7). In general, triazoles that had
bulky groups (methoxy, methyl, isopropyl) in their benzene ring were less active. However, there
are some exceptional cases. Triazole 7p with 2ʹ-methoxy group was more active against A. niger
(MIC = 1.56 µM) but less active against fungus A. flavus and C. albicans. Triazoles 7b (with para-
nitro group) and 7o (with meta-methoxy group) were more active against A. flavus (MICs = 1.56
µM) but less active against S. cerevisiae and not active against both A. niger and C. albicans.
Figure 7
The triazoles bearing monomethoxy-substituted phenyl ring, in general, exhibited mild to most
activity (with MIC = 1.56 µM and 12.5 µM), except 7n, 7o (A. niger), 7p (A. flavus), 7o,7p (C.
albicans). The more introduced methoxy group (compounds 7q-t) reduced the antifungal
inhibitory activity against all tested fungi of these triazoles, except 7s that was more active against
A. flavus and C. albicans, and 7t that was more active against S. cerevisiae.
2.2.3. Cytotoxicity
All 1H-1,2,3-triazoles tethered 4H-chromene-
D
-glucose were also tested for in vitro cytotoxicity
against mouse macrophage (RAW 264.7) cell lines at 50 µg/mL concentration using (4,5-
dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All these compounds
showed less than 50% inhibition. The percentage inhibitions of cells were given in Table 7. The
most promising antitubercular analogs 7c,7d,7f,7h, and 7r exhibited 15.56, 15.45, 18.13, 17.20,
and 12.45% growth inhibition, at 50 µg/mL, respectively. The results indicated that these potent
1
4

ACCEPTED MANUSCRIPT
H-1,2,3-triazoles were comparatively less toxic than other triazoles and it’s suggested that these
1
compounds are suitable subjects for further drug-development studies.
Table 7
3. Conclusions
A series of 2-amino-4-aryl-7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were synthesized by
the reaction of corresponding 2-amino-7-hydroxy-4H-chromene-3-carbonitriles 4a-t through
Williamson’s ether synthesis. Propargyl bromide was used in these syntheses in two procedures:
K CO /acetone and NaH/DMF procedures. Both procedures gave the ethers 5a-t in high yields.
2
3
The single-crystal X-ray structure of propargyl ether 5i has been recorded. This X-ray study helps
to confirm the structure of 2-amino-4-aryl-7-propargyloxy-4H-chromene-3-carbonitriles. Click
chemistry of these propargyl ethers was carried out by reaction with tetra-O-acetyl-β-D-
glucopyranosyl azide by CuAAC process. The catalysts for this chemistry were examined. The
obtained results showed that Cu@MOF-5 was the optimal catalyst for the above chemistry. The
yields of 1H-1,2,3-triazoles 7a-7t were 80−97.8%. All synthesized 1H-1,2,3-triazole-tethered 4H-
chromene−D-glucose conjugates were evaluated for inhibitory activities against some Gram-
positive, Gram-negative bacteria, and fungi. Some compounds had remarkable inhibitory activity
against the tested microorganisms with MIC values of 1.56−6.25 µM. In particular, triazoles
7c,7d,7f,7h, and 7r were active against three clinical MRSA isolates with MIC values of
1.56−6.25 µM. 1H-1,2,3-Triazoles 7b, 7f, 7i, 7j, and 7l are comparatively less toxic against RAW
264.7 cells than other triazoles.
4. Experimental
Melting points were determined by open capillary method on STUART SMP3 (BIBBY
STERILIN, UK). The IR spectra were recorded on FT-IR Affinity-1S Spectrometer (Shimadzu,
1
5

ACCEPTED MANUSCRIPT
1
13
Japan) in KBr pellet. The H and C NMR spectra were recorded on Avance AV500 Spectrometer
(
Bruker, Germany) at 500 MHz and 125 MHz, respectively, using DMSO-d as solvent and TMS
6
as an internal standard. ESI-mass spectra were recorded on LC-MS LTQ Orbitrap XL, ESI/HR-
mass spectra were recorded on Thermo Scientific Exactive Plus Orbitrap spectrometers
(ThermoScientific, USA) in methanol using ESI method. The analytical thin-layer
chromatography (TLC) was performed on silica gel 60 WF S aluminum sheets (Merck,
2
54
Germany) and was visualized with UV light or by iodine vapor. Chemical reagents in high purity
were purchased from the Merck Chemical Company (in Viet Nam). All materials were of reagent
grade for organic synthesis. The procedures for preparation of the copper catalysts (CuI, CuIm2,
CuNPs, Cu@MOF-5), substituted 2-amino-4-aryl-7-hydroxy-4H-chromene-3-carbonitriles (4a-t),
and also tetra-O-acetyl-β-D-glucopyranosyl azide (6) were described in Supplemental Data file (in
the online version of this article).
4.1 General procedure for the synthesis of substituted 2-amino-4-aryl-7-propargyloxy-4H-
chromene-3-carbonitriles
Procedure using potassium carbonate in dried acetone
To a solution of appropriate substituted 2-amino-4-aryl-7-hydroxy-4H-chromene-3-carbonitriles
4a-t (1 mmol) in dried acetone (10 mL) was added anhydrous potassium carbonate (207 mg, 1.5
mmol). Propargyl bromide (1.2 mmol, 143 mg, 0.2 mL of solution 80 wt. % in toluene) then was
added dropwise into this suspension mixture. The reaction mixture was heated with stirring at
50°C on water-bath for 12 h. Then the solvent was evaporated completely in vacuum at the
ambient temperature. Water was added to the residue to dissolve inorganic salts (K CO and KBr).
2
3
The separated solid product was filtered, washed by water and recrystallized from a mixture of
6% ethanol and toluene (1:1 to 1:2, by volumes) to afford the titled substituted 2-amino-4-aryl-7-
propargyloxy-4H-chromene-3-carbonitriles 5a-t.
