Synthesis of 2-(Substituted benzylideneamino)-4-(4'-hydroxyphenyl) thiazoles and their O-glucosides

Article abstract of DOI:10.1080/07328303.2010.497589

2-Amino-4-(4'-hydroxyphenyl) thiazole 1a was prepared from reaction between p-hydroxyacetophenone, thiourea, and iodine; compound 1a was treated with several (aryl/hetro aryl) aldehydes to form 2-(substituted benzylideneamino)-4- (4'-hydroxyphenyl) thiazo

Full text of DOI:10.1080/07328303.2010.497589

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Synthesis of 2-(Substituted
Benzylideneamino)-4-(4′-hydroxyphenyl)
Thiazoles and Their O-Glucosides
V. S. Taile a , V. N. Ingle a & K. M. Hatzade a b
a Department of Chemistry , Rashtrasant Tukadoji Maharaj Nagpur
University , Nagpur, 440 033, India
b Department of Chemistry , Dhote Bandhu Science College ,
Gondia, 441 614
Published online: 08 Sep 2010.
To cite this article: V. S. Taile , V. N. Ingle & K. M. Hatzade (2010) Synthesis of 2-(Substituted
Benzylideneamino)-4-(4′-hydroxyphenyl) Thiazoles and Their O-Glucosides, Journal of Carbohydrate
Chemistry, 29:5, 207-221, DOI: 10.1080/07328303.2010.497589
To link to this article: http://dx.doi.org/10.1080/07328303.2010.497589
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Journal of Carbohydrate Chemistry, 29:207–221, 2010
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Copyright Taylor & Francis Group, LLC
ISSN: 0732-8303 print / 1532-2327 online
DOI: 10.1080/07328303.2010.497589
Synthesis of 2-(Substituted
Benzylideneamino)-4-(4ꢁ-
hydroxyphenyl) Thiazoles
and Their O-Glucosides
V. S. Taile,1 V. N. Ingle,1 and K. M. Hatzade1,2
1Department of Chemistry, Rashtrasant Tukadoji Maharaj Nagpur University,
Nagpur-440 033, India
2Department of Chemistry, Dhote Bandhu Science College, Gondia-441 614
2-Amino-4-(4ꢁ-hydroxyphenyl) thiazole 1a was prepared from reaction between p-
hydroxyacetophenone, thiourea, and iodine; compound 1a was treated with sev-
eral (aryl/hetro aryl) aldehydes to form 2-(substituted benzylideneamino)-4-(4ꢁ-
hydroxyphenyl) thiazoles 2a–j, which were glucosylated by using acetobromoglucose as
a glucosyl donor to afford 2-(substituted benzylideneamino)-4-(2, 3, 4, 6-tetera-o-acetyl-
4ꢁ-o-β-D-glucosidoxyphenyl) thiazoles 3a–j, which further on during deacetylation pro-
duced 2-(substituted benzylideneamino)-4-(4ꢁ-o-β-D-glucosidoxyphenyl) thiazoles 4a–j.
These compounds were evaluated for biological activity, and their structure was con-
firmed by IR, NMR, mass spectra, elemental, and chemical analysis.
OH
H
H
O
HO
HO
HO
O
H
OH
H
N
H
N
N CH
R
S
N CH
R
S
Keywords Thiazole; Azomethine; Acetobromoglucose; o-Glucoside; Deacetylation
INTRODUCTION
Thiazole derivatives are of considerable interest from a therapeutic point of
view because of their wide spectrum of activity that includes antibacterial,
Received March 5, 2010; accepted May 17, 2010.
Address correspondence to V.S. Taile, Department of Chemistry, Rashtrasant Tukadoji
Maharaj Nagpur University, Nagpur-440 033, India. E-mail: vijaytaile@gmail.com
207

