S-glycosides in medicinal chemistry: Novel synthesis of cyanoethylene thioglycosides and their pyrazole derivatives

Article abstract of DOI:10.1080/15257770.2016.1257807

A one-pot reaction of a sodium 2-cyanoethylene-1-thiolate salt with 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl bromides affords a new class of cyanoethylene thioglycosides. The conversion to the corresponding 5-aminopyrazoles confirms the E-co

Full text of DOI:10.1080/15257770.2016.1257807

Nucleosides, Nucleotides and Nucleic Acids
ISSN: 1525-7770 (Print) 1532-2335 (Online) Journal homepage: http://www.tandfonline.com/loi/lncn20
S-Glycosides in Medicinal Chemistry: Novel
Synthesis of Cyanoethylene Thioglycosides and
Their Pyrazole Derivatives
Galal Elgemeie, Nahed Fathy, Wafaa Zaghary & Ayman Farag
To cite this article: Galal Elgemeie, Nahed Fathy, Wafaa Zaghary & Ayman Farag (2017):
S-Glycosides in Medicinal Chemistry: Novel Synthesis of Cyanoethylene Thioglycosides
and Their Pyrazole Derivatives, Nucleosides, Nucleotides and Nucleic Acids, DOI:
10.1080/15257770.2016.1257807
To link to this article: http://dx.doi.org/10.1080/15257770.2016.1257807
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Date: 10 January 2017, At: 05:20

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
, VOL. , NO. , –
http://dx.doi.org/./..
S-Glycosides in Medicinal Chemistry: Novel Synthesis of
Cyanoethylene Thioglycosides and Their Pyrazole
Derivatives
Galal Elgemeiea, Nahed Fathyb, Wafaa Zagharyc, and Ayman Faragd
aChemistry Department, Faculty of Science, Helwan University, Helwan, Cairo, Egypt; bPhotochemistry
Department, National Research Centre, Dokki, Cairo, Egypt; cPharmaceutical Chemistry Department,
Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt; dPharmaceutical Chemistry Department,
Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
ABSTRACT
ARTICLE HISTORY
Received  May 
Accepted  October 
A one-pot reaction of a sodium 2-cyanoethylene-1-thiolate salt
with 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl bro-
mides affords a new class of cyanoethylene thioglycosides. The
conversion to the corresponding 5-aminopyrazoles confirms the
E-configuration of these cyanoethylene thioglycosides.
KEYWORDS
Cyanoethylene;
thioglycosides;
cyanoethylene
thioglycosides; pyrazoles;
sodium
-cyanoethylene--thiolate
salts
Introduction
In recent years nucleoside analogs have occupied a significant position in the search
for effective chemtherapeutic agents, owing to the fact that a large number of
unnatural nucleoside derivatives have been shown to have different bioactivities.[1]
The heterocyclic thioglycosides constitute a class of analogs with potential bio-
logical activity.[2] As a part of our program directed towards the development of
new, simple and efficient procedures for the synthesis of antimetabolites,[3–7] it has
been recently described that pyridine and dihydropyridine thioglycosides exerted
inhibitory effects on both DNA and RNA containing viruses and inhibitors of pro-
tein glycosylation, respectively.[8–13] During our studies of nucleoside analogues
a route for the synthesis of S-glycosides bearing an open chain–acrylamide and
acrylohydrazide-aglycone, which were found to have pharmaceutically useful anti-
cancer activity.[14–15] These common features encouraged us to continue our efforts
for the development of simple and cost-effective methodologies for the synthesis of
cyanoethylene thioglycosides.
CONTACT Galal Elgemeie
sity,  Helwan, Cairo, Egypt.
elgemeie@yahoo.com
Chemistry Department, Faculty of Science, Helwan Univer-
©  Taylor & Francis Group, LLC

2
G. ELGEMEIE ET AL.
Scheme . Synthetic pathway for a,b, a,b and a,b.
Results and discussion
Here we report the synthesis of cyanoethylene thioglycoside derivatives as a new
class of glycosides. The potassium 2-cyanoethylene-1-thiolate salt 3 was chosen as
the key intermediate. The sequence of reactions, followed in the preparation of the