9
1
6

ACCEPTED MANUSCRIPT
Procedure using sodium hydride in dried DMF
The suspension of sodium hydride (24 mg, 1.5 mmol) in dried DMF (2 mL) was cooled to 0°C,
then appropriate substituted 2-amino-4-aryl-7-hydroxy-4H-chromene-3-carbonitriles 4a-t (1
mmol) was added to the stirred mixture. The reaction mixture became purple color resulting from
the formation of the phenoxide anion of 4H-chromene. The reaction mixture was stirred at room
temperature until hydrogen ceased (for ~40 min). To this reaction mixture was then added
propargyl bromide (1.2 mmol, 143 mg, 0.2 mL of solution 80 wt. % in toluene) in DMF (2 mL)
and stirred at room temperature for 2 h. After the completion of the reaction (monitoring by TLC),
the reaction mixture was quenched by dropwise addition of water (10 mL) and subsequently
extracted with ethyl acetate (3 × 30 mL). The combined organic layers were washed with a brine
solution, dried over anhydrous Na SO and concentrated under reduced pressure. Purification of
2
4
the reaction mixture by recrystallized from a mixture of 96% ethanol and toluene (1:1 to 1:2, by
volumes) to afford the titled substituted 2-amino-4-aryl-7-propargyloxy-4H-chromene-3-
carbonitriles 5a-t that are the novel compounds. The analytical characteristics for the compound
5a,b are shown below. The spectral and analytical data of the remained compounds 5c-t were
given in Section 5 (Supplemental Data file in the online version of this article).
4.1.1. 2-Amino-4-phenyl-7-propargyloxy-4H-chromene-3-carbonitrile (5a)
Ivory solids. From 4a (R = H, 1 mmol, 264 mg) and propargyl bromide (1.2 mmol, 143 mg, 0.2
mL of solution 80 wt.% in toluene). M.p. 288–289°C (from 96% ethanol/toluene 1:1); FT-IR
–
1
1
(
KBr), ν (cm ): 3437, 3333, 3059, 2200, 2133, 1650, 1612, 1501, 1410; H NMR (500 MHz,
DMSO-d ), δ (ppm): 7.34−7.31 (m, 2H, H-2ʹ & H-6ʹ), 7.24−7.20 (m, 3H, H-4ʹ, H-3ʹ & H-5ʹ), 6.96
6
(
d, J = 8.75 Hz, 1H, H-5), 6.95 (s, 2H, 2-NH ), 6.72 (dd, J = 8.75, 2.5 Hz, 1H, H-6), 6.67 (d, J =
2
2
1
.5 Hz, 1H, H-8), 4.81 (d, J = 2.5 Hz, 2H, 7-OCH C≡CH), 4.71 (s, 1H, H-4), 3.59 (t, J = 2.5 Hz,
2
1
3
H, 7-OCH C≡CH); C NMR (125 MHz, DMSO-d ), δ (ppm): 160.7 (C-2), 157.6 (C-7), 149.3
2
6
(C-8a), 146.8 (C-1ʹ), 130.5 (C-5), 129.1 (C-3ʹ & C-5ʹ), 127.9 (C-2ʹ & C-6ʹ), 127.2 (C-4ʹ), 121.1
1
7

ACCEPTED MANUSCRIPT
(
C≡N), 114.2 (C-4a), 112.9 (C-6), 102.7 (C-8), 79.4 (7-OCH C≡CH), 79.0 (7-OCH C≡CH), 56.6
2
2
(
C-3), 56.2 (7-OCH C≡CH), 40.5 (C-4); ESI/HRMS: calcd. for C H N O , M = 302.1055 Da;
2
19 14
2
2
+
found: m/z 302.1058 (100%) [M] ; Elemental anal., calcd: C, 75.48; H, 4.67; N, 9.27%; found: C,
75.77; H, 4.93; N, 9.07%.
4.1.2. 2-Amino-4-(4ʹ-nitrophenyl)-7-propargyloxy-4H-chromene-3-carbonitrile (5b)
Pale yellow crystals. From 4b (R = 4ʹ-NO , 1 mmol, 309 mg) and propargyl bromide (1.2 mmol,
2
1
1
1
5
43 mg, 0.2 mL of solution 80 wt.% in toluene). M.p. 289−290°C (from 96 % ethanol/toluene
–
1
:1); FT-IR (KBr), ν (cm ): 3445, 3402, 3342, 3267, 3083, 2971, 2865, 2179, 2117, 1657, 1615,
1
523, 1404, 1349; H NMR (500 MHz, DMSO-d ), δ (ppm): 8.11 (d, J = 7.5 Hz, 2H, H-3ʹ & H-
6
ʹ), 7.49 (d, J = 7.5 Hz, 2H, H-2ʹ & H-6ʹ), 7.23 (d, J = 7.5 Hz, 1H, H-5), 7.02 (s, 2H, 2-NH ), 6.73
2
(dd, J = 7.5, 1.5 Hz, 1H, H-6), 6.66 (d, J = 1.5 Hz, 1H, H-8), 4.88 (dd, J = 9.0, 3.0 Hz, 1H, 7-
(a)
(b)
OCH C≡CH), 4.87 (s, 1H, H-4), 4.82 (d, J = 9.0, 3.0 Hz, 1H, 7-OCH C≡CH), 3.60 (t, J = 3.0
2
2
1
3
Hz, 1H, 7-OCH C≡CH); C NMR (125 MHz, DMSO-d ), δ (ppm): 163.9 (C-2), 159.4 (C-7),
2
6
1
3
53.7 (C-8a), 146.8 (C-1ʹ), 146.5 (C-4ʹ), 146.5 (C-1ʹ), 129.3 (C-2ʹ & C-6ʹ), 127.1 (C-5), 123.6 (C-
ʹ & C-5ʹ), 120.6 (C≡N), 119.4 (C-4a), 111.6 (C-6), 102.2 (C-8), 79.0 (7-OCH C≡CH), 75.9 (7-
2
OCH C≡CH), 60.4 (C-3), 56.3 (7-OCH C≡CH), 44.0 (C-4); ESI/MS: calcd. for C H N O , M =
2
2
19 13
3
4
−
3
47.09 Da, M−H = 346.08 Da; found: m/z 346.07 [M−H] (100%).
4
.2. General procedures for click chemistry of substituted 2-amino-4-aryl-7-propargyloxy-4H-
-glucopyranosyl azide
Procedure A. Use of CuSO .5H O/sodium ascorbate for synthesis of 1H-1,2,3-triazole 7a (Entry
chromene-3-carbonitriles with tetra-O-acetyl-β-
D
4
2
1
, Table 3)
Reaction mixture consisted of 2-amino-4-phenyl-7-propargyloxy-4H-chromene-3-carbonitrile 5a
1 mmol, 302 mg) and tetra-O-acetyl-β- -glucopyranosyl azide 6 (1 mmol, 373 mg) in DMSO (5
mL). The mixture was stirred gently in order to dissolve the reactants. To the stirred reaction
(
D
1
8

ACCEPTED MANUSCRIPT
mixture distilled water (5 mL) was added dropwise. Then, CuSO .5H O (0.02 mmol, 5.0 mg) and
4
2
sodium ascorbate (0.05 mmol, 9,9 mg) were added successively to the reaction mixture at room
temperature. After stirring the reaction mixture for about 3−5 minutes at room temperature, some
white precipitate appeared. The reaction mixture was stirred overnight at room temperature and
poured into water (10 mL). The separated solids were filtered, washed with water and crystallized
from solvent mixture of 96% ethanol and toluene (ratio of 2:1 by volumes) to afford the titled
compounds 7a as white solids. Yield: 410 mg (60.7%).