V.S. Taile et al.
208
antifungal, antitumor, anthelmintic, local anesthetic, diuretic, and anti-
inflammatory activities.[1–7] The thiazole nucleus forms an important part
of the structure of many therapeutic agents of diverse activities. 2-Amino-
thiazole possesses potent antiplatelet activity,[8] which is a good antidote for
barbiturate poisoning.[9] o-Glucosides are widely distributed throughout the
plant kingdom, especially in roots, leaves, seeds, and barks of plants, and
have good medicinal activity.[10–17] In O-glucosides, the carbohydrate residue
is termed the glycone, and the compound ROH, from which the carbohydrate
residue has been cleaved, is termed the aglycon. One of the most important
roles of o-glucoside is to increase the water solubility of organic compounds
and decrease toxicity of the aglycon portion. For the glucosylation of com-
pounds the mostly preferred method is the Koenigs-Knorr method.[18] We syn-
thesized the o-glucosylation by using the modified Michael method.[19] The
presence of imino group >C N is mainly responsible for the potent biologi-
cal activity of compounds. These azomethines constitute one of the most active
classes of compounds possessing diversified biological applications.[20–24] So,
in continuation of our research work[25–30] and keeping in mind the various
biological activities of thiazole, azomethine, and glucose moiety, we synthe-
sized worthwhile 2-(substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thia-
zoles and their o-glucosides; similarly, we studied their biological properties to
investigate whether they are associated with therapeutic properties.
RESULTS AND DISCUSSION
The sequence of the reaction, starting from the preparation of the aglycon moi-
ety, which was prepared from condensation between p-hydroxyacetophenone,
thiourea, and iodine, gives 2-amino-4-(4ꢁ-hydroxyphenyl) thiazole 1a; infrared
spectrum of the compound shows the following characteristic bands at 3487.8
( OH) due to the presence of a free phenolic hydroxyl group, 3379.5 ( NH2),
1
3127.7 (aromatic compound stretching), and 1600 (C C), and H NMR 6.4 (s,
1H, Thiazole), 6.8–7.8 (m, 4H, Ar H), 4.8 (bs, 2H, NH2), and 5.6 (s, 1H, OH).
Schiff base was prepared by condensation between 1a and various substituted
aldehydes to form 2-(substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thi-
azoles 2a–j (Scheme 1).
Acetobromoglucose (ACBG) acts as a glucosyl donor; it was prepared
by reaction of glucose pentacetate with brominating agent and extracting
the compound in chloroform.[31] 2-(Substituted benzylideneamino)-4-(4ꢁ-
hydroxyphenyl) thiazoles 2a–j were glucosylated by using acetobromoglu-
cose to afford 2-(substituted benzylideneamino)-4-(2, 3, 4, 6-tetra-o-acetyl-
4ꢁ-o-β-D-glucosidoxyphenyl) thiazoles 3a–j. The compound was obtained in
good yield; the deacetylation of 2-(substituted benzylideneamino)-4-(2, 3, 4, 6-
tetra-o-acetyl-4ꢁ-o-β-D-glucosidoxyphenyl) thiazoles 3a–j formed 2-(substituted
benzylideneamino)-4-(4ꢁ-o-β-D-glucosidoxyphenyl) thiazoles 4a–j; o-Glucoside

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
209
HO
HO
NH2
S
Iodine
N
+
CH3
2
H2N
C
O
NH2
S
1a
R-CHO
H2SO4
HO
N
N
CH
R
R
S
2a-j
a. Phenyl
b. p-Chloro aryl c. p-Methoxy
d. m-Nitro
e. p-Fluoro
aryl
aryl
aryl
f.
g.
h.
i.
j.
N
N
O
N
H
N
Scheme 1: Synthesis of 2-(substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles.
formation follows an SN2 mechanism; and the stereochemistry observed is
1,2-trans type in most of the cases reported, as a consequence of neighbor-
ing group participation. When the protecting group is acetate at C-2, there is
an intramolecular nucleophilic displacement of the leaving group, generating
an orthoester,[32] only β-anomer is the preferred product. 1H NMR of the com-
pound displayed the signal due to sugar protons between δ 3.2 and 4.50 ppm
and aromatic ring proton between δ 6.8 and 7.75 ppm. The β-glucosidic bond
formation was established by the appearance of doublet at δ 5.00–6.00 ppm
and coupling constant between 8.0 and 9.0 Hz. Electronic mass spectra also
confirmed the molecular weight of the compounds and 13C NMR spectrum; C-
1 resonated downfield of the other glucosyl carbon at δ 101–106.0, consistent
with the formation of o-β-glucosides (Scheme 2).
BIOLOGICAL ASSAY
The selected compounds from aglycons and o-glucosides were screened for their
antibacterial activities against various pathogenic bacteria—Escherichia coli,
Klebsiella aerogens, Staphylococcus aureus, and Bacillus subtilis—by the cup
plate diffusion of 100 µg/mL by using standard ciprofloxacin and sulphac-
etamide (100 µg/mL) for bacteria. Similarly, compounds were screened for an-
tifungal activity tested at 100 µg/mL concentration in methanol against As-
pergillus niger and Candida albicans, which were compared with the standard
drugs gentamicin and clotrimazole. The zone of inhibition was after 7 days at

