Glycosylation of 4-aryl-1-thioxo[1,2,4]-triazolo[4,3-a]quinazolin-5(4H)-one

Article abstract of DOI:10.1081/CAR-120020479

Reaction of 4-aryl-1-thioxo [1,2,4] triazolo [4,3-a] quinazolin-5 (4H)-ones (2a,b) with acetylated glycosyl bromides 3a-c under alkaline conditions afforded the corresponding S-glycoside derivatives 4, 5 and N-glycoside derivatives 6, 7. Oxidation of S-gl

Full text of DOI:10.1081/CAR-120020479

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Glycosylation of 4‐Aryl‐1‐thioxo[1,2,4] triazolo[4,3‐a]
quinazolin‐5(4H)‐one
Mohamed A. Saleh a & Mohamed F. Abdel‐Megeed a
a Department of Chemistry , Faculty of Science , Tanta University , Tanta, Egypt
Published online: 16 Aug 2006.
To cite this article: Mohamed A. Saleh & Mohamed F. Abdel‐Megeed (2003) Glycosylation of 4‐Aryl‐1‐thioxo[1,2,4]
triazolo[4,3‐a] quinazolin‐5(4H)‐one, Journal of Carbohydrate Chemistry, 22:2, 79-94, DOI: 10.1081/CAR-120020479
To link to this article: http://dx.doi.org/10.1081/CAR-120020479
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JOURNAL OF CARBOHYDRATE CHEMISTRY
Vol. 22, No. 2, pp. 79–94, 2003
Glycosylation of 4-Aryl-1-thioxo[1,2,4]-
triazolo[4,3-a]quinazolin-5(4H)-one
*
Mohamed A. Saleh and Mohamed F. Abdel-Megeed
Department of Chemistry, Faculty of Science, Tanta University, Tanta, Egypt
ABSTRACT
Reaction of 4-aryl-1-thioxo [1,2,4] triazolo [4,3-a] quinazolin-5 (4H)-ones (2a,b) with
acetylated glycosyl bromides 3a–c under alkaline conditions afforded the
corresponding S-glycoside derivatives 4, 5 and N-glycoside derivatives 6, 7.
Oxidation of S-glycosyl derivatives 4, 5 with m-chloroperbenzoic acid yielded the
corresponding sulphones 8, 9, whereas the N-glycosyl derivatives 6, 7 yielded 1-oxo
derivatives 10, 11. However their O-deacetylation with sodium methoxide in
methanol caused cleavage of the S-glycosyl residue and gave N2-glycosylated
analogues 12, 13, 14 and 15.
Key Words: 4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one; O-ace-
tylated glycosyl bromides; S- and N-glycosides; Synthesis and spectral studies.
INTRODUCTION
The 4(3H)-quinazolinone ring system represents an important class of heterocyclic
compounds in medicinal chemistry having anticonvulsant,[1,2] antihypertensive,[3,4]
antidiabetic,[5] and anti-tumor activity.[6–8] On the other hand, heterocycles contain-
ing the 1,2,4-triazole nucleus are considered to be very interesting heterocyclic ring
*
Correspondence: Mohamed A. Saleh, Department of Chemistry, Faculty of Science, Tanta
University, Tanta, Egypt; E-mail: mahsaleh@hotmail.com.
79
DOI: 10.1081/CAR-120020479
0732-8303 (Print); 1532-2327 (Online)
www.dekker.com
Copyright D 2003 by Marcel Dekker, Inc.

80
Saleh and Abdel-Megeed
systems because of their therapeutic importance. For example, derivatives of 1,2,4-
triazole have been found recently to have significant antiseptic[9] and analgesic pro-
perties.[10] Prompted by the aforesaid biological and pharmaceutical activities, and in
continuation of our previous work aimed at introducing carbohydrate moieties into bio-
logically versatile heterocyclic rings to improve their pharmacological activity,[11–16] we
report here the synthesis of a new series of compounds in which a 4-aryl-1-thioxo
[1,2,4] triazolo [4,3-a] quinazolin-5(4H)-one ring is used as a carrier for the glyco-
sidic moiety.
RESULTS AND DISCUSSION
4-Aryl-1-thioxo [1,2,4] triazolo [4,3-a] quinazolin-5 (4H)-ones (2a,b) were pre-
pared by the reaction of 3-aryl-2-thioxo-4 (3H)-quinazolinones[17] with the hydrazine
hydrate in ethanol as the reaction medium.[18,19] The resulting 3-aryl-2-hydrazino-
4(3H)-quinazolinones (1a,b) were cyclized with CS2 in the presence of KOH in
C2H5OH to obtain the desired triazoloquinazolinone derivatives 2a,b and hydrazino deri-
vatives 1a,b also underwent ring closure with CS2 in the presence of pyridine as a base.
Condensation of 2a,b with 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl bromide (3a),
2,3,4,6-tetra-O-acetyl-a-D-galactopyranosyl bromide (3b) or 2,3,4-tri-O-acetyl-a-D-
xylopyranosyl bromide (3c) in acetone and in the presence of K2CO3 each afforded
two products that were separated by silica gel chromatography (3:1, petroleum
ether:Acetone) (Scheme 1).
Scheme 1. Reaction of compounds 2a,b with O-acetylated glycosyl bromides.

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
81
Several instrumental techniques were used to elucidate the structures of the
S-glycosides 4, 5 and N-glycosides 6, 7 (Experimental). The IR spectra generally
indicate the absence of the uNH of compounds 2a,b but show the characteristic fre-
quency of the newly formed functional group(s) (Experimental). The b-configurations
of 4, 5, 6 and 7 were supported by their NMR data (Experimental). The chemical shifts
and coupling constants of anomeric protons (H-1’) in 4, 5, 6 and 7 were in accordance
with the reported value for b-glucosides, b-galactosides and b-xylosides.[20] Large
coupling constants of the anomeric proton in S- and N-glycoside derivatives corres-
ponds to the diaxial orientation of H-1’ and H-2’ protons, indicating the b-configuration
4
and the C1 conformation for this anomer (Experimental).
The 1H NMR spectra provided several pieces of evidence for assigning the
structures of the S- and N-glycosides derivatives. The 1H NMR spectra gave an
interesting peak corresponding to H-9 at d 9.94–9.98 ppm in the case of the
N-glycoside derivatives 6 and 7. This downfield chemical shift is attributed to the
strong interaction between the thione group (C = S) and H-9. This peak was used as an
indicator for the N-glycoside derivatives, whereas the chemical shift for H-9 in the
S-glycoside derivatives 4 and 5 occurs at d 8.22–8.26 ppm. The anomeric proton (H-1’)
1
of N-glycoside derivatives 6 and 7 in the H NMR spectra was observed downfield to
the peak assigned to the anomeric proton of S-glycoside derivatives 4 and 5
(Experimental). This suggested that magnetic anisotropy effects associated with the
thione group (C = S) might be responsible for the deshielding observed for the
anomeric proton.[21,22] The 13C NMR spectra showed a signal at d 164.8–165.2 ppm
due to the thione group (C = S) that is associated with N-glycoside derivatives 6 and
7, while the S-glycoside derivatives 4 and 5 gave the chemical shift at d 144.2–144.6
ppm for the same carbon C-1 (C-S). In the 13C NMR spectra of 6 and 7 the position of
the C-1’ carbon atom is shifted downfield by 4.7 ppm in comparison with the C-1’
(anomeric carbon atom) signal of 4 and 5 (Experimental).
The mass spectra of 4, 5, 6 and 7 do not give reliable evidence to discriminate
between the S- and N-glycoside derivatives. The FAB mass spectra of 4b and 6b
showed the characteristic dissociation of poly-O-acetylated N- and S-glycosides[13,23]
glycosidic bond fragments with m/z 294 [B + 1] (the aglycone) and 331 (the carbohy-
drate moiety). Possible fragmentation patterns of 4b and 6b are presented in Scheme 2.
The regiochemistry of this glycosylation was established by oxidation. Oxidation
of the thioglycosides 4a,b and 5a,c with m-chloroperbenzoic acid in dichloromethane at
room temperature[24] yielded the sulphone derivatives 8a,b and 9a,b respectively
(Scheme 3). Oxidation of the N-glycosides 6a,b and 7a,c under the same conditions
gave the corresponding N-glycoside of 1-oxo derivatives 10a,b and 11a,b, respectively
(Scheme 3).
1
The analytical and spectral data (IR, H NMR, 13C NMR and mass spectra) were
consistent with the assigned structures (Experimental). The analytical data for 9a
revealed a molecular formula C30H30N4O12S. The mass spectrum of 11b was
compatible with the molecular formula C27H26N4O9. The IR spectra of 8a,b and
9a,b contained absorption bands at 1210–1195 cmÀ 1 and 1380–1375 cmÀ 1 attributed
to sulphonyl group (SO2).
The IR and 13C NMR spectra of 10a,b and 11a,b showed the absence of the signal
due to thione (C = S) observed in 6a,b and 7a,b (Experimental). The b-configuration
and 4C1 conformation for these compounds were confirmed from 1H NMR data. A com-
parison of the 1H NMR parameters of sulphone derivative 9a with those of the S-glycoside

