Ultrasound assisted synthesis of coumarin thioglycopyranoside derivatives

Article abstract of DOI:10.1002/jccs.200900169

Themethyl coumarins reacted with N-bromo-succinimide gave compounds (a～c) which on further reacted with various peracetyl sulfhydryl glycose (1～3) afforded a series of novel coumarin thioglycopyranoside compounds (1a～1c, 2a～2c, 3a～3c). And when used ultra

Full text of DOI:10.1002/jccs.200900169

Journal of the Chinese Chemical Society, 2009, 56, 1175-1179
1175
Ultrasound Assisted Synthesis of Coumarin Thioglycopyranoside
Derivatives
Lei Yu (
College of Chemistry and Engineering, Xinjiang University, Urumqi 830046, P. R. China
), Jian-Fang Gao (
) and Ling-Hua Cao* (
)
The methyl coumarins reacted with N-bromo-succinimide gave compounds (a~c) which on further re-
acted with various peracetyl sulfhydryl glycose (1~3) afforded a series of novel coumarin thioglycopy-
ranoside compounds (1a~1c, 2a~2c, 3a~3c). And when used ultrasonic irradiation, this method offered
several advantages such as good yields and short reaction time than the silent reaction. All the new com-
pounds were characterized on the basis of the IR, 1H NMR, 13C NMR and elemental analysis.
Keywords: Coumarin; Thioglycopyranoside; Ultrasonic; Synthesis.
INTRODUCTION
Ultrasound irradiation has been increasingly used in
In view of this, we design and synthesize a series of
novel coumarin thioglycopyranoside derivatives with the
aim of finding novel coumarin derivatives with more excel-
lent properties. Synthesized routes are shown in Scheme I.
The structures of the new compounds were deduced based
on IR, 1H NMR spectroscopy and elemental analysis, and
all compounds were found to take the b-configuration.11-13
organic synthesis in last three decades. A large number of
organic reactions can be carried out in higher yield, shorter
reaction time and milder conditions under ultrasonic irradi-
ation.1 As a part of our interest in the synthesis of thiogly-
copyranoside derivatives, our current research program is
concerned with utility of peracetyl sulfhydryl glycose in
the synthesis of several new thioglycosylation of biological
active compounds such as quinazolinone.
EXPERIMENTAL
General instrumentation procedures
1
In recent years, coumarin derivatives have received
significant attention owing to their diverse range of biolog-
ical properties such as anti-viral, anticoagulant,2 antibacte-
rial,3 antifungal,4 anti-HIV5 and antihistamine6 actions. Be-
sides the wide biological applications of coumarin and its
derivatives the chemical literature also embodies their
some applications from the material view point such as cos-
metics, optical brightening agents, dispersed fluorescent
and laser dyes.7 In addition, some coumarins are of interest
because of their toxicity, carcinogenity and photodynamic
effects.8
The H and 13C NMR spectra were recorded on an
INOVA-400 NMR spectrometer, using CDCl3 as solvent
and TMS as internal reference (chemical shifts in d). The
IR spectra were recorded as KBr pellets on a Bruker Equi-
nox 55 FT-IR spectrophotometer. Melting points were
measured on a Yanaco MP-S3 melting point apparatus and
are uncorrected. Elemental analyses were performed on a
Thermo Flash EA1112 elemental analyzer. Analytical thin-
layer chromatography (TLC) was performed on silica gel
GF254 (Qingdao, China) with EtOAc and light petroleum
(fraction boiling in the range of 60-90 °C) and detection by
UV light or iodine vapor. Sonication was performed by
Fisher sonicator (with a frequency of 25 kHz and a nominal
power 600 W). All reagents were commercial products of
analytical grade and were used directly without processing
unless otherwise specified.
Thioglycosides as an important tool have an essential
place in carbohydrate chemistry and carbohydrate biology.