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
3
designed compounds is summarized in Scheme 1. Thus, it has been found that 2-
benzoylacetonitrile 1 reacted with phenylisothiocyanate in KOH-EtOH with heat-
ing to give the corresponding stable potassium 2-cyano-ethylene-1-thiolate salt 3.
The latter reacts with 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl bro-
mides 5 in ethanol at room temperature to give in a high yield the corresponding
S-glucosides 6a or S-galactosides 6b, respectively. The structures of the reaction
products 6a, b were established by their elemental analyses and spectral data (IR,
MS, 1H NMR and 13C NMR). As an example, the 1H NMR spectrum of 6a showed
the anomeric proton as a doublet atδ 5.2 ppm. The coupling constant (J1´,2´ = 9.3 Hz)
indicated H-1´to be trans-diaxial to H-2´. The other six glucose protons resonated at
3.5–5.2 ppm and the four acetyl groups appeared as four singlets at δ 1.98–2.04 ppm.
The 13C NMR spectrum of 6a contained a signal at δ 88.24 corresponding to the C-
1ꢀ atom and five signals appearing at δ 61.43, 67.5, 69.8, 72.59 and 74.65 that were
assigned to C-6ꢀ, C-4ꢀ, C-2ꢀ, C-3ꢀ, and C-5ꢀ, respectively. Attempted removal of the
protecting groups in 6 by methanolic ammonia has not resulted in formation of the
corresponding free glycosides. It was suggested that structure 6 should be present in
the E form and not in the Z form, which was shown by reacting compounds 6 with
hydrazine derivatives in ethanol-piperidine at room temperature to give the corre-
sponding 5-aminopyrazole derivatives 7. The structures of 7 were established on the
basis of their elemental analysis and spectral data (IR, MS, 1H NMR and 13C NMR).
Structure 7b was supported by its mass (m/z 354), which agrees with its molecu-
lar formula C22H18N4O. Compounds 7 could also be prepared by reaction of the
3-methylthiopyrazoles 8 with aniline. Compounds 8 were prepared by the reaction
of 2-benzoylacetonitrile 1 with carbon disulfide in the presence of sodium hydride-
DMF followed by alkylation with methyl iodide to give the corresponding ketene
S,S-acetal 4. The latter reacts with hydrazine derivatives at room temperature to give
5-aminopyrazoles 8 (Scheme 1). Attempted reaction of compound 4 with hydrazines
in ethanol under refluxing conditions resulted in the formation of the pyrazole-4-
carbonitriles 10, which react with aniline under heat to give the 3-anilinopyrazoles
11. Compounds 11 could also be prepared by alkylation of the potassium 2- cyano-
ethylene-1-thiolate salt 3 with methyl iodide at room temperature followed by
reaction with hyrdazines in refluxing ethanol (Scheme 2). In order to explore the
possibility that this reaction may occur with other classes of cyanoketene thiolate
salts, the reaction of α-glycosyl halides 5 with 14 was investigated as shown in
Scheme 3. Compounds 14 were prepared from the reaction of malononitrile or ethyl
cyanoacetate 12a,b with phenyl- and alkyl isothiocyanates in the presence of EtOH-
KOH. Thus, we treated 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl
bromides 5with one equivalent of 14 at room temperature, and obtained the cor-
responding S-glucosides 16a-c&g-I or S-galactosides 16d-f&k-m, respectively. The
structures of 16 were established on the basis of their elemental analyses, MS and
1H NMR. Reaction of compounds 16 with hydrazine in refluxing ethanol gave the
corresponding pyrazole derivatives 17. The structures of 17 were established on the
basis of their elemental analysis and spectral data. Structure 17a was supported by
its mass (m/z 199), which agrees with its molecular formula C10H9N5.

4
G. ELGEMEIE ET AL.
Scheme . Synthetic pathway for pyrazoles a,b and a,b.
Conclusion
In conclusion, a novel synthesis of interesting new class of acyclic cya-
noethylene thioglycosides was achieved by the reaction of the potassium
2-cyanoethylene-1-thiolate salts with α-glycosyl halides. These acyclic glycosides
can be utilized as excellent starting materials for the synthesis of pyrazoles and other
interesting carbohydrate derivatives.
Experimental
All melting points were measured on a Gallenkamp melting point apparatus. IR
spectra were collected in the transmission mode on a Pye Unicam Spectra-1000
spectrometer. 1H- and 13C NMR spectra were measured on a Jeol-500 MHz spec-
trometer for solutions DMSO-d6 and CDCl3 using Si(CH3)4 as an internal stan-
dard at National Research Center, Cairo, Egypt. Mass spectra were recorded by EI
on a Varian Mat 311A spectrometer and FAB on a kratos MS 50 spectrometer. The
progress of the reactions was monitored by TLC using aluminum sheets coated with
silica gel F254 (Merck). Viewing under a short-wavelength UV lamp effected detec-
tion.

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
5
Scheme . Synthetic pathway for a-f,a-f,a-l and a-f.
General procedure for the synthesis of 4
A solution of ω-cyanoacetophenone (0.2 mol) in dry benzene (200 mL) was added
to a suspension of sodium hydride (0.4 mol) in 150 mL benzene. The mixture
was stirred for 20 min., Carbon disulphide (0.2 mol) was added. The stirring was
continued for 30 min., DMF was then added (150 mL), the reaction was com-
pleted by slight heating, and then cooled to 10 °C. Then the solution left to evap-
orate at room temperature and the formed solid product was added to methyl
iodide (0.4 mol) in benzene and stirred overnight. Water was added and the ben-
zene layer was extracted for several times with water to remove the remaining