82
Saleh and Abdel-Megeed
Scheme 2. Proposed mass spectral cleavage pathway of compounds 4b and 6b.
derivative 5a, shows that the chemical shift for the signal of H-1’ (anomeric proton)
appears 0.39 ppm lower field than that of 5a (Experimental). The chemical shift of the
anomeric proton (H-1’) and anomeric carbon atom (C-1’) of the carbohydrate moiety for
10a resonated at higher field than N-glycoside[22] 6a in 1H and 13C NMR spectra,
respectively (Experimental).

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
83
Scheme 3. Oxidation of compounds 4–7 and deacetylation of compounds 10–13.
Attempts to deprotect S-glycoside derivatives 4, 5, 8 and 9 were carried out with
sodium methoxide in methanol resulting in its decomposition. Deprotection of nucleo-
side derivatives 6a,b, 7a,c, 10a and 11a,b under the same conditions gave the expected
deacetylated nucleosides 12a,b, 13a,b, 14a and 15a,b, respectively (Scheme 3). The
structures of new compounds were established for the reaction products based on their
analytical and spectral data (Experimental). The IR spectra of deacetylated nucleosides
are characterized by the absence of uC = O ester stretching vibration at 1755–1743 cmÀ 1
region and the presence of two strong bands at 1694–1672 and 3447–3435 cmÀ 1
region due to uC = O and uOH groups, respectively.
The b-configuration in the sugar moiety was assigned on the basis of the coupling
constant values of the anomeric proton, easily measurable in H NMR spectra of the
deacetylated nucleosides (Experimental).
1

84
Saleh and Abdel-Megeed
EXPERIMENTAL
Melting points were determined with a Buchi SMP-20 apparatus and are
uncorrected. IR spectra were recorded on a Unicam SP 1200 spectrophotometer using
1
KBr discs. H and 13C NMR spectra were recorded on a Varian CFT-20 operating 300
1
MHz for H and 100 MHz for 13C measurements. Tetramethylsilane (TMS) was used
as internal standard and chemical shifts are expressed in d-ppm values. Low-resolution
mass spectra were recorded on micromass spectrometer model 7070 F at energy 70 eV
and inlet temperature 90°C. FAB (LSIMS) spectra were recorded on a VG-Autospec
instrument. Analytical TLC was performed on EM silica gel 60 F254 sheet (0.2 mm)
with benzene/acetone (5:2, v/v) and in 2-propanol/benzene/25% ammonia (10:5:1,
v/v/v) as the developing eluents A and B. The spots were detected with UV lamp
model UV GL-58. [a]D were measured on a polarimeter SR-6 at 25°C in CHCl3.
Elemental analyses were obtained from the laboratory service of microanalysis, Tanta
University and from microanalysis center Cairo University, Cairo, Egypt.
4-Phenyl-1-thioxo [1,2,4] triazolo [4,3-a] quinazolin-5(4H)-one (2a). This
compound was obtained in 82% as previously described,[25] mp 320–322°C (Lit.[25]
310–315°C, without any spectral data), additional data, Rf = 0.45(solvent system A),
Rf = 0.72 (solvent system B); IR: 3434 (NH), 1211 (C = S), 1695 (C = O
1
quinazolinone) cmÀ 1, H NMR (DMSO-d6): dH 10.29 (s, 1H, NH disappeared with
D2O), 7.50–8.2(m, 9H, Ar-H), 13C NMR (DMSO-d6): dc 148.7 (C-3a), 163.8(C-5),
116.4(C-5a), 131.2(C-6), 129.9(C-7), 137.8(C-8), 119.7(C-9), 138.2(C-9a), 137.2(C-1 of
Ph), 129.8(2C, C-2,6 of Ph), 128.6(2C, C-3,5 of Ph), 129.3(C-4 of Ph), 165.2 (C = S);
MS (EI): m/z (%) 295(25.49, M + 1), 294(100, M + ), 261(14.92), 236(40.67),
221(7.22), 145(6.89), 118(8.43), 104(6.77).
1-Thioxo-4-(m-tolyl)[1,2,4] triazolo[4,3-a]quinazolin-5(4H)-one (2b). This
compound was obtained in 77% as previously reported[25]), mp 310–312°C (Lit.[25]
308–311°C, without any spectral data), additional data, Rf = 0.48 (solvent system A),
Rf = 0.75(solvent system B); IR: 3495 (NH), 1231(C = S), 1698 (C = O quinazo-
1
linone) cm À 1; H NMR (DMSO-d6): dH 11.12 (s, 1H, NH disappeared with D2O),
7.54–8.35 (m, 8H, Ar-H), 2.51(s, 3H, CH3, J = 7.2 Hz); 13C NMR (DMSO-d6): dc
149.7(C-3a), 162.1(C-5), 118.0(C-5a), 129.7(C-6), 131.3(C-7), 135.5(C-8), 125.4(C-9),
138.8(C-9a), 137.9(C-1 of Ph), 129.6(C-2 of Ph), 137.5(C-3 of Ph), 128.7(C-4 of Ph),
128.2(C-5 of Ph), 123.4(C-6 of Ph), 29.6(m-CH3), 165.2 (C = S); MS (EI): m/z (%)
309(100, M + + 1), 308 (83.65, M + ), 275 (42.55), 247(82.43), 232 (12.34),
162(25.32), 134(10.52), 118(15.0).
General procedure for the preparation of acetylated S-glycosides 4a–c, 5a–c
and acetylated N-glycosides 6a–c, 7a–c. To a suspension of anhydrous K2CO3 (4.6
g, 33.3 mmol) in 50 mL of dry acetone at room temperature was added 4-aryl-1-thioxo
[1,2,4] triazolo [4,3-a] quinazolin-5 (4H)-ones (2a,b) (5.6 mmol) and then (11.2 mmol)
of O-acetylated glycosyl bromides 3a–c and the reaction mixture was stirred for 10 h.
The precipitate (KBr) was filtered off, and the filtrate was concentrated to dryness. The
residue was dissolved in a 3:1 mixture of petroleum ether and acetone and transferred
to a 50 Â 2-cm column of silica gel (L 100/250 m). The product was eluted with a