V.S. Taile et al.
210
HO
+K-O
N
N
i
CH
R
N
N
CH R
S
S
2a-j
OAc
ii
H
H
O
AcO
AcO
O
H
H
OAc
H
N
CH
R
N
S
3a-j
OH
H
H
O
iii
HO
HO
O
H
OH
H
H
N
CH
R
N
S
4a-j
R
a. Phenyl
b. p-Chloro
c. p-Methoxy
d. m-Nitro
e. p-Fluoro
aryl
aryl
aryl
aryl
f.
g.
h.
i.
j.
N
N
O
N
H
N
Scheme 2: Synthetic of 2-(substituted benzylideneamino)-4-(4ꢁ-o-β-D-glucosidoxyphenyl)
thiazoles: (i) CH3OH, KOH; (ii) acetone, α-acetobromoglucose; (iii) CH3ONa,CH3OH.
37◦C for antifungal and 24 h of incubation at 37◦C for antimicrobial activity.
Most of the compounds exhibited mild to moderate antibacterial activity as
well as antifungal activity against all the microbes tested. Out of all the tested
compounds, the following compounds were found most active against the noted
bacteria and fungi: 2a (A. niger), 2e (K. aerogens, C. albicans), 4a (C. albicans,
A. niger), 4e (K. aerogens, B. subtilis, C. albicans), 4g (C. albicans, A. niger). A
biological activity result revealed that O-glucosides showed more pharmaceu-
tical activity than the aglycon (Table 1).
EXPERIMENTAL
The melting points (mp) are taken by using the open capillary method and are
uncorrected. The FT-IR spectra were recorded on a Perkin Elmer spectropho-
tometer using KBr disc. The 1H NMR spectra were recorded on a Bruker DRX-
300 (300 MHz FT-NMR) instrument using DMSO-d6 as a solvent and TMS as
internal standard, and the chemical shifts are expressed in δ ppm values. EI-
MS spectra were recorded by direct insertion technique with a Hitachi Perkin