6
G. ELGEMEIE ET AL.
DMF. The benzene layer was dried and evaporated. The formed solid was collected
and recrystalized from ethanol to give a pale yellow crystals. (m.p. 70–71°C), 90%
yield.
General procedure for the synthesis of 6a,b
A mixture of ω-cyanoacetophenone (1.45 g, 0.01mol) and phenyl isothiocyanate
(0.01 mol) was heated for 10–20 minutes in ethanol (25 mL) containing potassium
hydroxide (0.01 mol). After cooling, a solution of 2,3,4,6-tetra-O-acetyl-a-D-gluco-
or galactopyranosyl bromide (0.01 mol) in acetone (20 mL) was added. The reaction
mixture was stirred at room temperature until completion (TLC), and then con-
centrated and separated by filtration and washed with distilled water to remove the
formed potassium bromide. The resulting solid product was dried and crystallized
from ethanol to give the title compounds.
(1E)-Anilino-1-(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-glucopyranosylthio)-2-benzoyl-2-
cyanoethylene (6a)
1
Yellow solid; (EtOH), yield (87%), mp 175–7 °C. H NMR (500 MHz, DMSO):
δ 1.98 - 2.04 (4s, 12H, 4 x CH3CO), 3.5–3.55 (m, 2H, 6ꢀ-H2), 3.98 (m, 1H, 5ꢀH)
4.15 (m, 1H, 4ꢀ-H), 4.97- 5.10 (m, 2H, 3ꢀ-H, 2ꢀ-H), 5.2 (d,1H, J1´,2´ = 9.3 Hz, 1ꢀ-H),
7.2–7.55 (m, 10H, 2 C6H5), 14.02 (s,1H, NH). 13C NMR: δ 20.18–20.35 (4 CH3),
61.43 (CH2, C-6ꢀ), 67.5 (C-4ꢀ), 69.8 (C-2ꢀ), 72.59 (C-3ꢀ), 74.65 (C-5ꢀ), 88.24 (C-1ꢀ),
119.23 (CN), 122.87–138.06 (2 C6H5), 138.54 (C-2), 140.60 (C-3), 165.30 (C-1),
169.05–169.82 (5 CO). Anal. Calcd. For. C30H30N2O10S (610.48): C, 59.01; H, 4.94;
N, 4.58%. Found: C, 59.1; H, 4.88; N, 4.61%.
(1E)-Anilino-1-(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-galactopyranosylthio)-2-benzoyl-2-
cyanoethylene (6b)
1
Yellow solid; (EtOH), yield (86%), mp 186–7 °C, H NMR (500 MHz, DMSO):
δ 1.93 - 1.97 (4s, 12H, 4 CH3CO), 3.5–4.19 (m, 2H, 6ꢀ-H2), 4.86 - 4.90 (m, 1H,
5ꢀH), 4.95 (m, 1H, 4ꢀ-H), 5.34 - 5.40 (m, 3H, 3ꢀ-H, 2ꢀ-H, 1ꢀ-H), 7.29–7.78 (m, 10H,
2 C6H5). 13C NMR: δ 20.00–20.49 (4 CH3), 60.22 (CH2, C-6ꢀ), 66.8 (C-4ꢀ), 69.0 (C-
2ꢀ), 71.21 (C-3ꢀ), 73.99 (C-5ꢀ), 87.89 (C-1ꢀ), 118.76 (CN), 121.95–137.66 (2 C6H5),
138.00 (C-2), 141.27 (C-3), 164.80 (C-1), 168.55–169.00 (5 CO). Anal. Calcd. For.
C30H30N2O10S (610.48): C, 59.01; H, 4.94; N, 4.58%. Found: C, 59.04; H, 4.87; N,
4.55%.
General procedures for the synthesis of 7a,b
Method A: mixture of compounds 6a,b (0.01 mol) and hydrazine hydrate 90%
(0.01 mol) in ethanol (30 mL) and few drops of piperidine was stirred at room

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
7
temperature for 8 hours. The resulting solid product was collected by filtration and
recrystallized from ethanol to give title compound in 50–55% yield.
Method B: mixture of compounds 8a,b (0.01 mol) and aniline (0.01 mol) in ethanol
(30 mL) was refluxed for two hours. The resulting solid product was collected by
filtration and recrystallized from ethanol to give title compound in 65–75% yield.
[5-Amino-3-anilino-1H-pyrazol-4-yl](phenyl)methanone (7a)
Brown solid; (EtOH), yield, 70%, mp 224–6 °C, IR: νmax/cm−1 (KBr) 3400, 3320
(NH, NH2), 1670 (CO). 1H NMR (500 MHz, DMSO): 6.00 (s, 2H, NH2); 6.70–7.69
(m, 10H, 2 C6H5), 8.88 (s, 1H, NH), 11.32 (s, 1H, NH). Anal. Calcd. For. C16H14N4O
(278.3): C, 69.02; H, 5.07; N, 20.13%. Found: C, 69.12; H, 5.02; N, 20.33%.
[5-Amino-3-anilino-1-phenyl-1H-pyrazol-4-yl](phenyl)methanone
(7b).
Brown solid; (EtOH), yield, 79%, mp 212–4°C. IR νmax/cm−1 (KBr): 3430, 3300
1
(NH, NH2); 1677 (CO). H NMR (500 MHz, DMSO): 6.22 (s, 2H, NH2), 6.80 -
7.99 (m, 15H, 3C6H5), 11.00 (s, 1H, NH). Anal. Calcd. For. C22H18N4O (354.39): C,
74.50; H, 5.11; N, 15.8%. Found: C, 74.31; H, 5.09; N, 15.92%. MS:El, 70 eV [M]+;
m/z = 354 (1.5%).
General procedure for the synthesis of 8a,b
A mixture of compounds 4 (0.01 mol) and N–substituted hydrazines (0.01 mol) in
ethanol (30 mL) and few drops of pipredine was stirred for eight hours at room tem-
perature. The resulting solid product was collected by filtration and recrystallized
from ethanol to give title compound.
[5-Amino-3-(methylthio)-1H-pyrazol-4-yl](phenyl)methanone (8a.) Yellow
solid; (EtOH), yield, 65%, mp 120–2 °C. 1H NMR (500 MHz, DMSO): 2.23 (s, 3H,
SCH3), 5.80 (s, 2H NH2), 6.80–7.59 (m, 5H, C6H5), 8.99 (s, 1H, NH). Anal. Calcd.
For. C11H11N3OS (233.28): C, 56.6; H, 4.70; N, 18.01%. Found: C, 56.44; H, 4.86;
N, 18.22%.
[5-Amino-3-(methylthio)-1-phenyl-1H-pyrazol-4-yl](phenyl)methanone (8b)
Yellow solid; (EtOH), yield, 85%, mp 127–9 °C. 1H NMR (500 MHz, DMSO): 2.28
(s, 3H, SCH3), 6.00 (s, 2H NH2), 6.70–7.88 (m, 10H, 2C6H5). Anal. Calcd. For.
C17H15N3OS (309.37): C, 65.90; H, 4.80; N, 13.30%. Found: C, 65.64; H, 4.78; N,
13.80%. MS:El,70 eV [M-3]+; m/z = 306 (2.5%).
General procedure for the synthesis of 9
A mixture of ω-cyanoacetophenone (1.45 g, 0.01 mol) and phenyl isothiocyanate
(0.01 mol) was heated for 10–20 minutes in ethanol (25 mL) containing potassium
hydroxide (0.01 mol). After cooling, methyl iodide (1.4 mL, 0.01 mol) is added