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
85
mixture of petroleum ether and acetone, and the fractions containing N-glycosides 6
and 7 were collected. The fractions were monitored by TLC in system A. The sub-
sequent fractions contained S-glycosides 4 and 5. The following title compounds were
prepared as just described.
4-Phenyl-1-(2’,3’,4’,6’-tetra-O-acetyl-b-D-glucopyranosylthio)[1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (4a). This compound was obtained in 58% yield,
mp 215–217°C (from aqueous ethanol), Rf = 0.46 (solvent in system A), Rf = 0.78
25
(solvent in system B), [a]D + 52 (c 1.0, CHCl3); IR: 1746(C = O ester),
1686(C = O quinazolinone), 1628 cm À 1 (C = N); 1H NMR (CDCl3): dH 7.41–
8.22 (m, 9H, Ar-H), 5.82(d, 1H, b H-1’, J1’2’ = 9.2 Hz), 5.08(t, 1H, H-2’, J2’,3’ = 9.2
Hz), 5.36(t, 1H, H-3’, J3’,4’ = 9.0 Hz), 5.13(t, 1H, H-4’, J4’,5’ = 9.2 Hz), 3.95(m, 1H,
H-5’), 4.25(dd, 1H, H-6’, J6’,6@ = 12.4 Hz, J6’5’ = 3.3 Hz), 4.15(dd, 1H, H-6@,
J6@,5’ = 2.6 Hz) 2.09, 2.05, 2.01, 1.98(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc
150.1(C-3a), 160.3(C-5), 118.4(C-5a), 129.9(C-6), 127.4(C-7), 135.2(C-8), 116.8(C-9),
134.2(C-9a), 138.7(C-1 of Ph), 129.4(2C, C-2,6 of Ph), 128.9(2C, C-3,5 of Ph),
129.8(C-4 of Ph), 144.6 (C-S), 83.7(b C-1’), 71.2(C-2’), 72.3(C-3’), 68.2(C-4’),
75.2(C-5’), 63.1(C-6’), 20.4, 20.5 (2COCH3), 20.3(2COCH3), 170.2, 169.6, 169.2,
168.6 (4 COCH3).
Anal. Calcd for C29H27N4O10S (623.61): C, 55.85; H, 4.36; N, 8.98; S, 5.14.
Found: C, 55.63; H, 4.05; N, 8.67; S, 4.94.
4-Phenyl-1-(2’,3’,4’,6’-tetra-O-acetyl-b-D-galactopyranosylthio)[1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (4b). This compound was obtained in 53% yield,
mp 219–221°C (from ethanol), Rf = 0.47(solvent in system A), Rf = 0.78 (solvent in
25
system B), [a]D + 37 (c 1.0, CHCl3); IR: 1748(C = O ester), 1685(C = O
quinazolinone), 1631 cmÀ 1 (C = N); 1H NMR (CDCl3): dH 7.44–8.26 (m, 9H,
Ar-H), 5.86(d, 1H, bH-1’, J1’2’ = 10.2 Hz), 5.28(t, 1H, H-2’, J2’,3’ = 10.2 Hz), 5.21(t,
1H, H-3’, J3’,4’ = 3.4 Hz), 5.47(t, 1H, H-4’, J4’,5’ = 3.2 Hz), 4.19–4.09(m, 3H, H-5’, H-
6’, H-6@), 2.12, 2.02, 2.00, 1.98(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 150.5
(C-3a), 160.2(C-5), 118.4(C-5a), 129.7(C-6), 126.9(C-7), 134.7(C-8), 117.2(C-9),
134.0(C-9a), 138.6(C-1 of Ph), 129.2(2C, C-2,6 of Ph), 128.8(2C, C-3,5 of Ph),
129.9(C-4 of Ph), 144.5 (C-S), 82.8(b C-1’), 67.5(C-2’), 72.2(C-3’), 67.3(C-4’), 75.0(C-
5’), 63.4(C-6’), 20.7(2COCH3), 20.6 (2COCH3). 170.5, 169.6, 169.3, 168.6 (4 COCH3);
MS (FAB): m/z (%) 647 (22.8, [M + Na] + , 625 (77.0, [M + H] + , 295 (63.32,
B + 2), 294 (10.12, B + 1), 331(40.43, sugar moiety), 169 (100, C8H9O4 + ).
Anal. Calcd for C29H27N4O10S (623.61): C, 55.85; H, 4.36; N, 8.98; S, 5.14.
Found: C, 56.07; H, 4.08; N, 8.68; S, 5.32.
4-Phenyl-1-(2’,3’,4’-tri-O-acetyl-b-D-xylopyranosylthio)[1,2,4] triazolo[4,3-a]
quinazolin-5 (4H)-one (4c). This compound was obtained in 50% yield, mp 210–
212°C (from ethanol), Rf = 0.44(solvent in system A), Rf = 0.77 (solvent in system
25
B), [a]D + 64 (c 1.0, CHCl3); IR: 1745(C = O ester), 1688(C = O quinazolinone),
1
1627 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.39–8.25 (m, 9H, Ar-H), 5.84(d, 1H, b
H-1’, J1’2’ = 7.8 Hz), 4.98(t, 1H, H-2’, J2’,3’ = 7.5 Hz), 5.27(t, 1H, H-3’, J3’,4’ = 7.5
Hz), 4.84( m, 1H, H-4’, J4’,5’ = 4.6 Hz), 4.05 (dd, 1H, H-5’, J5’,5@ = 11.9 Hz), 3.73 (dd,
1H, H-5@, J4’,5@ = 7.4 Hz), 2.04, 2.00, 1.96 (each s, each 3H, 3Ac); MS (FAB): m/z (%)