Procedure B. Use of CuIm for synthesis of 1H-1,2,3-triazole 7a (Entry 2, Table 3)
2
Reaction mixture consisted of 2-amino-4-phenyl-7-propargyloxy-4H-chromene-3-carbonitrile 5a
(1 mmol, 302 mg) and azide 6 (1 mmol, 373 mg) in absolute ethanol (2 mL). Amount of used
catalyst CuIm (0.02 mmol, 3.99 mg) was added. The reaction mixture was heated under reflux at
2
70−75°C on bath for 90 min. Then, the reaction mixture was cooled to room temperature, toluene
(with half a volume) was added, the reaction mixture was heated to boiling, and the solid copper
catalysts were filtered out. The filtrate was left to stand overnight, and the product separated was
filtered and crystallized from solvent mixture of 96% ethanol and toluene (ratio of 2:1 by volumes)
to yield the compound 7a as white solids. Yield: 360 mg (53.3%).
Procedure C. Use of CuNPs for synthesis of 1H-1,2,3-triazole 7a (Entry 3, Table 3)
This procedure was performed similarly to Procedure B, but CuNPs was used as a catalyst, and
NEt was used as an additive. Reaction mixture consists of 2-amino-4-phenyl-7-propargyloxy-4H-
3
chromene-3-carbonitrile 5a (1 mmol, 302 mg) and azide 6 (1 mmol, 373 mg) and CuNPs (0.02
mmol, 34.8 mg) in t-BuOH (2 mL). Then, NEt (0.1 mL) was added in the stirring mixture. The
3
reaction mixture was heated and stirred under reflux at 85−87°C on bath for 30 min. After that, the
mixture was poured into water (10 mL), and the separated solids were filtered, washed with water
and crystallized from solvent mixture of 96% ethanol and toluene (ratio of 2:1 by volumes) to
1
9

ACCEPTED MANUSCRIPT
afford the compound 7a as white solids. Yield: 643 mg (95.2%).
Procedure D. Use of CuI for synthesis of 1H-1,2,3-triazole 7a (Entry 4, Table 3)
This procedure was performed similarly to Procedure B, but CuI was used as a catalyst. The
reaction mixture consisted of 2-amino-4-phenyl-7-propargyloxy-4H-chromene-3-carbonitrile 5a (1
mmol, 302 mg) and azide 6 (1 mmol, 373 mg) in a mixture of t-BuOH (2 mL) and water (0.1 mL).
Amount of catalyst CuI (0.02 mmol, 3.82 mg) was added. The reaction mixture was heated under
reflux at 85−87°C on bath for 1 h. Then, the reaction mixture was poured into water (10 mL), and
the separated solids were filtered, washed with water and crystallized from solvent mixture of 96%
ethanol and toluene (ratio of 2:1 by volumes) to afford compound 7a as white solids. Yield: 640
mg (94.8%).
Procedure E. Use of Cu@MOF-5 for synthesis of 1H-1,2,3-triazole 7a (Entries 5, Table 3)
This procedure was performed similarly to Procedure B, using Cu@MOF-5 as a catalyst. Reaction
mixture consists of 2-amino-4-phenyl-7-propargyloxy-4H-chromene-3-carbonitrile 5a (1 mmol)
and azide 6 (1 mmol) in absolute ethanol (2 mL). Amount of catalyst Cu@MOF-5 (0.02 mmol, 15
mg) was added. The reaction mixture was heated under reflux at 79−80°C on bath for 30 min.
Then, toluene (1 mL) was added to the reaction mixture, filtered off the solid catalyst, and the
filtrate was slowly cooled to give the product, recrystallized from solvent mixture of 96% ethanol
and toluene (ratio of 2:1 by volumes). Compound 7a was obtained with a yield of 97.8% (660 mg).
Because the procedure E gave the best yield, the other 1H-1,2,3-triazoles 7b-t were synthesized
using this procedure. The characterizations of these 1H-1,2,3-triazoles 7a-t are as follows.
4.2.1. 2-Amino-4-phenyl-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-1,2,3-triazol-
4-yl)methoxy)-4H-chromene-3-carbonitrile (7a)
Pale orange solids, from 5a (R = H; 1 mmol, 302 mg) and 6 (1 mmol, 373 mg). [α] ꢁꢀ ꢂ +90.1 (c =
2
0

ACCEPTED MANUSCRIPT
–
1
0
1
7
6
6
5
.22, CHCl ). FT-IR (KBr), ν (cm ): 3424, 3343, 3219, 3123, 2953, 2193, 1755, 1657, 1581,
3
1
506, 1456, 1375, 1224, 1155, 1101, 1039, 924; H NMR, δ (ppm): 8.55 (s, 1H, H-a), 7.32 (t, J =
.25 Hz, 2H, H-3′ & H-5′), 7.23 (t, J = 7.25 Hz, 1H, H-4′), 7.19 (d, J = 7.25 Hz, 2H, H-2′ & H-6′),
.95 (s, 2H, 2-NH ), 6.94 (d, J = 8.25 Hz, 1H, H-5), 6.75 (ddd, J = 8.25, 5.25, 2.75 Hz, 1H, H-6),
2
.71 (d, J = 2.0 Hz, 1H, H-8), 6.38 (d, J = 9.25 Hz, 1H, H-1′′), 5.68 (t, J = 9.25 Hz, 1H, H-2′′),
.57 (t, J = 9.25 Hz, 1H, H-3′′), 5.20 (t, J = 9.25 Hz, 1H, H-4′′), 5.17 (s, 2H, CH O), 4.70 (s, 1H,
2
H-4), 4.38 (ddd, J = 10.0, 5.5, 2.5 Hz, 1H, H-5′′), 4.12 (dd, J = 12.5, 5.5 Hz, 1H, H-6′′a), 4.08 (d, J
5.5 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.01 (s, 3H, 4-CH CO), 1.97 (s, 3H, 3-CH CO),
=
3
3
3
1
3
1
.76 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO), 170.0 (3-CH CO), 169.9 (4-
3 3 3
COCH ), 168.9 (2-CH CO), 160.7 (C-2), 158.0 (C-7), 149.3 (C-8a), 146.6 (C-1′), 143.7 (C-b),
3
3
1
1
4
30.5 (C-5), 129.1 (C-3′ & C-5′), 127.9 (C-2′ & C-6′), 127.2 (C-4′), 124.2 (C-a), 121.0 (C≡N),
16.4 (C-4a), 112.5 (C-6), 102.3 (C-8), 84.3 (C-1′′), 73.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-
′′), 62.3 (C-6′′), 61.7 (CH O), 56.6 (C-3), 39.5 (C-4), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7
2
3
3
(
3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for C H N O , M = 675.22 Da; found: m/z
3 3 33 33 5 11
+
+
6
76.13 (98%) [M+H] , 698.31 (100%) [M+Na] ; Elemental analysis, calcd: C, 58.66; H, 4.92; N,
10.37%; found: C, 58.79; H, 4.77; N, 10.52%.