8
G. ELGEMEIE ET AL.
and stirred at room temperature for 2 hours. The solution was evaporated and the
formed solid product was collected by filtration to give the title compound.
(1E)-Anilino-1-(methylthio)-2-benzoyl-2-cyanoethylene (9)
Yellow crystals; yield (65–75%), mp 78 0C, IR νmax/cm−1 (KBr): 3330, 3230 (NH),
2220 (CN), 1660 (CO).1H NMR (500 MHz, DMSO): δ 2.44 (s, 3H, SCH3), 7.22–
7.75 (m, 10H, 2 C6H5), 12.82 (s,1H, NH). 13C NMR δ 22.38 (SCH3), 115.00 (CN),
122.34–132.00 (2 C6H5), 137.44 (C-2), 141.20 (C-3), 161.90 (C-1), 168.00 (CO).
Anal. Calcd. For. C17H14N2OS (294.37) C, 69.36; H, 4.79; N, 9.52; O, 5.44; S, 10.89%.
Found: C, 69.25; H, 4.75; N, 9.59; O, 5.50; S, 10.79%. MS: El,70 eV [M]+; m/z = 294
(12.9%).
General procedure for the synthesis of 10a,b
A mixture of compounds 4 (0.01 mol) and N–substituted hydrazines (0.01 mol) in
ethanol (30 mL) was refluxed for 2 hours. The resulting solid product was collected
by filtration and recrystallized from ethanol to give the title compound.
3-(Methylthio)(5-phenyl)-1H-pyrazole-4-carbonitrile (10a)
Yellow solid; (EtOH), yield, 69%, mp 147–9 °C.IR: νmax/cm−1 (KBr): 3448 (NH),
1
2224 (CN). H NMR (500 MHz, DMSO): 2.20 (s, 3H, SCH3), 6.66–7.80 (m, 5H,
C6H5), 9.90 (s, 1H, NH). Anal. Calcd. For. C11H9N3S (215.28) C, 61.37; H, 4.21; N,
19.52; S, 14.89%. Found: C, C, 61.42; H, 4.18; N, 19.44; S, 14.80%, MS: El, 70 eV
[M]+; m/z = 215 (100%).
3-(Methylthio)(1,5-diphenyl)-1H-pyrazole-4-carbonitrile (10b)
Orange solid; (EtOH), yield, 70%, mp 133 °C. IR: νmax/cm−1 (KBr): 2220 (CN). 1H
NMR (500 MHz, DMSO): 2.40 (s, 3H, SCH3), 6.70–7.99 (m, 10H, C6H5).). Anal.
Calcd. For. C17H13N3S (291.39) C, 70.08; H, 4.50; N, 14.42; S, 11.00%. Found:C,
70.08; H, 4.41; N, 14.31; S, 10.89%, MS: El, 70 eV [M]+; m/z = 291 (71.4%).
General procedures for the synthesis of 11
Method A: mixture of compounds 9 (0.01 mol) and hydrazine hydrate 90%
(0.01 mol) in ethanol (30 mL) and was refluxed for 2 hours. The resulting solid
product was collected by filtration and recrystallized from ethanol to give the title
compound.
Method B: mixture of compounds 10a (0.01 mol) and aniline (0.01 mol) in ethanol
(30 mL) was refluxed for two hours. The resulting solid product was collected by
filtration and recrystallized from ethanol to give the title compound.