86
Saleh and Abdel-Megeed
574 (14.45, [M + Na] + , 552 (48.37, [M + H]+ , 294 (17.93, B + 1), 259 (38.37, sugar
moiety), 221 (7.45), 145 (13.29), 118 (5.17), 76(14.34), 60 (100, AcOH).
Anal. Calcd for C26H23N4O8S (551.55): C, 56.62; H, 4.20; N, 10.16; S, 5.81.
Found: C, 56.89; H, 3.92; N, 9.84; S, 5.99.
1-(2’,3’,4’,6’-Tetra-O-acetyl-b-D-glucopyranosylthio)-4-(m-tolyl) [1,2,4]triazolo
[4,3-a] quinazolin-5 (4H)-one (5a). This compound was obtained in 62% yield, mp
207–209°C (from EtOAc)), Rf = 0.48 (solvent in system A), Rf = 0.81 (solvent in system
25
B), [a]D + 78 (c 1.0, CHCl3); IR: 1752(C = O ester), 1684(C = O quinazolinone),
1625 cmÀ 1 (C = N); 1H NMR (CDCl3): dH 7.38–8.25 (m, 8H, Ar-H), 2.47 (s, 3H, m-CH3,
J = 7.1 Hz), 5.80(d, 1H, b H-1’, J1’2’ = 9.2 Hz), 5.05(t, 1H, H-2’, J2’,3’ = 9.5 Hz), 5.33(t,
1H, H-3’, J3’,4’ = 10.4 Hz), 5.10(t, 1H, H-4’, J4’,5’ = 9.0 Hz), 3.91(m, 1H, H-5’), 4.21(dd,
1H, H-6’, J6’,6@ = 12.7 Hz, J6’5’ = 5.5 Hz), 4.13(dd, 1H, H-6@, J6’,6@ = 12.4 Hz, J6@,5’ = 2.5
Hz), 2.03, 2.01, 1.98, 1.95(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 149.7 (C-3a),
160.5(C-5), 117.9(C-5a), 129.6(C-6), 127.6(C-7), 135.0(C-8), 117.1(C-9), 135.2(C-9a),
136.4(C-1 of Ph), 129.6(C-2 of Ph), 138.5(C-3 of Ph), 129.3(C-4 of Ph), 128.6(C-5 of Ph),
126.1(C-6 of Ph), 21.3 (m-CH3), 144.2 (C-S), 82.4(b C-1’), 69.8(C-2’), 73.2(C-3’), 67.5(C-
4’), 74.4(C-5’), 61.9(C-6’), 20.6, 20.5, 20.3, 20.1 (4COCH3), 170.2, 169.3, 169.0, 168.2 (4
COCH3); MS (FAB): m/z (%) 661(24.25, ([M + Na] + ), 639 (39.41, [M + H]+ ), 331
(43.21, sugar moiety), 308 (100, B + 1), 275(21.13), 235 (4.45), 229 (5.33), 187 (3.85),
145 (6.75), 118 (5.17), 109 (68.54), 76(14.34).
Anal. Calcd for C30H29N4O10S (637.64): C, 56.51; H, 4.58; N, 8.79; S, 5.03.
Found: C, 55.68; H, 4.34; N, 9.00; S, 5.21.
1-(2’,3’,4’,6’-Tetra-O-acetyl-b-D-galactopyranosylthio)-4-(m-tolyl) [1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (5b). This compound was obtained in 60% yield, mp
202–204°C (from EtOAc), Rf = 0.48(solvent in system A), Rf = 0.84 (solvent in system
25
B), [a]D + 42 (c 1.0, CHCl3); IR: 1744(C = O ester), 1681(C = O quinazolinone),
1623 cmÀ 1 (C = N); 1H NMR (CDCl3): dH 7.35–8.23 (m, 8H, Ar-H), 2.45(s, 3H, CH3)
5.82(d, 1H, b H-1’, J1’2’ = 10.0 Hz), 5.24(t, 1H, H-2’, J2’,3’ = 10.2 Hz), 5.19(t, 1H, H-3’,
J3’,4’ = 3.4 Hz), 5.45(t, 1H, H-4’, J4’,5’ = 3.2 Hz), 4.18–4.03(m, 3H, H-5’, H-6’, H-6@),
2.10, 1.99, 1.98, 1.96(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 149.8 (C-3a), 160.3(C-
5), 118.2(C-5a), 129.2(C-6), 127.5(C-7), 135.2(C-8), 116.3(C-9), 135.3(C-9a), 135.9(C-1
of Ph), 129.4(C-2 of Ph), 138.3(C-3 of Ph), 129.4(C-4 of Ph), 128.7(C-5 of Ph), 126.3(C-6
of Ph), 21.6 (m-CH3), 144.3 (C-S), 81.9(b C-1’), 67.9(C-2’), 71.3(C-3’), 66.3(C-4’), 74.2(C-
5’), 61.8(C-6’), 20.4(2COCH3), 20.2(2COCH3), 169.7, 169.5, 169.3, 168.4 (4, COCH3).
Anal. Calcd for C30H29N4O10S (637.64): C, 56.51; H, 4.58; N, 8.79; S, 5.03.
Found: C, 56.78; H, 4.90; N, 8.46; S, 5.18.
1-(2’,3’,4’-Tri-O-acetyl-b-D-xylopyranosylthio)-4-(m-tolyl)[1,2,4] triazolo[4,3-a]
quinazolin-5 (4H)-one (5c). This compound was obtained in 59% yield, mp 232–
234°C (from EtOH), Rf = 0.46 (solvent in system A), Rf = 0.80 (solvent in system B),
25
[a]D + 37 (c 1.0, CHCl3); IR: 1743(C = O ester), 1682(C = O quinazolinone), 1624
1
cmÀ 1 (C = N); H NMR (CDCl3): dH 7.35–8.24 (m, 8H, Ar-H), 2.41 (s, 3H, m-CH3),
5.80(d, 1H, b H-1’, J1’2’ = 7.6 Hz), 4.96(t, 1H, H-2’, J2’,3’ = 7.5 Hz), 5.24(t, 1H, H-3’,
J3’,4’ = 7.4 Hz), 4.82( m, 1H, H-4’, J4’,5’ = 4.5 Hz), 4.03(dd, 1H, H-5’, J5’,5@ = 11.9
Hz), 3.66 (dd, 1H, H-5@, J4’,5@ = 7.6 Hz), 2.03, 2.02, 1.93 (each s, each 3H, 3Ac).

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
87
Anal. Calcd for C27H25N4O8S (565.57): C, 57.34; H, 4.46; N, 9.91; S, 5.67. Found:
C, 57.80; H, 4.77; N, 9.62; S, 5.78.
4-Phenyl-N2-(2’,3’,4’,6’-tetra-O-acetyl-b-D-glucopyranosyl)-1-thioxo-[1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (6a). This compound was obtained in 32% yield,
mp 193–195°C (from aqueous ethanol), Rf = 0.54 (solvent in system A), Rf = 0.84
25
(solvent in system B), [a]D + 38 (c 0.5, CHCl3); IR: 1747(C = O ester), 1692(C = O
1
quinazolinone), 1625 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.52–9.97 (m, 9H, Ar-H),
6.42(d, 1H, b H-1’, J1’2’ = 9.6 Hz), 5.53(t, 1H, H-2’, J2’,3’ = 9.6 Hz), 5.44(t, 1H, H-3’,
J3’,4’ = 9.6 Hz), 5.21(t, 1H, H-4’, J4’,5’ = 9.6 Hz), 3.92(m, 1H, H-5’), 4.37(dd, 1H, H-6’,
J6’,6@ = 12.6 Hz, J6’5’ = 3.8 Hz), 4.17(dd, 1H, H-6@, J6@,5’ = 2.6 Hz) 2.12, 2.08, 2.05,
1.96(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 147.4 (C-3a), 160.2(C-5), 117.8(C-5a),
129.5(C-6), 127.4(C-7), 134.6(C-8), 117.2(C-9), 136.4(C-9a), 138.5(C-1 of Ph), 128.8(2C,
C-2,6 of Ph), 129.0(2C, C-3,5 of Ph), 129.7(C-4 of Ph), 164.8 (C = S), 87.4(b C-1’),
71.5(C-2’), 73.8(C-3’), 69.4(C-4’), 73.9(C-5’), 62.3(C-6’), 20.7, 20.4(2COCH3),
20.3(2COCH3), 170.5, 169.8, 169.2, 168.5(4 COCH3).
Anal. Calcd for C29H27N4O10S (623.61): C, 55.85; H, 4.36; N, 8.98; S, 5.14.
Found: C, 56.09; H, 4.62; N, 9.19; S, 4.97.
4-Phenyl-N2-(2’,3’,4’,6’-tetra-O-acetyl-b-D-galactopyranosyl)-1-thioxo [1,2,4]
triazolo [4,3-a] quinazolin-5 (4H)-one (6b). This compound was obtained in 24%
yield, mp 202–204°C (from ethanol), Rf = 0.54 solvent in system A), Rf = 0.83
25
(solvent in system B), [a]D + 73 (c 0.5, CHCl3); IR: 1745(C = O ester), 1690
1
(C = O quinazolinone), 1628 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.52–9.96 (m,
9H, Ar-H), 6.38(d, 1H, b H-1’, J1’2’ = 9.6 Hz), 5.49(t, 1H, H-2’, J2’,3’ = 9.6 Hz), 5.19(t,
1H, H-3’, J3’,4’ = 4.0 Hz), 5.49(t, 1H, H-4’, J4’,5’ = 3.7 Hz), 4.35–4.17(m, 3H, H-5’, H-
6’, H-6@), 2.23, 2.06, 2.00, 1.98(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 146.8 (C-
3a), 160.4(C-5), 118.0(C-5a), 129.8(C-6), 127.4(C-7), 135.0(C-8), 117.1(C-9), 136.1(C-
9a), 138.3C-1 of Ph), 126.5(2C, C-2,6 of Ph), 128.5(2C, C-3,5 of Ph), 129.7(C-4 of
Ph), 164.8 (C = S), 86.4(b C-1’), 70.5 (C-2’), 73.0(C-3’), 68.4(C-4’), 74.4(C-5’), 62.3
(C-6’), 20.6(2COCH3), 20.5 (2COCH3). 170.4, 169.9, 169.0, 168.7 (4 COCH3); MS
(FAB): m/z (%) 647 (14.6, [M + Na] + , 625 (59.0, [M + H] + , 294 (27.53, B + 1),
331(22.84, sugar moiety), 169 (100, C8H9O4 + ).
Anal. Calcd for C29H27N4O10S (623.61): C, 55.85; H, 4.36; N, 8.98; S, 5.14.
Found: C, 55.67; H, 4.15; N, 8.69; S, 5.03.
4-Phenyl-N2-(2’,3’,4’-tri-O-acetyl-b-D-xylopyranosyl)-1-thioxo[1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (6c). This compound was obtained in 37% yield,
mp 192–194°C (from methanol), Rf = 0.52 (solvent in system A), Rf = 0.83 (solvent
25
in system B), [a]D + 33 (c 0.5, CHCl3); IR: 1744(C = O ester), 1692(C = O
quinazolinone), 1623 cmÀ 1 (C = N); 1H NMR (CDCl3): dH 7.42–9.95 (m, 9H,
Ar-H), 6.43(d, 1H, b H-1’, J1’2’ = 9.4 Hz), 5.03(t, 1H, H-2’, J2’,3’ = 9.4 Hz), 5.38(t,
1H, H-3’, J3’,4’ = 9.2 Hz), 4.86( m, 1H, H-4’, J4’,5’ = 4.3 Hz), 4.07 (dd, 1H, H-5’,
J5’,5 = 12.2 Hz), 3.78 (dd, 1H, H-5@, J4’,5@ = 8.1 Hz), 2.07, 2.04, 1.98 (each s, each
3H, 3Ac).
Anal. Calcd for C26H23N4O8S (551.55): C, 56.62; H, 4.20; N, 10.16; S, 5.81.
Found: C, 56.35; H, 4.52; N, 9.93; S, 5.96.