Such compounds have been exploited as glycosyl donors,
enzyme inhibitors, and synthetic vaccines.9 They have re-
ceived considerable attention because of their resistance to
enzymatic hydrolysis and biological activities compared to
native counterparts which native O-glycosidic linkage has
been replaced by the enzymatically and chemically more
resistant S-glycosidic linkage.10
General procedure
Synthesis of intermediates
Peracetyl sulfhydryl glycose (1~3) were prepared ac-
cording to the reported14,15 method. The synthesis and char-
* Corresponding author. E-mail: clhxj@xju.edu.cn

1176 J. Chin. Chem. Soc., Vol. 56, No. 6, 2009
Yu et al.
Scheme I
acterization of bromomethyl-coumarin derivatives (a~c)
were reported elsewhere.1
Table 1. The reaction time and yield of silent reaction and
sonicated reactions
Synthesis of the target compounds
Silent reactions
Sonicated reactions
Compd.
Silent reactions: 1 mmol peracetyl sulfhydryl glycose
(1~3), 1 mmol bromomethyl-coumarin derivatives (a~c), 1
g anhydrous K2CO3 and 20 mL acetone were mixed thor-
oughly with stirring under reflux. After the completion of
reaction as indicated by TLC (EtOAc-petroleum ether =
1:1), the reaction residue was filtered off and the solvent
was evaporated under reduced pressure to afford crude
product. Then the pure product was gotten by recrystallized
from ethanol-water. Reaction time and yield were listed in
Table 1.
Reaction time
(min)
Yield
Reaction time
(min)
Yield
(%)
(%)
1a
1b
1c
2a
2b
2c
3a
3b
3c
120
120
120
90
31.3
64.0
26.2
25.1
30.9
26.2
44.2
68.7
65.6
15
15
15
15
15
15
20
20
20
53.0
72.0
62.7
46.6
51.2
48.9
66.3
76.5
73.3
90
90
140
140
140
Sonicated reactions: 1 mmol bromomethyl-coumarin
derivatives (a~c) which was dissolved in 20 mL acetone
beforehand, 1 mmol peracetyl sulfhydryl glycose (1~3) and
1 g anhydrous K2CO3 were mixed thoroughly. The mixture
was subjected to ultrasound irradiation at room tempera-
ture. After the completion of reaction as indicated by TLC
(EtOAc-petroleum ether = 1:1), the reaction residue was
filtered off and the filtrate was evaporated under reduced
pressure to afford crude product. Then the pure product
was got by recrystallized from ethanol-water. The melting
point and crystal form of the compounds were according to
the compounds of silent reactions. Reaction time and yield
were listed in Table 1.
7¢-Methylene-coumarinyl-2,3,4,6-tetra-O-acetyl-1-thio-
b-D-glucopyraoside (1a)
White solid, yield: 53.0%, m.p. 84~86 °C; 1H NMR
(CDCl3, 400 MHz) d: 2.01, 2.03, 2.04, 2.14 (4s, 12H, 4 ×
COCH3), 3.50~3.58 (m, 1H, sugar ring-H), 3.86 (d, J =
13.2 Hz, 1H, SCHa), 3.99 (d, J = 13.2 Hz, 1H, SCHb),

Ultrasound Assisted Synthesis of Thioglycopyranosides
J. Chin. Chem. Soc., Vol. 56, No. 6, 2009 1177
4.12~5.15 (m, 5H, sugar ring-H), 5.16 (d, J = 9.6 Hz, 1H,
C1-H), 6.26 (s, 1H, 3¢-H), 7.26~7.58 (m, 4H, coumarin H).
13C NMR (100 MHz, CDCl3): d 170.7, 170.6, 170.3, 170.0,
169.6, 160.1, 153.4, 146.6, 131.5, 125.5, 119.2, 117.4,
113.4, 81.5, 77.6, 76.0, 73.8, 70.6, 67.8, 62.6, 21.0, 20.9,
20.5, 19.2. IR (KBr) n: 1742 (s, CH3C=O), 1720 (ester
C=O), 1033 (s, C-O), 896 (m, C1-H) cm-1. Anal. Calcd for
C24H26O11S: C, 55.17; H, 5.02. Found: C, 55.26; H, 5.04.