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
9
5-Phenyl-3-(phenylamino)-1H-pyrazole-4-carbonitrile (11a)
Yellow solid; (EtOH), yield, 75%, mp 224–6 °C. IR: νmax/cm−1 (KBr): 3330, 3200
1
(NH); 2225 (CN). H NMR (500 MHz, DMSO): 6.50–7.74 (m, 10H, 2 C6H5),
10.55 (s, 1H, NH). Anal. Calcd. For. C16H12N4(260.28)C, 73.83; H, 4.65; N, 21.52%.
Found: C, 73.88; H, 4.67; N, 21.59%, MS: El, 70 eV [M]+; m/z = 260 (100%).
1,5-diphenyl-3-(phenylamino)-1H-pyrazole-4-carbonitrile (11b)
Yellow solid; (EtOH), yield, 70%, mp 260–62 °C. IR: νmax/cm−1 (KBr): 3420, 3300
1
(NH); 2220 (CN). H NMR (500 MHz, DMSO): 6.20–7.90 (m, 15H, 3 C6H5),
11.01 (s, 1H, NH). Anal. Calcd. For. C22H16N4(336.00)C, 78.57; H, 4.76; N, 16.67%.
Found: C, 78.68; H, 4.66; N, 16.59%, MS: El, 70 eV [M]+; m/z = 336 (70%).
General procedure for the synthesis of 15a-f
A mixture of 12 (0.6 g, 1 mol) and N-substituted isothiocyanate (0.01 mol)
was heated for 30 minutes in ethanol (25 mL) containing potassium hydroxide
(0.01 mol) and then evaporated. The separated residue was stirred overnight with
methyl iodide (1.40 mL, 0.01mol) in ethanol (25 mL). The solution was evaporated
and the formed solid was collected by filtration and then recrystallized from ethanol
to give the title compound.
2-[(Phenylamino)(methylthio)methylene]malononitrile (15a)
White solid; (EtOH), yield (75%), mp 93–6 °C. IR νmax/cm−1 (KBr): 3350, 3250
(NH), 2225 (CN).1H NMR (500 MHz, DMSO): δ 2.60 (s, 3H, SCH3), 7.18–7.85 (m,
5H, C6H5), 10.34 (s,1H, NH). Anal. Calcd. For. C11H9N3S (215.27): C, 61.37; H,
4.21; N, 19.52; S, 14.89%. Found: C, 61.26; H, 4.41; N, 19.55; S, 14.88%.
2-[(Ethylamino)(methylthio)methylene]malononitrile (15b)
Yellow solid; (EtOH), yield (73%), mp 73–4 °C. IR νmax/cm−1 (KBr): 3430, 3330
(NH), 2220 (CN).1H NMR (500 MHz, DMSO): δ 1.23 (t, 3H, CH3), 2.56 (s, 3H,
SCH3), 4.02 (q, 2H, CH2), 10.34 (s,1H, NH). Anal. Calcd. For. C7H9N3S (167.23):
C, 50.27; H, 5.42; N, 25.13; S, 19.17%. Found: C, 50.27; H, 5.33; N, 25.25; S, 19.10%.
2-[(Methylamino)(methylthio)methylene]malononitrile (15c)
Yellow solid; (EtOH), yield (77%), mp 77–9 °C. IR νmax/cm−1 (KBr): 3400, 3300
(NH), 2220 (CN).1H NMR (500 MHz, DMSO): δ 2.32 (s, 3H, CH3), 2.76 (s, 3H,
SCH3), 10.00 (s,1H, NH). Anal. Calcd. For. C6H7N3S (153.2): C, 47.04; H, 4.61; N,
27.43; S, 20.93%. Found: C, 47.12; H, 4.65; N, 27.63; S, 20.99%.

10
G. ELGEMEIE ET AL.
2-Ethyl-2-cyano-3-phenylamino)-3-(methylthio) acrylate (15d)
White solid; (EtOH), yield (65%), mp 95–7 °C. IR νmax/cm−1 (KBr): 3450, 3200
(NH), 2220 (CN), 1720 (CO).1H NMR (500 MHz, DMSO): δ 1.15 (t, 3H, CH3),
2.60 (s, 3H, SCH3), 4.05 (q, 2H, CH2), 7.22–7.95 (m, 5H, C6H5), 11.24 (s,1H, NH).
Anal. Calcd. For. C13H14N2O2S (262.33): C, 59.52; H, 5.38; N, 10.68; O, 12.20; S,
12.22%. Found: C, 59.62; H, 5.44; N, 10.77; O, 12.17; S, 12.28%.
2-Ethyl-2-cyano-3-ethylamino)-3-(methylthio) acrylate (15e)
White solid; (EtOH), yield (71%), mp 83–6 °C. IR νmax/cm−1 (KBr): 3450, 3200
(NH), 2220 (CN), 1720 (CO).1H NMR (500 MHz, DMSO): δ 1.10 (t, 3H, CH3),1.19
(t, 3H, CH3), 2.70 (s, 3H, SCH3), 3.87 (q, 2H, CH2), 4.10 (q, 2H, CH2), 11.00 (s,1H,
NH). Anal. Calcd. For. C9H14N2O2S (214.28): C, 50.45; H, 6.59; N, 13.07; O, 14.93;
S, 14.96%. Found: C, 50.55; H, 6.59; N, 13.11; O, 14.77; S, 14.87%.
2-Ethyl-2-cyano-3-methylamino)-3-(methylthio) acrylate (15f)
Yellow solid; (EtOH), yield (67%), mp 71–4 °C. IR νmax/cm−1 (KBr): 3400, 3320
(NH), 2228 (CN), 1730 (CO).1H NMR (500 MHz, DMSO): δ 1.12 (t, 3H, CH3),
2.40 (s, 3H, CH3), 2.60 (s, 3H, SCH3), 3.99 (q, 2H, CH2),11.50 (s,1H, NH). Anal.
Calcd. For. C8H12N2O2S (200.26): C, 47.98; H, 6.04; N, 13.99; O, 15.98; S, 16.01%.
Found: C, 47.78; H, 6.14; N, 13.77; O, 15.91; S, 16.07%.
General procedure for the synthesis of 16a-m
A mixture of 12 (0.6 g, 1 mol) and N-substituted isothiocyanate (0.01 mol) was
heated for 10–20 minutes in ethanol (25 mL) containing potassium hydroxide
(0.01 mol). After cooling, a solution of 2,3,4,6-tetra-O-acetyl-a-D-gluco- or galac-
topyranosyl bromide (0.01 mol.) in acetone (20 mL) was added. The reaction mix-
ture was stirred at room temperature until completion (TLC), and then evaporated;
the residue was washed with distilled water to remove the formed potassium bro-
mide and then recrystallized from ethanol.
2-[(Phenylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-glucopyranosylthio)-
methylene]malononitrile (16a)
White solid; (EtOH), yield (87%), mp 193–5 °C. 1H NMR (500 MHz, DMSO): δ 1.90
- 2.03 (4s, 12H, 4CH3CO), 3.4 (s, 2H, 6ꢀ-H2), 4.05–4.4 (m, 2H, 4ꢀ-H, 5ꢀ-H), 5.00 (t,
1H, J = 9.1Hz, 3ꢀ-H), 5.35 - 5.40 (m, 1H, 2ꢀ-H), 5.45–5.51 (d, 1H, J = 9.4Hz, 1ꢀ-H),
7.2–7.55 (m, 5H, C6H5), 10.76 (s,1H, NH). Anal. Calcd. For. C24H25N3O9S (532.09):
C, 54.17; H, 4.73; N, 7.89%. Found: C, 54.24; H, 4.92; N, 7.37%.