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Saleh and Abdel-Megeed
N2-(2’,3’,4’,6’-Tetra-O-acetyl-b-D-glucopyranosyl)-1-thioxo-4-(m-tolyl) [1,2,4]
triazolo [4,3-a] quinazolin-5 (4H)-one (7a). This compound was obtained in 32%
yield, mp 189–191°C (from aqueous ethanol), Rf = 0.56 (solvent in system A),
25
Rf = 0.85 (solvent in system B), [a]D + 68 (c 0.5, CHCl3); IR: 1755(C = O ester),
1
1694(C = O quinazolinone), 1631 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.60–9.98
(m, 8H, Ar-H), 2.45 (s, 3H, m-CH3, J = 7.1 Hz), 6.42(d, 1H, b H-1’, J1’2’ = 9.7 Hz),
5.52(t, 1H, H-2’, J2’,3’ = 9.7 Hz), 5.42(t, 1H, H-3’, J3’,4’ = 9.7 Hz), 5.20(t, 1H, H-4’,
J4’,5’ = 9.7Hz), 3.91(m, 1H, H-5’), 4.35(dd, 1H, H-6’, J6’,6@ = 12.3 Hz, J6’5’ = 3.6 Hz),
4.16(dd, 1H, H-6@, J6@,5’ = 2.2 Hz) 2.10, 2.06, 2.02, 1.96(each s, each 3H, 4Ac); 13C
NMR (CDCl3): dc 147.2 (C-3a), 160.0(C-5), 117.2(C-5a), 129.1(C-6), 127.8(C-7),
135.2(C-8), 117.3(C-9), 133.7(C-9a), 137.5(C-1 of Ph), 129.4(C-2of Ph), 138.3(C-3 of
Ph), 129.7(C-4 of Ph), 128.1(C-5 of Ph), 126.4(C-6 of Ph), 21.5 (m-CH3), 165.2
(C = S), 87.6(b C-1’), 73.5(C-2’), 72.4(C-3’), 70.2(C-4’), 73.8(C-5’), 61.7(C-6’), 20.5,
20.4, 20.3, 20.0 (4COCH3), 170.4, 169.9, 169.6, 169.4 (4 COCH3); MS (FAB): m/z (%)
661(18.35, [M + Na] + , 639 (59.0, [M + H] + , 308(17.32, B + 1), 331(31.62, sugar
moiety), 271 (6.21), 229(4.23), 109(100).
Anal. Calcd for C30H29N4O10S (637.64): C, 56.51; H, 4.58; N, 8.79; S, 5.03.
Found: C, 56.27; H, 4.28; N, 9.06; S, 5.21.
N2-(2’,3’,4’,6’-Tetra-O-acetyl-b-D-galactopyranosyl)-1-thioxo-4-(m-tolyl) [1,2,4]
triazolo [4,3-a] quinazolin-5 (4H)-one (7b). This compound was obtained in 29%
yield, mp 202–204°C (from ethanol), Rf = 0.55(solvent in system A), Rf = 0.86 (solvent
25
in system B), [a]D + 58 (c 0.5, CHCl3); IR: 1743(C = O ester), 1693(C = O qui-
nazolinone), 1624 cmÀ 1 (C = N); 1H NMR (CDCl3): dH 7.58–9.94 (m, 8H, Ar-H), 2.43
(s, 3H, m-CH3, J = 7.1 Hz), 6.40(d, 1H, b H-1’, J1’2’ = 10.3Hz), 5.47(t, 1H, H-2’,
J2’,3’ = 10.3 Hz), 5.22(t, 1H, H-3’, J3’,4’ = 3.8 Hz), 5.52(t, 1H, H-4’, J4’,5’ = 3.9 Hz), 4.33-
4.19(m, 3H, H-5’, H-6’, H-6@), 2.28, 2.02, 2.01, 2.00(each s, each 3H, 4Ac).
Anal. Calcd for C30H29N4O10S (637.64): C, 56.51; H, 4.58; N, 8.79; S, 5.03.
Found: C, 56.24; H, 4.93; N, 8.46; S, 4.92.
N2-(2’,3’,4’-Tri-O-acetyl-b-D-xylopyranosyl)-1-thioxo-4-(m-tolyl) [1,2,4]triazolo
[4,3-a] quinazolin-5 (4H)-one (7c). This compound was obtained in 28% yield, mp
213–215°C (from EtOAc)), Rf = 0.56 (solvent in system A), Rf = 0.87 (solvent in
25
system B), [a]D + 94 (c 0.5, CHCl3); IR: 1748(C = O ester), 1691(C = O
1
quinazolinone), 1629 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.58–9.96 (m, 8H, Ar-
H), 2.41 (s, 3H, m-CH3, J = 7.2 Hz), 6.42 (d, 1H, b H-1’, J1’2’ = 7.2 Hz), 5.05(t, 1H,
H-2’, J2’,3’ = 7.2 Hz), 5.41(t, 1H, H-3’, J3’,4’ = 7.2 Hz), 4.88(m, 1H, H-4’, J4’,5’ = 4.5
Hz), 4.09 (dd, 1H, H-5’, J5’,5@ = 11.5 Hz), 3.83 (dd, 1H, H-5@, J4’,5@ = 8.4 Hz), 2.09,
2.07, 2.03 (each s, each 3H, 3Ac).
Anal. Calcd for C27H25N4O8S (565.57): C, 57.34; H, 4.46; N, 9.91; S, 5.76. Found:
C, 57.17; H, 4.74; N, 9.69; S, 5.57.
Oxidation of S-glycosides 4a,b, 5a,c and N-glycosides 6a,b, 7a,b with m-
chloroperbenzoic acid. General procedure. A solution of substrate (50 mmol) and
m-chloroperbenzoic acid (0.270 g, 1.56 mmol) in dichloromethane (20 mL) was stirred
at room temperature for 5 h. The solution was filtered and washed with saturated
sodium bicarbonate (25 mL) followed by water (25 mL). The organic layer was dried
under anhydrous Na2SO4, filtered and concentrated to dryness under reduced pressure.