7¢-Methylene-4¢-methylcoumarinyl-2,3,4,6-tetra-O-
acetyl-1-thio-b-D-glucopyraoside (1b)
125.7, 119.0, 117.5, 113.7, 80.5, 75.6, 72.5, 69.4, 67.8,
62.9, 21.0, 20.9, 20.5. IR (KBr) n: 1738 (s, CH3C=O), 1722
(ester C=O), 1039 (s, C-O), 899 (m, C1-H) cm-1. Anal.
Calcd for C21H22O9S: C, 55.99; H, 4.92. Found: C, 56.03;
H, 4.90.
7¢-Methylene-4¢-methylcoumarinyl-2,3,4-tri-O-acetyl-1-
thio-b-D-xylopyranoside (2b)
White acicular crystals, yield: 51.2%, m.p. 126~127
°C; 1H NMR (CDCl3, 400 MHz) d: 2.02, 2.09, 2.15 (3s, 9H,
3 ´ COCH3), 4.90~5.20 (m, 5H, sugar ring-H), 4.68 (d, J =
9.2 Hz, 1H, C1-H), 3.87 (d, J = 13.2 Hz, 1H, SCHa), 3.98
(d, J = 13.2 Hz, 1H, SCHb), 6.32 (s, 1H, 3¢-H), 7.26~7.59
(m, 4H, Coumarin H). 13C NMR (100 MHz, CDCl3): d
170.7, 170.3, 170.0, 169.4, 160.9, 153.6, 152.3, 141.5,
125.0, 119.4, 117.1, 115.5, 80.7, 75.5, 72.3, 69.9, 68.2,
62.6, 32.9, 20.9, 20.7, 20.5. IR (KBr) n: 1736 (s, CH3C=O),
1720 (ester C=O), 1038 (s, C-O), 903 (m, C1-H) cm-1.
Anal. Calcd for C22H24O9S: C, 56.89; H, 5.21. Found: C,
56.78; H, 5.23.
1
White powder, yield: 72.0%, m.p. 76~78 °C; H
NMR (CDCl3, 400 MHz) d: 2.00, 2.03, 2.04, 2.15 (4s, 12H,
4 × COCH3), 2.45 (s, 3H, 4¢-CH3), 3.61~3.65 (m, 1H,
sugar ring-H), 3.86 (d, J = 13.2 Hz, 1H, SCHa), 3.99 (d, J =
13.2 Hz, 1H, SCHb), 4.13~5.13 (m, 5H, sugar ring-H), 5.17
(d, J = 9.2 Hz, 1H, C1-H), 6.30 (s, 1H, 3¢-H), 7.26~7.58 (m,
3H, Coumarin H). 13C NMR (100 MHz, CDCl3): d 170.6,
170.5, 170.1, 169.5, 169.4, 160.6, 153.6, 152.0, 141.6,
124.9, 119.2, 117.4, 115.1, 81.6, 76.7, 76.0, 73.7, 69.7,
68.2, 62.2, 33.1, 20.8, 20.7, 20.6, 18.7. IR (KBr) n: 1756 (s,
CH3C=O), 1728 (ester C=O), 1227 (s, CH3C=O), 1143 (s,
C-O-C), 1037 (s, Coumarin C-O), 913 (m, C1-H) cm-1.
Anal. Calcd for C25H28O11S: C, 55.96; H, 5.26. Found: C,
56.07; H, 5.28.