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
211
Table 1: Zone of inhibitiona (mm) (activity index)std
Antibacterial Activity
Gram positive
Gram negative
Antifungal Activity
Compd
Nob
S. aureus B. subtilis
E. coli K. aerogens C. albicans
A. niger
2a
2b
2e
2f
12(0.35)∗ 10(0.34)∗
9(0.35)∗
(0.31)#
15(0.68)∗
(0.71)#.
13(0.59)∗
(0.61)#
18(0.85)∗
(0.78)#
25(1.00)∗
(1.04)#
(0.38)#
(0.38)#
16(0.47)∗ 12(0.41)∗ 16(0.45)∗
14(0.66)∗
(0.60)#
19(0.76)∗
(0.79)#
(0.51)#
21(0.61)∗ 21(0.72)∗ 17(0.48)∗
(0.67)# (0.80)# (0.58)#
20(0.58)∗ 25(0.86)∗ 18(0.51)∗
(0.64)# (0.96)# (0.62)#
18(0.52)∗ 19(0.65)∗ 14(0.40)∗
(0.58)# (0.73)# (0.48)#
14(0.41)∗ 10(0.34)∗ 12(0.34)∗
(0.45)# (0.38)# (0.41)#
15(0.44)∗ 12(0.41)∗ 14(0.40)∗
(0.48)# (0.46)# (0.48)#
17(0.50)∗ 15(0.51)∗ 18(0.51)∗
(0.54)# (0.57)# (0.62)#
20(0.58)∗ 25(0.86)∗ 19(0.54)∗
(0.64)# (0.96)# (0.65)#
22(0.64)∗ 29(1.00)∗ 20(0.57)∗
(0.70)# (1.15)# (0.68)#
21(0.61)∗ 20(0.68)∗ 18(0.51)∗
(0.67)# (0.76)# (0.62)#
(0.46)#
(0.55)#
21(0.95)∗
(1.00)#
20(0.95)∗
(0.86)#
14(0.56)∗
(0.58)#
21(0.95)∗
(1.00)#
12(0.57)∗
(0.52)#
11(0.44)∗
(0.45)#
2g
2j
15(0.68)∗
(0.71)#
18(0.85)∗
(0.78)#
20(0.80)∗
(0.83)#
15(0.68)∗
(0.71)#
12(0.57)∗
(0.52#
14(0.56)∗
(0.58)#
4a
4b
4e
4f
16(0.72)∗
(0.76)#.
14(0.63)∗
(0.66)#
21(1.00)∗
(0.91)#
28(1.12)∗
(1.16)#
18(0.85)∗
(0.78)#
20(0.80)∗
(0.83)#
25(1.13)∗
(1.19)#
23(1.09)∗
(1.00)#
17(0.68)∗
(0.70)#
23(1.04)∗
(1.09)#
16(0.76)∗
(0.69)#
15(0.60)∗
(0.62)#
4g
4j
17(0.77)∗
(0.80)#
20(0.95)∗
(0.86)#
21(0.84)∗
(0.87)#
16(0.47)∗ 13(0.44)∗ 14(0.40)∗
17(0.77)∗
(0.80)#
14(0.66)∗
(0.60)#
16(0.64)∗
(0.66)#
(0.51)#
34
31
(0.50)#
29
26
(0.48)#
35
29
Std.1
Std. 2
22
21
21
23
25
24
aAverage zone of inhibition in mm.
bConcentration of test compounds and standard 100 µg/mL.
Activity index = Inhibition zone of the sample / Inhibition zone of the standard.
∗Activity index against std. 1.
#Activity index against std. 2.
For antibacterial activity: Std. 1 = ciprofloxacin and Std. 2 = sulphacetamide; for antifungal
activity: Std. 1 = gentamicin and Std. 2 = clotrimazole.
Elmer RMU 6D mass spectrophotometer. Elemental analysis was determined
by the FLASH EA 1112 CHN analyzer, Thermo Finigin, Italy.
2-Amino-4-(4ꢀ-hydroxyphenyl) thiazole (1a)
A mixture of p-hydroxyacetophenone (0.1 mol), thiourea (0.2 mol), and io-
dine (0.2 mol) was heated in a water bath for 18 h with occasional stirring
and then cooled. The residue was titrated with ether to remove excess of un-
reacted p-hydroxyacetophenone. It was then washed with sodium thiosulfate