4.2.2. 2-Amino-4-(4ʹ-nitrophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-1,2,3-
triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7b)
ꢁ
ꢂ
Pale yellow solids, from 5b (R = 4ʹ-NO ; 1 mmol, 347 mg) and 6 (1 mmol, 373 mg). [α] +86.2
2
ꢀ
–
1
(
c = 0.20, CHCl ). FT-IR (KBr), ν (cm ): 3470, 3285, 3143, 2958, 2931, 2192, 1756, 1651, 1614,
3
1
1
585, 1531, 1502, 1352, 1227, 1165, 1105, 1037, 924; H NMR, δ (ppm): 8.55 (s, 1H, H-a), 8.12
(
d, J = 7.5 Hz, 2H, H-3ʹ & H-5ʹ), 7.49 (d, J = 7.5 Hz, 2H, H-2ʹ & H-6ʹ), 7.03 (s, 2H, 2-NH ), 7.23
2
(d, J = 7.5 Hz, 1H, H-5), 6.73 (dd, J = 7.5, 1.5 Hz, 1H, H-6), 6.66 (d, J = 1.5 Hz, 1H, H-8), 6.37 (d,
J = 9.25 Hz, 1H, H-1′′), 5.67 (td, J = 9.25, 2.5 Hz, 1H, H-2′′), 5.56 (t, J = 9.5 Hz, 1H, H-3′′), 5.19
s, 2H, CH O), 4.97 (s, 1H, H-4), 4.38 (ddd, J = 9.75, 5.25, 2.5 Hz, 1H, H-5′′), 4.12 (dd, J = 5.5,
(
2
2
1

ACCEPTED MANUSCRIPT
1
.5 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5, 2.5 Hz, 1H, H-6′′a), 2.04 (s, 3H, 6-CH CO), 2.00 (s, 3H, 4-
3
13
CH CO), 1.98 (s, 3H, 3-CH CO), 1.75 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO),
3
3
3
3
170.0 (3-CH CO), 169.8 (4-CH CO), 168.9 (2-CH CO), 160.9 (C-2), 157.6 (C-7), 149.3 (C-8a),
3 3 3
148.4 (C-1ʹ), 146.8 (C-4ʹ), 146.5 (C-1ʹ), 143.7 (C-b), 130.5 (C-5), 129.3 (C-2ʹ & C-6ʹ), 124.2 (C-
a), 123.6 (C-3ʹ & C-5ʹ), 120.6 (C≡N), 115.4 (C-4a), 112.9 (C-6), 102.6 (C-8), 84.3 (C-1′′), 73.7 (C-
′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 55.7 (C-3), 39.5 (C-4), 21.0
5
2
(
6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for
3 3 3 3
+
+
C H N O , M = 720.20 Da; found: m/z 721.16 (30%) [M+H] , 743.25 (100%) [M+Na] ;
33
32
6
13
Elemental analysis, calcd: C, 55.00; H, 4.48; N, 11.66%; found: C, 55.23; H, 4.74; N, 11.82%.
4
.2.3. 2-Amino-4-(3ʹ-nitrophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-
triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7c)
Pale yellow solids, from 5c (R = 3ʹ-NO ; 1 mmol, 347 mg) and 6 (1 mmol, 373 mg). [α] +84.3
D-glucopyranosyl)-1H-1,2,3-
ꢁ
ꢂ
2
ꢀ
–
1
(
c = 0.28, CHCl ). FT-IR (KBr), ν (cm ): 3471, 3288, 3147, 2958, 2931, 2193, 1757, 1651, 1614,
3
1
1
587, 1531, 1502, 1352, 1227, 1165, 1105, 1037, 924; H NMR, δ (ppm): 8.55 (s, 1H, H-a), 8.11
(dd, J = 8.0, 1.5 Hz, 1H, H-4′), 8.07 (s, 1H, H-2′), 7.70 (dd, J = 8.0, 1.5 Hz, 1H, H-5′), 7.65 (td, J =
8
2
2
.9, 1.5 Hz, 1H, H-6′), 7.13 (s, 2H, 2-NH ), 6.99 (dd, J = 8.5, 2.5 Hz, 1H, H-5), 6.78 (dd, J = 8.5,
2
.5 Hz, 1H, H-6), 6.75 (d, J = 2.5 Hz, 1H, H-8), 6.37 (d, J = 9.25 Hz, 1H, H-1′′), 5.67 (td, J = 9.25,
.5 Hz, 1H, H-2′′), 5.56 (t, J = 9.5 Hz, 1H, H-3′′), 5.19 (s, 2H, CH O), 5.00 (s, 1H, H-4), 4.38 (ddd,
2
J = 9.75, 5.25, 2.5 Hz, 1H, H-5′′), 4.12 (dd, J = 5.5, 1.5 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5, 2.5 Hz,
1
2
H, H-6′′a), 2.04 (s, 3H, 6-CH CO), 2.00 (s, 3H, 4-CH CO), 1.98 (s, 3H, 3-CH CO), 1.75 (s, 3H,
3 3 3
13
-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO), 170.0 (3-CH CO), 169.8 (4-CH CO), 168.9
3
3
3
3
(
2-CH CO), 160.9 (C-2), 158.3 (C-7), 149.4 (C-8a), 148.8 (C-3′), 148.5 (C-1′), 143.7 (C-b), 134.8
3
(C-6′), 130.9 (C-5), 130.5 (C-2′), 124.2 (C-a), 122.4 (C-5′), 122.3 (C-4′), 120.7 (C≡N), 115.2 (C-
4a), 112.8 (C-6), 102.5 (C-8), 84.3 (C-1′′), 73.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3
(
C-6′′), 61.7 (CH O), 55.7 (C-3), 39.5 (C-4), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-
2
3
3
2
2

ACCEPTED MANUSCRIPT
CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for C H N O , M = 720.20 Da; found: m/z 721.14
3
3
33 32
6
13
+
+
(
30%) [M+H] , 743.27 (100%) [M+Na] ; Elemental analysis, calcd: C, 55.00; H, 4.48; N, 11.66%;
found: C, 55.33; H, 4.64; N, 11.86%.