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
89
The residue was crystallized from methanol to yield sulphone derivatives 8a,b, 9a,b
and 1-oxo-derivatives 10a,b, 11a,b, respectively.
4-Phenyl-1-(2’,3’,4’,6’-tetra-O-acetyl-b-D-glucopyranosulfonyl)[1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (8a). This compound was obtained in 74% yield,
mp 189–192°C, Rf = 0.37(solvent in system A), Rf = 0.68 (solvent in system B),
25
[a]D + 36 (c 1.0, CHCl3); IR: 1744(C = O ester), 1689(C = O quinazolinone), 1632
(C = N) , 1375 and 1200 cmÀ 1 (SO2); 1H NMR (CDCl3): dH 7.32–8.14 (m, 9H,
Ar-H), 6.24(d, 1H, b H-1’, J1’2’ = 9.7 Hz), 5.51–5.27(m, 3H, H-2’, H-3’, H-4’), 3.47
(m, 1H, H-5’), 4.46(m, 2H, H-6’, H-6@) 2.15–2.00 (4 CH3); 13C NMR (CDCl3): dc
150.4(C-3a), 161.6(C-5), 118.7(C-5a), 130.2(C-6), 127.0(C-7), 135.6(C-8), 117.3(C-9),
135.4(C-9a), 138.6(C-1 of Ph), 129.5(2C, C-2,6 of Ph), 130.4(2C, C-3,5 of Ph),
129.6(C-4 of Ph), 146.2 (C-S), 83.6(b C-1’), 71.4(C-2’), 72.5(C-3’), 68.5(C-4’), 75.7
(C-5’), 63.4(C-6’), 20.6–20.2 (4COCH3), 170.6–169.2 (4 COCH3).
Anal. Calcd for C29H27N4O12S (655.61): C, 53.13; H, 4.15; N, 8.55; S, 4.89.
Found: C, 52.98; H, 3.82; N, 8.29; S, 4.71.
4-Phenyl-1-(2’,3’,4’,6’-tetra-O-acetyl-b-D-galactopyranosylsulfonyl) [1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (8b). This compound was obtained in 69 % yield,
mp 233–235°C, Rf = 0.36 (solvent in system A), Rf = 0.68 (solvent in system B),
25
[a]D + 29 (c 1.0, CHCl3); IR: 1746(C = O ester), 1685(C = O quinazolinone), 1629
(C =N), 1365 and 1198 cm À 1 (SO2).
Anal. Calcd for C29H27N4O12S (655.61): C, 53.13; H, 4.15; N, 8.55; S, 4.89.
Found: C, 52.90; H(C = N), 1380 and 1195 cm À 1 (SO2)., 4.47; N, 8.83; S, 5.10.
1-(2’,3’,4’,6’-Tetra-O-acetyl-b-D-glucopyranosylsulfonyl)-4-(m-tolyl) [1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (9a). This compound was obtained in 72% yield,
mp 207–209°C, Rf = 0.36 (solvent in system A), Rf = 0.70(solvent in system B),
25
[a]D + 59 (c 1.0, CHCl3); IR: 1748(C = O ester), 1692(C = O quinazolinone), 1628
(C = N), 1377 and 1210 cmÀ 1 (SO2); 1H NMR (CDCl3): dH 7.26–8.32 (m, 8H, Ar-H), 2.46
(s, 3H, m-CH3, J = 7.0 Hz), 6.29(d, 1H, b H-1’, J1’2’ = 9.7 Hz), 5.55–5.35(m, 3H, H-2’, H-
3’, H-4’), 3.98–4.54(m, 3H, H-5’, H-6’, H-6@), 2.16–2.03 (4 CH3); MS (FAB): m/z (%)
693(12.37, [M + Na] + , 671 (53.62, [M + H]+ , 308(8.45, B + 1), 331(100, sugar moiety).
Anal. Calcd for C30H29N4O12S (669.63): C, 53.81; H, 4.37; N, 8.37; S, 4.79.
Found: C, 53.67; H, 4.47; N, 8.06; S, 4.59.
1-(2’,3’,4’-Tri-O-acetyl-b-D-xylopyranosylsulfonyl)-4-(m-tolyl)[1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (9b). This compound was obtained in 74% yield,
mp 268–270°C, Rf =0.35(solvent in system A), Rf =0.72 (solvent in system B),
25
[a]D + 22 (c 1.0, CHCl3); IR: 1746(C = O ester), 1692(C = O quinazolinone),
1627(C =N), 1378 and 1198 cm À 1 (SO2).
Anal. Calcd for C27H25N4O10S (597.57): C, 54.27; H, 4.22; N, 9.38; S, 5.37.
Found: C, 54.04; H, 4.56; N, 9.11; S, 5.19.
1-Oxo-4-phenyl-N2-(2’,3’,4’,6’-tetra-O-acetyl-b-D-glucopyranosyl) [1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (10a). This compound was obtained in 76%
yield, mp 223–225°C, Rf = 0.38 (solvent in system A), Rf = 0.71 (solvent in system
25
B), [a]D + 48 (c 0.5, CHCl3); IR: 1749(C = O ester), 1690(C = O quinazolinone),

90
Saleh and Abdel-Megeed
1
1670 (C = O), 1625 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.37–9.32 (m, 9H, Ar-H),
5.92(d, 1H, b H-1’, J1’2’ = 10.2 Hz), 5.61(t, 1H, H-2’, J2’,3’ = 10.2 Hz), 5.56(t, 1H, H-
3’, J3’,4’ = 10.0 Hz), 5.26(t, 1H, H-4’, J4’,5’ = 10.2 Hz), 3.95(m, 1H, H-5’), 4.41(dd,
1H, H-6’, J6’,6@ = 12.3 Hz, J6’5’ = 3.9 Hz), 4.28(dd, 1H, H-6@, J6@,5’ = 2.8 Hz) 2.16,
2.10, 2.08, 2.00(each s, each 3H, 4Ac); 13C NMR (CDCl3): dc 147.8 (C-3a), 161.0(C-
5), 117.5(C-5a), 129.8(C-6), 127.7(C-7), 134.8(C-8), 117.6(C-9), 135.7(C-9a), 138.3(C-
1 of Ph), 128.6(2C, C-2,6 of Ph), 128.7(2C, C-3,5 of Ph), 129.5(C-4 of Ph), 153.3
(C = O), 84.3(b C-1’), 73.7 (C-2’), 73.2(C-3’), 70.8(C-4’), 69.3(C-5’), 62.8(C-6’), 21.2,
20.7 (2COCH3), 20.5(2COCH3), 171.3, 170.5, 169.7 169.0 (4 COCH3).
Anal. Calcd for C29H27N4O11 (607.55): C, 57.33; H, 4.48; N, 9.22. Found: C,
57.09; H, 4.83; N, 8.91.
1-Oxo-4-phenyl-N2-(2’,3’,4’,6’-tetra-O-acetyl-b-D-galactopyranosyl) [1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (10b). This compound was obtained in 64%
yield, mp 254–256°C Rf = 0.36 solvent in system A), Rf = 0.72 (solvent in system
25
B), [a]D + 39 (c 0.5, CHCl3); IR: 1746(C = O ester), 1690(C = O quinazolinone),
1675 (C = O), 1624 cmÀ 1 (C = N); 13C NMR (CDCl3): dc 147.4 (C-3a), 160.8(C-5),
118.1(C-5a), 129.5(C-6), 128.2(C-7), 134.5(C-8), 117.5(C-9), 135.6(C-9a), 137.7(C-1 of
Ph), 128.6(2C, C-2,6 of Ph), 128.7(2C, C-3,5 of Ph), 129.5(C-4 of Ph), 152.7 (C = O),
85.7(b C-1’), 72.5(C-2’), 73.0(C-3’), 72.4(C-4’), 68.6(C-5’), 62.4(C-6’), 21.3–2.00
(4COCH3), 170.6–168.7 (4 COCH3).
Anal. Calcd for C29H27N4O11 (607.55): C, 57.33; H, 4.48; N, 9.22. Found: C,
57.08; H, 4.22; N, 8.93.
1-Oxo-N2-(2’,3’,4’,6’-tetra-O-acetyl-b-D-glucopyranosyl)-4-(m-tolyl) [1,2,4] tria-
zolo [4,3-a] quinazolin-5 (4H)-one (11a). This compound was obtained in 79% yield,
mp 258–261°C, Rf = 0.38 (solvent in system A), Rf = 0.73 (solvent in system B),
25
[a]D + 85 (c 0.5, CHCl3); IR: 1752(C = O ester), 1690(C = O quinazolinone), 1680
1
(C = O), 1629 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.48–9.62 (m, 8H, Ar-H), 2.48
(s, 3H, m-CH3, J = 7.0 Hz), 5.90(d, 1H, b H-1’, J1’2’ = 8.4 Hz), 5.58(t, 1H, H-2’,
J2’,3’ = 8.4 Hz), 5.48(t, 1H, H-3’, J3’,4’ = 8.6 Hz), 5.31(t, 1H, H-4’, J4’,5’ = 8.4Hz),
3.94(m, 1H, H-5’), 4.42(dd, 1H, H-6’, J6’,6@ = 12.6 Hz, J6’5’ = 3.8 Hz), 4.21(dd, 1H, H-
6@, J6@,5’ = 2.5 Hz) 2.21, 2.08, 2.06, 2.02(each s, each 3H, 4Ac).
Anal. Calcd for C30H29N4O11 (621.58): C, 57.97; H, 4.70; N, 9.01. Found: C,
57.71; H, 4. 39; N, 8.70
1-Oxo-N2-(2’,3’,4’-Tri-O-acetyl-b-D-xylopyranosyl)-4-(m-tolyl) [1,2,4] triazolo
[4,3-a] quinazolin-5 (4H)-one (11b). This compound was obtained in 75% yield,
mp 297–300°C, Rf = 0.35(solvent in system A), Rf = 0.74 (solvent in system B),
25
[a]D + 115 (c 0.5, CHCl3); IR: 1753(C = O ester), 1689(C = O quinazolinone),
1
1675 (C = O), 1625 cmÀ 1 (C = N); H NMR (CDCl3): dH 7.58–9.96 (m, 8H, Ar-H),
2.45 (s, 3H, m-CH3, J = 7.0 Hz), 5.89(d, 1H, b H-1’, J1’2’ = 9.3 Hz), 5.18(t, 1H, H-2’,
J2’,3’ = 9.3 Hz), 5.46(t, 1H, H-3’, J3’,4’ = 9.0 Hz), 4.83( m, 1H, H-4’, J4’,5’ = 4.8 Hz),
4.17 (dd, 1H, H-5’, J5’,5@ = 12.2 Hz), 3.90 (dd, 1H, H-5@, J4’,5@ = 9.0 Hz), 2.10, 2.08,
2.06 (each s, each 3H, 3Ac), 13C NMR (CDCl3): dc 147.6 (C-3a), 161.5 (C-5), 117.4(C-
5a), 128.6(C-6), 127.6(C-7), 135.4(C-8), 117.8(C-9), 134.0(C-9a), 137.7(C-1 of Ph),
128.8(C-2of Ph), 138.4(C-3 of Ph), 129.6(C-4 of Ph), 128.0(C-5 of Ph), 126.7(C-6 of