6¢-Methylene-4¢-methylcoumarinyl-2,3,4-tri-O-acetyl-1-
thio-b-D-xylopyranoside (2c)
1
White powder, yield: 48.9%, m.p. 137~139 °C; H
NMR (CDCl3, 400 MHz) d: 2.02, 2.05, 2.08, (3s, 9H, 3 ×
COCH3), 2.47 (s, 3H, 4¢-CH3), 3.85 (d, J = 13.2 Hz, 1H,
SCHa), 3.97 (d, J = 13.2 Hz, 1H, SCHb), 4.94~5.20 (m, 5H,
sugar ring-H), 4.61 (d, J = 9.2 Hz, 1H, C1-H), 6.30 (s, 1H,
3¢-H), 7.28~7.61 (m, 3H, Coumarin H). 13C NMR (100
MHz, CDCl3): d 170.8, 170.4, 169.8, 169.5, 159.9, 153.5,
149.6, 140.8, 124.1, 122.8, 120.4, 115.6, 80.9, 75.5, 72.8,
69.4, 66.8, 62.8, 33.1, 21.0, 20.9, 20.7. IR (KBr) n: 1738 (s,
CH3C=O), 1721 (ester C=O), 1032 (s, C-O), 893 (m,
C1-H) cm-1. Anal. Calcd for C22H24O9S: C, 56.89; H, 5.21.
Found: C, 56.84; H, 5.23.
6¢-Methylene-4¢-methylcoumarinyl-2,3,4,6-tetra-O-
acetyl-1-thio-b-D-glucopyraoside (1c)
1
White powder, yield: 62.7%, m.p. 137~139 °C; H
NMR (CDCl3, 400 MHz) d: 2.00, 2.01, 2.03, 2.15 (4s, 12H,
4 × COCH3), 2.47 (s, 3H, 6¢-CH3), 3.59~3.64 (m, 1H, sugar
ring-H), 3.86 (d, J = 13.2 Hz, 1H, SCHa), 3.99 (d, J = 13.2
Hz, 1H, SCHb), 5.17 (d, J = 9.6 Hz, 1H, C1-H), 6.30 (s, 1H,
3¢-H), 7.27~7.60 (m, 3H, Coumarin H). 13C NMR (100
MHz, CDCl3): d 170.7, 170.3, 169.7, 169.4, 169.0, 159.5,
153.9, 149.7, 141.4, 124.0, 122.3, 120.7, 115.4, 81.7, 76.9,
76.0, 73.8, 70.4, 68.7, 63.3, 33.0, 20.9, 20.8, 20.6, 19.9. IR
(KBr) n: 1740 (s, CH3C=O), 1724 (ester C=O), 1030 (s,
C-O), 897 (m, C1-H) cm-1. Anal. Calcd for C25H28O11S: C,
55.96; H, 5.26. Found: C, 55.05; H, 5.24.
7¢¢-Methylene-coumarinyl-2,3,6,2¢,3¢,4¢,6¢-hepta-O-
acetyl-1-thio-b-lactoside (3a)
White powder, yield: 66.3%, m.p. 176.5~178 °C; 1H
NMR (CDCl3, 400 MHz) d: 1.96, 2.03, 2.03, 2.06, 2.06,
2.15, 2.18 (7s, 21H, 7 × COCH3), 5.36 (d, J = 9.2 Hz, 1H,
C1-H), 5.87 (d, J = 9.4 Hz, 1H, C¢1-H), 3.83 (d, J = 13.2
Hz, 1H, SCHa), 3.96 (d, J = 13.2 Hz, 1H, SCHb), 3.70~5.18
(m, 12H, sugar ring-H), 6.44 (s, 1H, 3¢-H), 7.20~7.76 (m,
4H, Coumarin H). 13C NMR (100 MHz, CDCl3): d 170.9,
170.8, 170.6, 170.5, 170.2, 169.7, 169.5, 169.0, 159.8,
153.3, 149.2, 140.7, 124.0, 122.5, 120.2, 115.3, 104.5,
82.1, 77.5, 76.8, 73.5, 73.3, 72.4, 72.1, 70.8, 70.4, 68.9,
68.6, 62.6, 21.0, 20.9, 20.7, 20.4, 20.3, 19.8, 19.6. IR (KBr)
n: 1745 (s, CH3C=O), 1720 (ester C=O), 1032 (s, C-O),
7¢-Methylene-coumarinyl-2,3,4-tri-O-acetyl-1-thio-b-D-
xylopyranoside (2a)
White acicular crystals, yield: 46.6%, m.p. 159~160
°C; 1H NMR (CDCl3, 400 MHz) d: 2.03, 2.08, 2.12 (3s, 9H,
3 ´ COCH3), 4.92~5.20 (m, 5H, sugar ring-H), 4.69 (d, J =
9.2 Hz, 1H, C1-H), 3.85 (d, J = 13.2 Hz, 1H, SCHa), 3.97
(d, J = 13.2 Hz, 1H, SCHb), 6.30 (s, 1H, 3¢-H), 7.26~7.58
(m, 4H, Coumarin H). 13C NMR (100 MHz, CDCl3): d
170.9, 170.7, 170.4, 169.7, 160.2, 153.6, 146.5, 131.4,

1178 J. Chin. Chem. Soc., Vol. 56, No. 6, 2009
Yu et al.