4.2.4. 2-Amino-4-(2ʹ-nitrophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-1,2,3-
triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7d)
ꢁ
ꢂ
Pale yellow solids, from 5d (R = 2ʹ-NO ; 1 mmol, 347 mg) and 6 (1 mmol, 373 mg). [α] +90.1
2
ꢀ
–
1
(
c = 0.22, CHCl ). FT-IR (KBr), ν (cm ): 3472, 3288, 3147, 2958, 2931, 2194, 1755, 1651, 1614,
3
1
1
587, 1537, 1502, 1352, 1227, 1165, 1105, 1037, 924; H NMR, δ (ppm): 8.55 (s, 1H, H-a), 8.06
(dd, J = 7.5, 1.5 Hz, 1H, H-3′), 7.57 (td, J = 7.25, 1.25 Hz, 1H, H-5′), 7.48−7.45 (m, 2H, H-4′ &
H-6ʹ), 7.11 (s, 2H, 2-NH ), 7.01 (d, J = 8.0 Hz, 1H, H-5), 6.74 (dd, J = 8.5, 2.5 Hz, 1H, H-6), 6.71
2
(d, J = 2.5 Hz, 1H, H-8), 6.37 (d, J = 9.25 Hz, 1H, H-1′′), 5.67 (td, J = 9.25, 2.5 Hz, 1H, H-2′′),
5
.56 (t, J = 9.5 Hz, 1H, H-3′′), 5.19 (s, 2H, CH O), 4.92 (s, 1H, H-4), 4.38 (ddd, J = 9.75, 5.25, 2.5
2
Hz, 1H, H-5′′), 4.12 (dd, J = 5.5, 1.5 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5, 2.5 Hz, 1H, H-6′′a), 2.04
1
3
(
s, 3H, 6-CH CO), 2.00 (s, 3H, 4-CH CO), 1.98 (s, 3H, 3-CH CO), 1.75 (s, 3H, 2-CH CO); C
3 3 3 3
NMR, δ (ppm): 170.49 (6-CH CO), 170.02 (3-CH CO), 169.84 (4-CH CO), 168.90 (2-CH CO),
3
3
3
3
1
60.9 (C-2), 157.6 (C-7), 149.3 (C-8a), 147.9 (C-2ʹ), 143.7 (C-b), 135.5 (C-1ʹ), 132.4 (C-5ʹ), 130.5
C-5), 129.9 (C-6ʹ), 124.3 (C-3ʹ), 124.2 (C-a), 122.3 (C-6), 120.6 (C≡N), 115.4 (C-4a), 112.9 (C-
), 102.6 (C-8), 84.3 (C-1′′), 73.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7
CH O), 55.7 (C-3), 39.5 (C-4), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-
(
6
(
2
3
3
3
+
CH CO); ESI/MS, calcd for C H N O , M = 720.20 Da; found: m/z 721.18 (30%) [M+H] ,
3
33 32
6
13
+
7
43.25 (100%) [M+Na] ; Elemental analysis, calcd: C, 55.00; H, 4.48; N, 11.66%; found: C,
5.19; H, 4.75; N, 11.82%.
5
4.2.5. 2-Amino-4-(2ʹ,3ʹ-dichlorophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-
1H-1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7e)
2
3

ACCEPTED MANUSCRIPT
Dark orange solids, from 5e (R = 2ʹ,3ʹ-dichloro; 1 mmol, 371 mg), 6 (1 mmol, 373 mg). [α]ꢁ
ꢂ
ꢀ
–
1
+
92.5 (c = 0.24, CHCl ). FT-IR (KBr), ν (cm ): 3443, 3352, 3213, 3078, 2953, 2194, 1757, 1729,
3
1
1
651, 1622, 1585, 1507, 1398, 1250, 1234, 1157, 1041, 928; H NMR, δ (ppm): 8.55 (s, 1H, H-a),
.38 (dd, J = 7.5, 1.5 Hz, 1H, H-4′), 7.25 (t, J = 7.5 Hz, 1H, H-5′), 7.20−7.18 (m, 1H, H-6ʹ); 7.06
7
(
s, 2H, 2-NH ), 6.94 (d, 1H, J = 8.5 Hz, H-5), 6.72 (dd, 1H, J = 8.5, 2.5 Hz, H-6), 6.66 (d, 1H, J =
2
2.5 Hz, H-8), 6.38 (d, J = 9.25 Hz, 1H, H-1′′), 5.68 (d, J = 9.25 Hz, 1H, H-2′′), 5.58 (d, J = 9.25
Hz, 1H, H-3′′), 5.21−5.17 (m, 3H, H-4′′, CH O), 5.20 (s, 1H, H=4′′), 4.38 (ddd, J = 10.0, 5.5, 2.25
2
Hz, 1H, H-5′′), 4.13 (dd, J = 12.5, 5.5 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5, 2.25 Hz, 1H, H-6′′b),
2
.04 (s, 3H, 6-CH CO), 2.01 (s, 3H, 4-CH CO), 1.98 (s, 3H, 3-CH CO), 1.77 & 1.76 (s, 3H, 2-
3 3 3
13
CH CO); C NMR, δ (ppm): 170.5 (6-CH CO), 170.0 (3-CH CO), 169.9 (4-CH CO), 168.9 (2-
3
3
3
3
CH CO), 160.7 (C-2), 157.3 (C-7), 149.2 (C-8a), 143.6 (C-b), 142.4 (C-1ʹ), 132.1 (C-3ʹ), 131.1
3
(C-2ʹ), 130.5 (C-5), 129.7 (C-6ʹ), 129.4 (C-4ʹ), 127.7 (C-5ʹ), 120.8 (C≡N), 116.1 (C-4a), 112.8 (C-
6
7
4
), 102.4 (C-8), 124.2 (C-a), 120.5 (C≡N), 114.4 (C-4a), 112.7 (C-6), 102.4 (C-8), 84.3 (C-1′′),
3.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 54.8 (C-3), 37.4 (C-
2
), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for
3
3
3
3
C H Cl N O , M = 743.14/745.14/747.13 Da; found: m/z 742.21 (100%)/744.27 (61%)/746.28
33
31
2
5
11
+
(
14%) [M−H] ; Elemental analysis, calcd: C, 53.24; H, 4.20; N, 9.41%; found: C, 53.12; H, 4.47;
N, 9.64%.