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
11
2-[(Ethylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-glucopyranosylthio)-
methylene]malononitrile (16b)
1
Yellow solid; (EtOH), yield (86%), mp 125–8 °C. H NMR (500 MHz, DMSO):
δ 1.35–1.4 (t, 3H, CH3), 2.07–2.11 (m, 12H, 4CH3CO), 3.70–3.73 (m, 2H, 6ꢀ-
H2), 3,90 (q, 2H, CH2), 4.13–4.29 (m, 2H, 5ꢀ-H, 4ꢀ-H), 4.9–5.00 (m, 1H, 3ꢀ-H),
5.04–5.24 (m, 2H, 2ꢀ-H, 1ꢀ-H), 6.82 (s, 1H, NH). Anal. Calcd. For. C20H25N3O9S
(483.3): C, 49.70; H, 5.20; N, 8.69%. Found: C, 49.88; H, 5.35; N, 8.56%.
2-[(Methylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-glucopyranosylthio)-
methylene]malononitrile (16c)
1
Yellow solid; (EtOH), yield (77%), mp 177–9 °C. H NMR (500 MHz, DMSO): δ
1.58 (s, 3H, CH3), 2.03–2.14 (4s, 12H, 4CH3CO), 3.35–3.42 (d, 2H, J = 9.8 Hz, CH2),
3.82–4.11 (m, 2H, 6ꢀ-H2), 4.22–4.26 (m, 2H, 5ꢀ-H, 4ꢀ-H), 4.81–4.84 (m, 1H, 3ꢀ-H),
5.10–5.20 (m, 1H, 2ꢀ-H), 5.24–5.35 (d, 1H, J = 9.6Hz,1ꢀ-H), 6.78 (s,1H, NH). Anal.
Calcd. For. C19H23N3O9S (469.30): C, 48.62; H, 4.93; N, 8.95%. Found: C, 48.56; H,
4.78; N, 8.77%.
2-[(Phenylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-galactopyranosylthio)-
methylene]malononitrile (16d)
White solid; (EtOH), yield (88%), mp 200 °C, 1H NMR (500 MHz, DMSO): δ 1.70–
2.13 (4s, 12H, 4CH3CO), 3.36 (m, 2H, 6ꢀ-H2), 4.03 (m, 1H, 5ꢀ-H), 4.20 (m, 1H, 4ꢀ-
H), 5.15–5.31 (m, 2H, 3ꢀ-H, 2ꢀ-H), 5.48 (d,1H, J = 9.1 Hz, 1ꢀ-H), 7.21–7.40 (m, 5H,
C6H5), 10.25 (s, 1H, NH). Anal. Calcd. For. C24H25N3O9S (532.09): C, 54.17; H,
4.73; N, 7.89%. Found: C, 54.21; H, 4.81; N, 7.77%.
2-[(Ethylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-galactopyranosylthio)-
methylene]malononitrile (16e)
1
Yellow solid; (EtOH), yield (85%), mp 115–8 °C. H NMR (500 MHz, DMSO): δ
1.11 (t, 3H, CH3), 1.98–2.10 (4s, 12H, 4CH3CO), 3.95–3.98 (m, 3H, 6ꢀ-H2, 5ꢀ-H),
4.09 (q, 2H, CH2), 4.25 (m, 1H, 4ꢀ-H), 4.95–5.30 (m, 2H, 3ꢀ-H, 2ꢀ-H), 6.17 (d, 1H,
J = 9.8 Hz, 1ꢀ-H), 9.93 (s, 1H, NH). Anal. Calcd. For. C20H25N3O9S (483.3): C, 49.70;
H, 5.20; N, 8.69%. Found: C, 49.87; H, 5.25; N, 8.76%.
2-[(Methylamino)(2ꢀ,3ꢀ,4ꢀ,6ꢀ-tetra-O-acetyl-β-D-galactopyranosylthio)-
methylene]malononitrile (16f)
Yellow solid; (EtOH), yield (86%), mp 210 °C. 1H NMR (500 MHz, DMSO): δ 1.34
(s, 3H, CH3), 2.00–2.18 (4s, 12H, 4CH3CO), 3.25 (d, 2H, J = 9.4 Hz, 6ꢀ-H2), 4.12
(m, 2H, 4ꢀ-H, 5ꢀ-H), 5.08 (m, 1H, 3ꢀ-H), 5.30 (t, 1H, J = 9.2 Hz, 2ꢀ-H), 5.47 (d, 1H,
J = 10.2 Hz, 1ꢀ-H). Anal. Calcd. For. C19H23N3O9S (469.30): C, 48.62; H, 4.93; N,
8.95%. Found: C, 48.68; H, 4.55; N, 8.83%.