901 (m, C1-H) cm-1. Anal. Calcd for C36H42O19S: C, 53.33;
H, 5.22. Found: C, 53.41; H, 5.20.
place.
It was observed that the reaction time decreased con-
siderably and the yields of the products promoted in the
presence of ultrasonic irradiation, especially the compounds
1a and 1c, and their yields increased by 21.7% and 36.5%
respectively. Thus, ultrasonic irradiation was found to have
beneficial effect on the synthesis of thioglycopyranoside.
It was worth noting that a sum of coumarin ring opened
and undesired by-products such as chromones are formed
under the basic condition and heating.16 Thus, the proposed
reason for higher yield was the coumarin ring possibly
could keep. Because of the short reaction time and without
heating, most of the coumarin ring didn’t open under ultra-
sonic irradiation.
7¢¢-Methylene-4¢¢-methylcoumarinyl-2,3,6,2¢,3¢,4¢,6¢-
hepta-O-acetyl-1-thio-b-lactoside (3b)
1
White powder, yield: 76.5%, m.p. 149~152 °C; H
NMR (CDCl3, 400 MHz) d: 1.97, 2.00, 2.03, 2.03 ,2.04,
2.04, 2.15 (7s, 21H, 7 × COCH3), 2.49 (s, 3H, 4¢-CH3),
3.60~3.65 (m, 1H, sugar ring-H), 3.83 (d, J = 13.2 Hz, 1H,
SCHa), 3.96 (d, J = 13.2 Hz, 1H, SCHb), 5.35 (d, J = 9.2 Hz,
1H, C1-H), 5.88 (d, J = 9.4 Hz, 1H, C¢1-H), 4.15~5.19 (m,
12H, sugar ring-H), 6.32 (s, 1H, 3¢-H), 7.26~7.58 (m, 3H,
Coumarin H). 13C NMR (100 MHz, CDCl3): d 170.8,
170.7, 170.6, 170.5, 170.3, 169.6, 169.5, 169.2, 160.7,
153.5, 152.2, 141.7, 125.3, 119.7, 117.4, 115.2, 104.7,
82.3, 77.8, 76.4, 73.4, 73.0, 72.5, 72.4, 70.6, 70.4, 68.8,
68.4, 62.8, 33.0, 21.0, 20.8, 20.7, 20.5, 20.3, 19.8, 19.7. IR
(KBr) n: 1744 (s, CH3C=O), 1723 (ester C=O), 1036 (s,
C-O), 898 (m, C1-H) cm-1. Anal. Calcd for C37H44O19S: C,
53.88; H, 5.38. Found: C, 53.79; H, 5.36.