4.2.6. 2-Amino-4-(2ʹ,4ʹ-dichlorophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-
1H-1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7f)
Dark orange solids, from 5f (R = 2ʹ,4ʹ-dichloro; 1 mmol, 371 mg), 6 (1 mmol, 373 mg). [α] ꢀꢁ ꢂ
–
1
+
88.2 (c = 0.22, CHCl ). FT-IR (KBr), ν (cm ): 3449, 3356, 3209, 3076, 2951, 2195, 1755, 1651,
3
1
1
620, 1583, 1506, 1468, 1402, 131, 1230, 1170, 1105, 1041, 926; H NMR, δ (ppm): 8.55 (s, 1H,
H-a), 7.61 (d, J = 1.5 Hz, 1H, H-3′), 7.42 (dt, J = 8.5, 2.75 Hz, 1H, H-6′), 7.26 (d, J = 8.5 Hz, 1H,
H-5′), 7.06 (s, 2H, 2-NH ), 6.86 (dd, J = 8.75, 2.25 Hz, 1H, H-5), 6.76 (dt, J = 8.75, 2.25 Hz, 1H,
2
2
4

ACCEPTED MANUSCRIPT
H-6), 6.72 (d, J = 2.25 Hz, 1H, H-8), 6.38 (d, J = 9.25 Hz, 1H, H-1′′), 5.68 (d, J = 9.25 Hz, 1H, H-
2
′′), 5.58 (d, J = 9.25 Hz, 1H, H-3′′), 5.21−5.17 (m, 3H, H-4′′, CH O), 5.20 (s, 1H, H=4′′), 4.38
2
(ddd, J = 10.0, 5.5, 2.25 Hz, 1H, H-5′′), 4.13 (dd, J = 12.5, 5.5 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5,
2
1
.25 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.01 (s, 3H, 4-CH CO), 1.98 (s, 3H, 3-CH CO),
3 3 3
1
3
.77 & 1.76 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO), 170.0 (3-CH CO), 169.9
3
3
3
(
4-CH CO), 168.9 (2-CH CO), 160.9 (C-2), 158.3 (C-7), 149.5 (C-8a), 143.6 (C-b), 142.1 (C-1′),
3 3
133.3 (C-2′), 132.8 (C-3′ & C-6′), 129.8 (C-5), 129.7 (C-4′), 128.6 (C-5′), 124.2 (C-a), 120.5
(C≡N), 114.4 (C-4a), 112.7 (C-6), 102.4 (C-8), 84.3 (C-1′′), 73.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′),
6
8.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 54.8 (C-3), 37.4 (C-4), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-
2
3
CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for C H Cl N O , M =
3
3
3
33 31
2
5
11
+
7
43.14/745.14/747.13 Da; found: m/z 742.19 (100%)/744.20 (63%)/746.24 (19%) [M−H] ;
Elemental analysis, calcd: C, 53.24; H, 4.20; N, 9.41%; found: C, 53.47; H, 4.39; N, 9.57%.
4.2.7. 2-Amino-4-(4ʹ-chlorophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-
1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7g)
White solids, from 5g (R = 4ʹ-Cl; 1 mmol, 337 mg) and 6 (1 mmol, 373 mg). [α] ꢁꢀ ꢂ +80.7 (c =
–
1
0
1
.25, CHCl ). FT-IR (KBr), ν (cm ): 3441, 3352, 3213, 3078, 2953, 2195, 1757, 1728, 1651,
3
1
620, 1582, 1506, 1398, 1250, 1234, 1157, 1041, 928; H NMR δ (ppm): 8.55 (d, J = 1.6 Hz, 1H,
H-a), 7.38 (d, J = 8.5 Hz, 2H, H-2′ & H-6′), 7.22 (d, J = 8.5 Hz, 2H, H-3′ & H-5′), 7.00 (s, 2H, 2-
NH ), 6.93 (dd, J = 8.5, 2.25 Hz, 1H, H-5), 6.76 (dt, J = 8.5, 2.25 Hz, 1H, H-6), 6.72 (s, 1H, H-8),
2
6
5
4
3
.38 (d, J = 9.25 Hz, 1H, H-1′′), 5.67 (d, J = 9.25 Hz, 1H, H-2′′), 5.57 (t, J = 9.25 Hz, 1H, H-3′′),
.20 (d, J = 9.8 Hz, 1H, H-4′′), 5.17 (s, 2H, CH O), 4.75 (s, 1H, H-4), 4.40–4.36 (m, 1H, H-5′′),
2
.13 (t, J = 8.9 Hz, 1H, H-6′′a), 4.08 (d, J = 10.9 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.01 (s,
3
1
3
H, 4-CH CO), 1.97 (s, 3H, 3-CH CO), 1.76 & 1.75 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5
3
3
3
(
6-CH CO), 170.0 (3-CH CO), 169.9 (4-CH CO), 168.9 (2-CH CO), 160.6 (C-2), 158.1 (C-7),
3 3 3 3
158.1 (C-1′), 149.3 (C-8a), 145.6 (C-4′), 143.7 (C-b), 131.8 (C-5), 130.5 (C-5), 129.8 (C-2′ & C-
2
5

ACCEPTED MANUSCRIPT
′), 129.1 (C-3 & C-5′), 124.2 (C-a), 120.9 (C≡N), 115.8 (C-4a), 112.6 (C-6), 102.4 (C-8), 84.3
6
(
C-1′′), 73.7 (C-5′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 56.2 (C-3),
2
3
9.5 (C-4), 21.0 (6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS,
3 3 3 3
calcd for C H ClN O , M = 709.18/711.18 Da; found: m/z 708.36 (100%)/710.39 (38%)
3
3
32
5
11
+
[
M−H] ; Elemental analysis, calcd: C, 55.82; H, 4.54; N, 9.86%; found: C, 55.66; H, 4.37; N,
9.65%.