12
G. ELGEMEIE ET AL.
(2Z)-Ethyl-2-cyano-3-phenylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-glucopyr-
anosylthio)acrylate (16g)
White solid; (EtOH), yield (87%), mp 193–5 °C. 1H NMR (500 MHz, DMSO): δ 1.25
(q, 3H, CH3), 1.89–2.1 (4s, 12H, 4CH3CO), 3.47 (q, 2H, CH2), 4.00 (m, 3H, 5ꢀ-H,
6ꢀ-H2), 4.86 (m, 2H, 3ꢀ-H,4ꢀ-H), 5.2 (t, 1H, J = 9.5 Hz, 2ꢀ-H), 5.3–5.35 (d, 1H, J =
10.3 Hz, 1ꢀ-H), 7.2–7.4 (m, 5H, C6H5). Anal. Calcd. For. C26H30N2O11S (578.52): C,
53.97; H, 5.22; N, 4.84%. Found: C, 53.84; H, 5.41; N, 4.76%.
(2Z)-Ethyl-2-cyano-3-ethylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-glucopy-
ranosylthio)acrylate (16h)
1
White solid; (EtOH), yield (87%), mp 193–5 °C. H NMR (500 MHz, DMSO): δ
1.20 (t, 3H, CH3), 1.34 (t, 3H, CH3), 1.99–2.12 (4s, 12H, 4CH3CO), 3.67 (m, 2H,
6ꢀ-H), 3.72 (q, 2H, CH2), 3.88 (q, 2H, CH2), 4.09- 4.25 (m, 2H, 5ꢀ-H, 4ꢀ-H), 5.03–
5.09 (m, 2H, 2ꢀ-H, 3ꢀ-H), 5.19 (m, 1H, 1ꢀ-H), 10.2 (s,1H, NH). Anal. Calcd. For.
C22H30N2O11S (530.4): C, 49.81; H, 5.69; N, 5.28%. Found: C, 49.87; H, 5.45; N,
5.19%.
(2Z)-Ethyl-2-cyano-3-methylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-glucopy-
ranosylthio)acrylate (16i)
1
Yellow solid; (EtOH), yield (77%), mp 165–7 °C. H NMR (500 MHz, DMSO): δ
1.31 (t, 3H, CH3), 2.01–2.06 (4s, 12H, 4CH3CO), 2.14 (s, 3H, CH3), 3.19 (s, 2H,
6ꢀ-H2), 3.89 (m, 1H, 5ꢀ-H), 4.16–4.25 (m, 2H, 4ꢀ-H, 3ꢀ-H), 5.12–5.27 (m, 1H, 1ꢀ-H),
10.01(s, 1H, NH). Anal. Calcd. For. C21H28N2O11S (516.4): C, 48.84; H, 5.45; N,
5.42%. Found: C, 48.76; H, 5.41; N, 5.40%.
(2Z)-Ethyl-2-cyano-3-phenylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-galactopy-
ranosylthio)acrylate (16j)
Yellow solid; (EtOH), yield (88%), mp 80–3 °C. 1H NMR (500 MHz, DMSO): δ 1.26
(t, 3H, CH3), 1.86–1.97 (4s, 12H, 4CH3CO), 3.63 (m, 2H, 6ꢀ-H2), 3.86 (m, 1H, 5ꢀ-
H), 4.06 (q, 2H, CH2), 4.17–4.24 (m, 2H, 3ꢀ-H,4ꢀH), 5.04–5.1 (t, 1H, J = 9.1 Hz,
2ꢀ-H), 5.26 (d, 1H, J = 10.1Hz, 1ꢀH), 7.1–7.35 (m, 5H, C6H5), 11.46 (s,1H, NH).
Anal. Calcd. For. C26H30N2O11S (578.52): C, 53.97; H, 5.22; N, 4.84%. Found: C,
53.80; H, 5.19; N, 4.93%.
(2Z)-Ethyl-2-cyano-3-ethylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-galactopy-
ranosylthio)acrylate (16k)
Yellow solid; (EtOH), yield (85%), mp 139 °C. 1H NMR (500 MHz, DMSO): δ 1.20
(t, 3H, CH3), 1.28 (t, 3H, CH3), 1.9–2.06 (4s, 12H, 4CH3CO), 3.66 (q, 2H, CH2),
3.77 (q, 2H, CH2), 4.1- 4.08 (m, 2H, 6ꢀ-H2), 4.22–4.27 (m, 2H,4ꢀ-H, 5ꢀ-H), 5.1 (t,