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
91
Ph), 21.7 (m-CH3), 154.3(C = O), 84.8(b C-1’), 73.5(C-2’), 72.7(C-3’), 70.4(C-4’),
62.2(C-6’), 21.0, 20.7, 20.5 (3COCH3), 171.0, 170.3, 169.4 (3 COCH3); MS (FAB): m/z
(%) 573 (26.42, [M + Na] + , 551 (100, [M + H]+ , 292(11.12, B + 1), 259(53.15, sugar
moiety), 235 (5.32), 145(12.15), 118(4.85).
Anal. Calcd for C27H25N4O9 (549.51): C, 59.01; H, 4.59; N, 10.20. Found: C,
58.72; H, 4.27; N, 10.48.
General deacetylation method. The acetylated product (3.5 mmol) was
dissolved in 25 mL of anhydrous methanol, then 1.5 mL of a 1 N NaOMe methanolic
solution were added. The reaction mixture was kept at room temperature for the
appropriate time (20–30 min.). The process was controlled by TLC (system B) until
total deacylation of starting material. The reaction mixture was neutralized with ion-
exchange resin Dowex-50 (H + form) to pH 6–7. The solution was filtered, the filtrate
was concentrated to dryness under reduced pressure and the residue was recrystallized
from absolute ethanol. The following products were prepared in this manner.
N2-(b-D-Glucopyranosyl)-4-phenyl-1-thioxo[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (12a). This compound was obtained in 83% yield, mp 274–275°C,
25
Rf = 0.52(solvent in system B), [a]D + 18 (c 0.8, CHCl3); IR: 3443(OH),
1
1687(C = O quinazolinone), 1628 cmÀ 1 (C = N); H NMR (DMSO-d6): dH 7.48–
9.24 (m, 9H, Ar-H), 5.41(d, 1H, b H-1’, J1’2’ = 9.3 Hz), 3.27–4.45(m, 6H, H-2’, H-3’, H-
4’, H-5’, H-6’, H-6@), 4.60 (brs, 1H, D2O exch., OH), 4.80–5.60 (m, 3H, D2O exch., OH);
13C NMR (DMSO-d6): dc 146.2 (C-3a), 160.4(C-5), 117.4(C-5a), 128.8(C-6), 127.6(C-7),
134.3(C-8), 117.3(C-9), 136.4(C-9a), 138.0(C-1 of Ph), 128.5(2C, C-2,6 of Ph), 129.2(2C,
C-3,5 of Ph), 129.2(C-4 of Ph), 163.9 (C = S), 84.8(b C-1’), 74.6(C-2’), 78.2(C-3’),
72.8(C-4’), 79.1(C-5’), 61.8(C-6’),); MS (FAB): m/z (%) 479(100, [M + Na] + .
Anal. Calcd for C21H20N4O6S (456.47): C, 55.26; H, 4.42; N, 12.27; S, 7.02.
Found: C, 54.97; H, 4.09; N, 11.99; S, 6.78.
N2-(b-D-Galactopyranosyl)-4-phenyl-1-thioxo[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (12b). This compound was obtained in 74% yield, mp 289–291°C,
25
Rf = 0.51(solvent in system B), [a]D + 26 (c 0.8, CHCl3); IR: 3440(OH),
1
1689(C = O quinazolinone), 1631 cm À 1 (C = N); H NMR (DMSO-d6): dH 7.47–
9.28 (m, 9H, Ar-H), 5.42(d, 1H, b H-1’, J1’2’ = 10.3 Hz), 3.25–4.42(m, 6H, H-2’, H-3’,
H-4’, H-5’, H-6’, H-6@), 4.58 (brs, 1H, D2O exch., OH), 4.76–5.58 (m, 3H, D2O exch.,
OH); 13C NMR (DMSO-d6): dc 146.2 (C-3a), 160.5(C-5), 117.4(C-5a), 129.0(C-6),
127.6(C-7), 134.5(C-8), 117.2(C-9), 136.4(C-9a), 138.2(C-1 of Ph), 128.6(2C, C-2,6 of
Ph), 129.2(2C, C-3,5 of Ph), 129.2(C-4 of Ph), 164.1 (C = S), 84.3 (b C-1’), 73.8(C-2’),
78.4(C-3’), 71.6(C-4’), 79.6(C-5’), 62.9(C-6’),); MS (FAB): m/z (%) 457(100, [M + H] + .
Anal. Calcd for C21H20N4O6S (456.47): C, 55.26; H, 4.42; N, 12.27; S, 7.02.
Found: C, 54.93; H, 4.22; N, 11.93; S, 7.24.
N2-(b-D-Glucopyranosyl)-1-thioxo-4-(m-tolyl)[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (13a). This compound was obtained in 89% yield, mp 229–230°C, (solvent,
25
Rf =0.55 (solvent in system B), [a]D + 27 (c 0.8, CHCl3); IR: 3439(OH), 1694(C = O
quinazolinone), 1631 cmÀ 1 (C =N); 1H NMR (DMSO-d6): dH 7.52–9.27 (m, 8H,
Ar-H), 2.47 (s, 3H, m-CH3, J= 7.2 Hz), 5.40(d, 1H, b H-1’, J1’2’ = 10.5 Hz), 3.35–4.43