4.2.8. 2-Amino-4-(3ʹ-chlorophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-
1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7h)
ꢁ
ꢂ
Pale yellow solids, from 5h (R = 3ʹ-Cl; 1 mmol, 337 mg) and 6 (1 mmol, 373 mg). [α] +76.4 (c
ꢀ
–
1
=
0.18, CHCl ). FT-IR (KBr), ν (cm ): 3429, 3344, 3215, 3132, 2947, 2895, 2195, 1757, 1730,
3
1
1
651, 1624, 1582, 1506, 1398, 1371, 1248, 1236, 1157, 1103, 1041, 928; H NMR, δ (ppm): 8.55
(s, 1H, H-a), 7.36 (td, J = 7.5, 1.5 Hz, 1H, H-5′), 7.30 (d, J = 7.5 Hz, 1H, H-4′), 7.24 (s, 1H, H-2′),
7
.17 (d, J = 7.5 Hz, 1H, H-6′), 7.04 (s, 2H, 2-NH ), 6.97 (dd, J = 8.75, 3.25 Hz, 1H, H-5), 6.77 (dt,
2
J = 8.75, 3.25 Hz, 1H, H-6), 6.72 (dd, J = 6.0, 2.5 Hz, 1H, H-8), 6.37 (d, J = 9.5 Hz, 1H, H-1′′),
.68 (td, J = 9.5, 1.5 Hz, 1H, H-2′′), 5.56 (t, J = 9.5 Hz, 1H, H-3′′), 5.20−5.18 (m, 3H, H-4′′ &
5
CH O), 4.77 (s, 1H, H-4), 4.38 (ddd, J = 10.0, 5.25, 2.25 Hz, 1H, H-5′′), 4.13 (dd, J = 12.25, 5.25
2
Hz, 1H, H-6′′a), 4.08 (dd, J = 12.25, 2.25 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.00 (s, 3H, 4-
3
13
CH CO), 1.97 (s, 3H, 3-CH CO), 1.74 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO),
3
3
3
3
170.0 (3-CH CO), 169.9 (4-CH CO), 168.9 (2-CH CO), 160.8 (C-2), 158.2 (C-7), 149.3 (C-8a),
3 3 3
149.1 (C-1′), 143.7 (C-b), 133.7 (C-3′), 131.1 (C-5′), 130.5 (C-5), 127.6 (C-2′), 127.3 (C-4′), 126.7
(C-6′), 124.2 (C-a), 120.8 (C≡N), 115.6 (C-4a), 112.7 (C-6), 102.4 (C-8), 84.3 (C-1′′), 73.7 (C-5′′),
7
2.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 56.0 (C-3), 39.5 (C-4), 21.0 (6ʹʹ-
2
CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (2-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for
3
3
3
3
−
C H ClN O , M = 709.18/711.18 Da; found: m/z 708.28 (100%)/ 710.27 (38%) [M−H] ;
33
32
5
11
Elemental analysis, calcd: C, 55.82; H, 4.54; N, 9.86%; found: C, 55.68; H, 4.72; N, 9.57%.
2
6

ACCEPTED MANUSCRIPT
4.2.9. 2-Amino-4-(2ʹ-chlorophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-
1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7i)
ꢁ
ꢂ
White solids, from 5i (R = 2ʹ-Cl; 1 mmol, 337 mg) and 6 (1 mmol, 373 mg). [α] +79.5 (c = 0.23,
ꢀ
–
1
CHCl ). FT-IR (KBr), ν (cm ): 3426, 3344, 3215, 3132, 2947, 2895, 2192, 1757, 1734, 1651,
3
1
1
624, 1582, 1506, 1398, 1371, 1248, 1236, 1157, 1103, 1045, 927; H NMR δ (ppm): 8.55 (d, J =
.6 Hz, 1H, H-a), 7.44 (dd, 1H, J = 1.5, 7.75 Hz, H-3ʹ), 7.32 (td, 1H, J = 7.5, 1.5 Hz, H-6ʹ), 7.27
1
(
td, 1H, J = 1.5, 7.5 Hz, H-4ʹ), 7.22 (dd, 1H, J = 7.5, 1.5 Hz, H-5ʹ), 7.00 (s, 2H, 2-NH ), 6.87 (d,
2
1
H, J = 8.5 Hz, H-5), 6.71 (dd, 1H, J = 8.5, 2.5 Hz, H-6), 6.67 (d, 1H, J = 2.5 Hz, H-8), 6.38 (d, J
9.25 Hz, 1H, H-1′′), 5.67 (d, J = 9.25 Hz, 1H, H-2′′), 5.57 (t, J = 9.25 Hz, 1H, H-3′′), 5.20 (d, J =
.8 Hz, 1H, H-4′′), 5.17 (s, 2H, CH O), 4.77 (s, 1H, H-4), 4.40–4.36 (m, 1H, H-5′′), 4.13 (t, J = 8.9
=
9
2
Hz, 1H, H-6′′a), 4.08 (d, J = 10.9 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.01 (s, 3H, 4-CH CO),
3
3
1
3
1
1
1
.97 (s, 3H, 3-CH CO), 1.76 & 1.75 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO),
3 3 3
70.0 (3-CH CO), 169.9 (4-CH CO), 168.9 (2-CH CO), 160.9 (C-2), 157.5 (C-7), 149.4 (C-8a),
3
3
3
43.7 (C-b), 143.0 (C-1ʹ), 132.3 (C-2ʹ), 130.3 (C-5), 129.8 (C-3ʹ), 129.2 (C-4ʹ), 128.4 (C-5ʹ), 124.2
(C-a), 120.6 (C≡N), 115.3 (C-4a), 112.7 (C-6), 102.4 (C-8), 84.3 (C-1′′), 73.7 (C-5′′), 72.6 (C-3′′),
7
0.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 56.2 (C-3), 39.5 (C-4), 21.0 (6ʹʹ-CH CO), 20.9
2
3
(
4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for C H ClN O , M =
3 3 3 33 32 5 11
−
7
09.18/711.18 Da; found: m/z 708.25 (100%)/ 710.22 (35%) [M−H] ; Elemental analysis, calcd:
C, 55.82; H, 4.54; N, 9.86%; found: C, 55.67; H, 4.74; N, 9.68%.