NUCLEOSIDES, NUCLEOTIDES AND NUCLEIC ACIDS
13
1H, J = 9.8 Hz, 3ꢀ-H), 5.25 (t, 1H, J = 9.7 Hz, 2ꢀ-H), 5.46 (d, 1H, J = 10.6 Hz, 1ꢀ-
H), 10.2(s,1H, NH). Anal. Calcd. For. C22H30N2O11S (530.4): C, 49.81; H, 5.69; N,
5.28%. Found: C, 49.75; H, 5.73; N, 5.32%.
(2Z)-Ethyl-2-cyano-3-methylamino)-3-(2ꢀ,3ꢀ,4ꢀ,6ꢀ,tetra-O-acetyl-β-D-galactopy-
ranosylthio) acrylate (16l)
1
Yellow solid; (EtOH), yield (86%), mp 115–8 °C. H NMR (500 MHz, DMSO): δ
1.17–1.51 (t, 3H, CH3), 1.83 (s, 3H, CH3), 1.91–2.11 (4s, 12H, 4CH3CO), 3.18 (q,
2H, CH2), 3.85–4.14 (m, 2H, 6ꢀ-H2), 4.16–4.19 (m, 1H, 5ꢀ-H), 4.94–5.03 (m, 2H,
4ꢀ-H, 3ꢀ-H), 5.02–5.38 (m, 2H, 2ꢀ-H, 1ꢀ-H), 10.01 (s, 1H, NH). Anal. Calcd. For.
C21H28N2O11S (516.4): C, 48.84; H, 5.45; N, 5.42%. Found: C, 48.91; H, 5.34; N,
5.36%
General procedures for the synthesis of 17a–f
Method A: A mixture of compounds (15a–f) (0.01 mol) and hydrazine hydrate 90%
(0.5 mL, 0.01 mol) in ethanol (30 mL) was refluxed for two hours. The resulting
solid product was collected by filtration and recrystallized from ethanol to give the
title compound in 74%–78% yield.
Method B: A mixture of compounds (16a–m) (0.01 mol) and hydrazine hydrate 90%
(0.5 mL, 0.01 mol) in ethanol (30 mL) was refluxed for two hours. The resulting solid
product was collected by filtration and recrystallized from ethanol. These products
were found to be identical with those obtained in method (A) with a yield 50%–
55%.
5-Amino-3-(phenylamino)-1H-pyrazole-4-carbonitrile(17a)
Yellow solid; (EtOH), yield, 75%, mp 210–12 °C. IR: νmax/cm−1 (KBr) 3450, 3370
(NH, NH2); 2220 (CN). 1H NMR (500 MHz, DMSO): 6.20 (s, 2H, NH2), 6.75–7.60
(m, 5 H, C6H5), 8.50 (s, 1H, NH), 10.00 (s, 1H, NH). Anal. Calcd. For C10H9N5
(199)C, 60.29; H, 4.55; N, 35.16%. Found: C, 60.33; H, 4.61; N, 35.22%, MS: El, 70 eV
[M]+; m/z = 199 (100%).
5-Amino-3-(ethylamino)-1H-pyrazole-4-carbonitrile(17b)
Yellow solid; (EtOH), mp 106–7 °C. Anal. Calcd. For. C6H9N5 (151.16) C, 47.67; H,
6.00; N, 46.33%. Found: C, 47.59; H, 6.12; N, 46.40%, MS: El, 70 eV [M]+; m/z =
151 (62.8%).
5-Amino-3-(methylamino)-1H-pyrazole-4-carbonitrile(17c)
Yellow solid; (EtOH), yield 75%, mp 146–8 °C. IR: νmax/cm−1 (KBr) 3450, 3300
(NH, NH2); 2225 (CN). 1H NMR (500 MHz, DMSO): 2.43 (s, 3H, CH3), 6.33 (s,

14
G. ELGEMEIE ET AL.
2H, NH2), 8.00 (s, 1H, NH), 10.50 (s, 1H, NH). Anal. Calcd. For. C5H7N5 (137.24)
C, 43.79; H, 5.14; N, 51.07%. Found: C, 43.81; H, 5.10; N, 51.11%, MS: El, 70 eV
[M]+; m/z = 137 (100%).
Ethyl-5-amino-3-(phenylamino)-1H-pyrazole-4-carboxylate (17d)
Brown solid; (EtOH), yield, 75%, mp 208–9 °C. IR: νmax/cm−1 (KBr) 3350, 3200
(NH, NH2); 1720 (CO). 1H NMR (500 MHz, DMSO): 1.50 (t, 3H, CH3), 4.00 (q,
2H, CH2), 6.00 (s, 2H, NH2), 6.40–7.80 (m, 5 H, C6H5), 8.90 (s, 1H, NH), 10.50
(s, 1H, NH). Anal. Calcd. For. C12H14N4O2 (246.11) C, 58.53; H, 5.73; N, 22.75; O,
12.99%. Found: C, 58.49; H, 5.70; N, 22.66; O, 12.81%, MS: El, 70 eV [M]+; m/z =
246 (75%).
Ethyl-5-amino-3-(ethylamino)-1H-pyrazole-4-carboxylate (17e)
Brown solid; (EtOH), yield, 75%, mp 105–8 °C. Anal. Calcd. For. C8H14N4O2(198.2)
C, 48.47; H, 7.12; N, 28.26; O, 16.14%. Found: C, 48.44; H, 7.09; N, 28.30; O, 16.10%,
MS: El, 70 eV [M-1]+; m/z = 197 (36.4%).
Ethyl-5-amino-3-(methylamino)-1H-pyrazole-4-carboxylate (17f)
Orange solid; (EtOH), yield, 75%, mp 92–4 °C. IR: νmax/cm−1 (KBr) 3300, 3200
1
(NH, NH2); 1710 (CO). H NMR (500 MHz, DMSO): 1.33 (t, 3H, CH3), 2.44 (s,
3H, CH3), 3.90 (q, 2H, CH2), 6.15 (s, 2H, NH2), 8.70 (s, 1H, NH); 9.46 (s, 1H, NH).
Anal. Calcd. For. C7H12N4O2(184.23) C, 45.64; H, 6.57; N, 30.42; O, 17.37%. Found:
C, 45.61; H, 6.55; N, 30.39; O, 17.41%, MS: El,70 eV [M]+; m/z = 184 (53%).
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