In the IR spectra the compounds 3a~3c, 4a~4c and
5a~5c exhibited C=O of the ring of sugar stretching fre-
quency around 1750 cm-1 and the C=O of lactone in the re-
gion around 1720 cm-1. All compounds were found to take
the b-configuration due to the C1-H linkages appeared
around 901 cm-1.12
6¢¢-Methylene-4¢¢-coumarinyl-2,3,6,2¢,3¢,4¢,6¢-hepta-O-
acetyl-1-thio-b-lactoside (3c)
1
The H NMR of the products of 3a~3c, 4a~4c and
1
White powder, yield: 73.3%, m.p. 98~99 °C; H
5a~5c showed several singlet around d 2.0 corresponding
to the protons of acetyl of sugar. Take 3a for example, the
1H NMR also showed the presence of two doublets at d
3.86 an 3.99 for the protons at the metheneyl because the
two protons are chemical inequivalence with coupling con-
stant J = 13.2 Hz. The protons of sugar-ring appeared at the
region of d 4.13 to d 4.66. C1-H proton appeared as doublet
as a result of C2-H coupling, and their 3J = 9.2 Hz proved
the compound take the b-configuration once again (The
data J = 8-10 Hz further indicated the b-anomer).13
In the 13C NMR, the carbonyl signal of lactone ring in
coumarin is at about d 169 which is lower than acetyl in
sugar ring. C1 signal in sugar ring is also higher than oth-
ers, and the signal of sugar appeared at d 65-85. However,
the chemical shift of C1¢ in lactosyl is about d 104 because
of the induced effect of oxygen atom. The signal of meth-
eneyl in coumarin appeared at d 62-63, and aryl carbon sig-
nal appeared at ca. d 165-110.
NMR (CDCl3, 400 MHz) d: 1.99, 2.01, 2.01, 2.93, 2.03,
2.04, 2.13 (7s, 21H, 7 × COCH3), 2.43 (s, 3H, 4¢-CH3),
3.51~3.57 (m, 1H, sugar ring-H), 3.83 (d, J = 13.2 Hz, 1H,
SCHa), 3.96 (d, J = 13.2 Hz, 1H, SCHb), 3.73~5.19 (m,
12H, sugar ring-H), 5.35 (d, J = 9.6 Hz, 1H, C1-H), 5.88 (d,
J = 9.4 Hz, 1H, C¢1-H), 6.28 (s, 1H, 3¢-H), 7.26~7.58 (m,
3H, Coumarin H). 13C NMR (100 MHz, CDCl3): d 170.9,
170.7, 170.6, 170.4, 170.2, 169.9, 169.6, 169.4, 160.2,
153.4, 149.7, 140.3, 124.3, 122.5, 120.2, 115.8, 104.9,
82.6, 77.4, 76.6, 73.5, 73.2, 72.6, 72.4, 70.7, 70.5, 68.6,
68.5, 62.6, 33.1, 20.9, 20.7, 20.6, 20.4, 20.3, 19.9, 19.8. IR
(KBr) n: 1746 (s, CH3C=O), 1722 (ester C=O), 1035 (s,
C-O), 902 (m, C1-H) cm-1. Anal. Calcd for C37H44O19S: C,
53.88; H, 5.38. Found: C, 53.97; H, 5.40.
RESULTS AND DISCUSSION
1-Thioglycopyranoside were usually synthesized
through sulfur glycosylation reaction or using nucleophilic
substitution of mercaptan anion. The compounds 1a~1c,
2a~2c and 3a~3c were synthesized through replaced reac-
tion of 1-deox-1-thiogluose (3, 4, 5) and bromomethyl
coumarin. In addition, when synthesis the target compounds
under ultrasonic irradiation, the bromomethyl coumarin
must be dissolved in the acetone completely beforehand,
otherwise, the nucleophilic substitution reaction won’t take
ACKNOWLEDGEMENT
This work was supported by the National Natural Sci-
ence Foundation of China (Grant No. 20462006) and Xin-
jiang Key Laboratory of Plant Resources & Natural Prod-
ucts Chemistry.
Received April 2, 2009.

Ultrasound Assisted Synthesis of Thioglycopyranosides
J. Chin. Chem. Soc., Vol. 56, No. 6, 2009 1179
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