4.2.10. 2-Amino-4-(4ʹ-bromophenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-
1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7j)
ꢁ
ꢂ
White solids, from 5j (R = 4ʹ-Br; 1 mmol, 381 mg) and 6 (1 mmol, 373 mg). [α] +77.5 (c = 0.23,
ꢀ
–
1
CHCl ). FT-IR (KBr), ν (cm ): 3442, 3353, 3213, 3078, 2953, 2193, 1756, 1728, 1654, 1620,
3
1
1
582, 1506, 1398, 1251, 1234, 1157, 1041, 928; H NMR δ (ppm): 8.55 (d, J = 1.6 Hz, 1H, H-a),
2
7

ACCEPTED MANUSCRIPT
7
6
6
5
4
3
.38 (d, 2H, J = 8.5 Hz, H-2ʹ & H-6ʹ), 7.22 (d, 2H, J = 8.5 Hz, H-3ʹ & H-5ʹ), 6.99 (s, 2H, 2-NH ),
2
.94 (d, 1H, J = 8.5 Hz, H-5), 6.72 (dd, 1H, J = 8.5, 2.5 Hz, H-6), 6.66 (d, 1H, J = 2.5 Hz, H-8),
.38 (d, J = 9.25 Hz, 1H, H-1′′), 5.67 (d, J = 9.25 Hz, 1H, H-2′′), 5.57 (t, J = 9.25 Hz, 1H, H-3′′),
.20 (d, J = 9.8 Hz, 1H, H-4′′), 5.17 (s, 2H, CH O), 4.75 (s, 1H, H-4), 4.40–4.36 (m, 1H, H-5′′),
2
.13 (t, J = 8.9 Hz, 1H, H-6′′a), 4.08 (d, J = 10.9 Hz, 1H, H-6′′b), 2.04 (s, 3H, 6-CH CO), 2.01 (s,
3
1
3
H, 4-CH CO), 1.97 (s, 3H, 3-CH CO), 1.76 & 1.75 (s, 3H, 2-CH CO); C NMR, δ (ppm): 170.5
3
3
3
(
6-CH CO), 170.0 (3-CH CO), 169.9 (4-CH CO), 168.9 (2-CH CO), 160.7 (C-2), 157.3 (C-7),
3 3 3 3
1
49.2 (C-8a), 145.5 (C-1ʹ), 143.7 (C-b), 131.9 (C-4ʹ), 130.5 (C-5), 129.8 (C-2ʹ & C-6ʹ), 129.1 (C-3ʹ
C-5ʹ), 124.2 (C-a), 120.8 (C≡N), 116.1 (C-4a), 112.8 (C-6), 102.4 (C-8), 84.3 (C-1′′), 73.7 (C-
′′), 72.6 (C-3′′), 70.6 (C-2′′), 68.0 (C-4′′), 62.3 (C-6′′), 61.7 (CH O), 56.2 (C-3), 39.5 (C-4), 21.0
&
5
2
(
6ʹʹ-CH CO), 20.9 (4ʹʹ-CH CO), 20.7 (3ʹʹ-CH CO), 20.3 (2ʹʹ-CH CO); ESI/MS, calcd for
3 3 3 3
−
C H BrN O , M = 753.13/755.13 Da; found: m/z 752.22 (100%)/754.21 (96%) [M−H] ;
33
32
5
11
Elemental analysis, calcd: C, 52.53; H, 4.27; N, 9.28%; found: C, 52.74; H, 4.51; N, 9.43%.
4.2.11. 2-Amino-4-(4ʹ-methylphenyl)-7-((1-(2ʹʹ,3ʹʹ,4ʹʹ,6ʹʹ-tetra-O-acetyl-β-D-glucopyranosyl)-1H-
1,2,3-triazol-4-yl)methoxy)-4H-chromene-3-carbonitrile (7k)
White solids, from 5k (R = 4ʹ-Me; 1 mmol, 316 mg) and 6 (1 mmol, 373 mg). [α] ꢁꢀ ꢂ +89.3 (c =
–
1
0
1
.25, CHCl ). FT-IR (KBr), ν (cm ): 3441, 3352, 3213, 3123, 3003, 2953, 2193, 1757, 1730,
3
1
651, 1622, 1582, 1506, 1398, 1248, 1234, 1157, 1123, 1041, 928; H NMR, δ (ppm): 8.55 (s, 1H,
H-a), 7.12 (d, J = 7.75 Hz, 2H, H-2′ & H-6′), 7.07 (d, J = 7.75 Hz, 2H, H-3′ & H-5′), 6.92 (d, J =
.0 Hz, 1H, H-5), 6.91 (s, 2H, 2-NH ), 6.76−6.73 (m, 1H, H-6), 6.70 (d, J = 2.5 Hz, 1H, H-8), 6.38
3
2
(d, J = 9.25 Hz, 1H, H-1′′), 5.68 (t, J = 9.25 Hz, 1H, H-2′′), 5.57 (t, J = 9.25 Hz, 1H, H-3′′), 5.20
(
d, J = 9.25 Hz, 1H, H-4′′), 5.16 (s, 2H, CH O), 4.64 (s, 1H, H-4), 4.38 (ddd, J = 10.0, 5.25, 2.25
2
Hz, 2H), 4.12 (dd, J = 12.5, 5.25 Hz, 1H, H-6′′a), 4.08 (dd, J = 12.5, 2.25 Hz, 1H, H-6′′b), 2.26 (s,
3
2
H, 4′-CH ), 2.04 (s, 3H, 6-CH CO), 2.01 (s, 3H, 4-CH CO), 1.98 (s, 3H, 3-CH CO), 1.76 (s, 3H,
3 3 3 3
13
-CH CO); C NMR, δ (ppm): 170.5 (6-CH CO), 170.0 (3-CH CO), 169.9 (4-CH CO), 168.9
3
3
3
3
2
8