92
Saleh and Abdel-Megeed
(m, 6H, H-2’, H-3’, H-4’, H-5’, H-6’, H-6@), 4.40 (brs, 1H, D2O exch., OH), 5.00–5.60
(m, 3H, D2O exch., OH); 13C NMR (DMSO-d6): dc 147.5 (C-3a), 160.4(C-5), 117.3(C-
5a), 128.6(C-6), 127.6(C-7), 135.6(C-8), 117.5(C-9), 134.0(C-9a), 137.4(C-1 of Ph),
129.7(C-2of Ph), 138.7(C-3of Ph), 129.9(C-4 of Ph), 128.2(C-5 of Ph), 126.7(C-6
of Ph), 21.8(m-CH3), 164.8 (C = S), 84.3(b C-1’), 74.6(C-2’), 78.5(C-3’), 72.4(C-4’),
79.4(C-5’), 62.3 (C-6; MS (FAB): m/z (%) 493(100, [M + Na] + .
Anal. Calcd for C22H22N4O6S (470.49): C, 56.16; H, 4.71; N, 11.91; S, 6.81.
Found: C, 56.42; H, 4.94; N, 11.65; S, 6.58.
N2-(b-D-Xylopyranosyl)-1-thioxo-4-(m-tolyl)[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (13b). This compound was obtained in 80% yield, mp 315–316°C,
25
Rf = 0.54 (solvent in system B), [a]D + 37 (c 0.8, CHCl3); IR: 4435(OH),
1
1687(C = O quinazolinone), 1629 cmÀ 1 (C = N); H NMR (DMSO-d6): dH 7.53–
9.24 (m, 8H, Ar-H), 2.47 (s, 3H, m-CH3, J = 7.0 Hz), 5.45(d, 1H, b H-1’, J1’2’ = 8.2 Hz),
3.18–4.52(m, 5H, H-2’, H-3’, H-4’, H-5’, H-5@), 4.47 (brs, 1H, D2O exch., OH), 5.00–
5.68 (m, 2H, D2O exch., OH); 13C NMR (DMSO-d6): dc 147.4 (C-3a), 160.6(C-5),
117.8(C-5a), 129.5(C-6), 128.0(C-7), 135.2(C-8), 117.3(C-9), 133.7(C-9a), 137.5(C-1
of Ph), 129.4(C-2of Ph), 138.5(C-3 of Ph), 129.8(C-4 of Ph), 128.5(C-5 of Ph),
126.4(C-6 of Ph), 21.8 (m-CH3), 164.3 (C = S), 84.8(b C-1’), 74.5(C-2’), 78.4(C-3’),
72.5(C-4’), 65.3(C-5’); MS (FAB): m/z (%) 463 (54.30, [M + Na] + , 441 (100,
[M + H] + .
Anal. Calcd for C21H20N4O5S (440.47): C, 57.26; H, 4.58; N, 12.72; S, 7.28.
Found: C, 56.94; H, 4.86; N, 12.41; S, 7.45.
N2-(b-D-Glucopyranosyl)-1-oxo-4-phenyl[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (14a). This compound was obtained in 68% yield, mp 313–315°C,
25
Rf = 0.54 (solvent in system B), [a]D + 19 (c 0.8, CHCl3); IR: 3445(OH), 1685(C =O
1
quinazolinone), 1672 (C = O), 1628 cmÀ 1 (C = N); H NMR (DMSO-d6): dH 7.42–
9.10 (m, 9H, Ar-H), 4.73(d, 1H, b H-1’, J1’2’ = 8.7 Hz), 3.37–4.49 (m, 6H, H-2’, H-3’,
H-4’, H-5’, H-6’, H-6@), 4.64 (brs, 1H, D2O exch., OH), 4.91–5.67 (m, 3H, D2O exch.,
OH); 13C NMR (DMSO-d6): dc 146.6 (C-3a), 160.7(C-5), 117.9(C-5a), 129.2(C-6),
127.8(C-7), 134.7(C-8), 117.5 (C-9), 136.8(C-9a), 138.4(C-1 of Ph), 128.6(2C, C-2,6 of
Ph), 129.7(2C, C-3,5 of Ph), 129.6(C-4 of Ph), 153.3 (C = O), 81.4 (b C-1’), 74.2(C-
2’), 78.8(C-3’), 73.6(C-4’), 79.5(C-5’), 62.4(C-6’),); MS (FAB): m/z (%) 463(100,
[M + Na] + .
Anal. Calcd for C21H20N4O7 (440.41): C, 57.27; H, 4.58; N, 12.72. Found: C,
57.54; H, 4.87; N, 12.37.
N2-(b-D-Glucopyranosyl)-1-oxo-4-(m-tolyl)[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (15a). This compound was obtained in 72% yield, mp 328–330°C, (solvent,
25
Rf = 0.57 (solvent in system B), [a]D + 39 (c 0.8, CHCl3); IR: 3446(OH),
1
1694(C = O quinazolinone), 1675 (C = O), 1631 cmÀ 1 (C = N); H NMR (DMSO-
d6): dH 7.47–9.12 (m, 8H, Ar-H), 2.43 (s, 3H, m-CH3, J = 7.0 Hz), 4.80(d, 1H, b H-1’,
J1’2’ = 9.4 Hz), 3.40–4.54 (m, 6H, H-2’, H-3’, H-4’, H-5’, H-6’, H-6@), 4.47 (brs, 1H, D2O
exch., OH), 5.25–5.63 (m, 3H, D2O exch., OH); 13C NMR (DMSO-d6): dc 147.7 (C-3a),
161.0(C-5), 117.5(C-5a), 128.3(C-6), 127.6(C-7), 135.6(C-8), 117.5(C-9), 134.0(C-9a),
137.4(C-1 of Ph), 130.1(C-2of Ph), 138.4(C-3of Ph), 129.4(C-4 of Ph), 128.6(C-5 of Ph),

4-Aryl-1-thioxo[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
93
126.8(C-6 of Ph), 21.7(m-CH3), 153.8 (C = O), 82.5(b C-1’), 73.2(C-2’), 77.9(C-3’),
73.6(C-4’), 79.7(C-5’), 62.8 (C-6; MS (FAB): m/z (%) 477(100, [M + Na] + .
Anal. Calcd for C22H22N4O7 (454.43): C, 58.15; H, 4.88; N, 12.33. Found: C,
57.84; H, 5.08; N, 12.62.
N2-(b-D-Xylopyranosyl)-1-oxo-4-(m-tolyl)[1,2,4]triazolo[4,3-a] quinazolin-5
(4H)-one (15b). This compound was obtained in 80% yield, mp 355–356°C,
25
Rf = 0.57 (solvent in system B), [a]D + 50 (c 0.8, CHCl3); IR: 3447(OH),
1
1689(C =O quinazolinone), 1675 (C = O), 1627 cmÀ 1 (C =N); H NMR (DMSO-d6):
dH 7.48–9.15 (m, 8H, Ar-H), 2.44 (s, 3H, m-CH3, J = 7.0 Hz), 4.82(d, 1H, b H-1’,
J1’2’ = 7.9 Hz), 3.28–4.50(m, 5H, H-2’, H-3’, H-4’, H-5’, H-5@), 4.46 (brs, 1H, D2O
exch., OH), 5.18–5.65 (m, 2H, D2O exch., OH); 13C NMR (DMSO-d6): dc 147.7 (C-3a),
161.3(C-5), 117.6(C-5a), 128.5(C-6), 127.3(C-7), 135.7(C-8), 117.5(C-9), 134.2(C-9a),
137.6(C-1 of Ph), 130.0(C-2 of Ph), 138.5(C-3 of Ph), 129.5(C-4 of Ph), 128.7(C-5 of
Ph), 126.9(C-6 of Ph), 21.7 (m-CH3), 153.7 (C = O), 82.4(b C-1’), 73.3(C-2’),77.8(C-
3’), 73.0(C-4’), 64.6(C-5’); MS (FAB): m/z (%) 425 (100, [M + H] + .
Anal. Calcd for C21H20N4O6 (424.41): C, 59.43; H, 4.75; N, 13.20. Found: C,
59.67; H, 4.94; N, 12.87.
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ReceivedApril 19, 2002
AcceptedJanuary 23, 2003