V.S. Taile et al.
212
to removed iodine impurity. The crude product was dissolved in boiling water
and filtered hot. The titled compound was formed after neutralized with aque-
ous ammonia; the white-colored compound was formed and crystallized from
ethanol to get pale yellow needles. Yield 57%; mp 201◦C; The infrared spectrum
of the compound showed 3487.8 ( OH), 3379.5 ( NH2), 3127.7 (Ar H), 1600
(C C), 1273 (C N). 1H NMR: δ 6.4 (s, 1H, thiazole), 6.8–7.8 (m, 4H, Ar H), 4.8
(bs, 2H, NH2), 5.6 (s, 1H, OH). Anal. Calcd for C9H8N2OS (192.24): C, 56.23;
H, 4.19; N, 14.97; S, 16.68. Found: C, 56.24; H, 4.17; N, 14.97; S, 16.69.
General procedure for the preparation of 2-(Substituted
benzylideneamino)-4-(4ꢀ-hydroxyphenyl) thiazoles (2a–j)
A suspension of 2-amino-4-(4ꢁ-hydroxyphenyl) thiazole (0.02 mol) and aro-
matic and heterocyclic aldehyde (0.02 mol) in alcohol was taken in a 250-mL
round-bottom flask. To this mixture a few drops of conc. H2SO4 were added.
The mixture was refluxed for about half an hour. It was cooled and poured in
ice-cold water, filtered, and dried. It was crystallized from ethanol.
2-(Benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2a)
Yield 54%; mp 168◦C (ethanol); FT-IR: 3519 ( OH), 3038.0 (aromatic ring,
str.), 1610 (C N) linkage, 1330 (SO2, asymmetric stretching), 1170.4 (SO2,
symmetric stretching, 1069.3 (C N,). 1H NMR: δ 6.6–7.6 (m, 9H, Ar H), 5.3 (s,
1H, OH), 7.8 (s, 1H, thiazole), 8.1 (s, 1H, CH N). Anal. Calcd for C16H12N2OS
(280.34): C, 68.55; H, 4.31; N, 9.99; S, 11.44. Found: C, 68.58; H, 4.31; N, 10.02;
S, 11.43.
2-(4-Chlorobenzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2b)
Yield 77%; mp 155◦C (ethanol); FT-IR: 3438 ( OH), 3088.0 (aromatic
ring, str.), 1615 (C N) linkage, 1334 (SO2, asymmetric stretching), 1166.2
(SO2, symmetric stretching, 1070.2 (C N). 1H NMR: δ 6.2–7.4 (m, 8H, Ar H),
5.2 (s, 1H, OH), 7.5 (s, 1H, thiazole), 8.5 (s, 1H, CH N). Anal. Calcd for
C16H11ClN2OS (314.79): C, 61.05; H, 3.52; Cl, 11.26; N, 8.90; S, 10.19. Found:
C, 61.08; H, 3.51; Cl, 11.29; N, 8.92; S, 10.19.
2-(4-Methoxybenzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2c)
Yield 69%; mp 160◦C (ethanol); FT-IR: 3518 ( OH), 3175.0 (aromatic ring,
str.), 1626 (C N) linkage, 1330 (SO2, asymmetric stretching), 1170.3 (SO2,
symmetric stretching), 1073.0 (C N). 1H NMR: δ 3.76 (s, 3H, OCH3), 5.4 (s, 1H,
OH), 6.4–7.3 (m, 8H, Ar H), 7.6 (s, 1H, thiazole), 8.2 (s,1H, CH N). Anal.
Calcd for C17H14N2O2S (310.37): C, 65.79; H, 4.55; N, 9.03; S, 10.33. Found: C,
65.77; H, 4.55; N, 9.01; S, 10.29.

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
213
2-(3-Nitrobenzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2d)
Yield 65%; mp 120◦C (ethanol); FT-IR: 3385 ( OH), 2995.5 (aromatic
ring, str.), 1610 (C N) linkage, 1335 (SO2, asymmetric stretching), 1164.0
(SO2, symmetric stretching, 1066.5 (C N). 1H NMR: δ 6.4–7.3 (m, 8H, Ar H),
5.3 (s, 1H, OH), 7.9 (s, 1H, thiazole), 8.8 (s, 1H, CH N). Anal. Calcd for
C16H11ClN2OS (325.34): C, 59.07; H, 3.41; N, 12.92; S, 9.86. Found: C, 59.06;
H, 3.45; N, 12.90; S, 9.89.
2-(4-Fluorobenzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2e)
Yield 62%; mp 161◦C (ethanol); FT-IR: 3415 ( OH), 3015.5 (aromatic
ring, str.), 1624 (C N) linkage, 1352 (SO2, asymmetric stretching), 1158.0
(SO2, symmetric stretching, 1082.0 (C N). 1H NMR: δ 6.2–7.5 (m, 8H, Ar H),
5.7 (s, 1H, OH), 8.2 (s, 1H, thiazole), 8.9 (s, 1H, CH N). Anal. Calcd for
C16H11FN2OS (298.33): C, 64.41; H, 3.72; F, 6.37; N, 9.39; S, 10.75. Found:
C, 64.42; H, 3.75; F, 6.35; N, 9.41; S, 10.78.
2-(3-Indolylmethylenamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2f)
Yield 75%; mp 190◦C (ethanol); FT-IR: 3440 ( OH), 3008.2 (aromatic ring,
str.), 1638 (C N) linkage, 1348 (SO2, asymmetric stretching), 1155.2 (SO2,
symmetric stretching), 1089.2 (C N). 1H NMR: δ 6.8–7.9 (m, 8H, Ar H), 5.2
(s, 1H, OH), 8.1 (s, 1H, thiazole), 8.5 (s, 1H, CH N); 9.7 (s, 1H, NH). Anal.
Calcd for C18H13N3OS (319.38): C, 67.69; H, 4.10; N, 13.16; S, 10.04. Found: C,
67.69; H, 4.12; N, 13.17; S, 10.07.
2-(2-Pyridinylmethyleneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2g)
Yield 73%; mp 180◦C (ethanol); FT-IR: 3385 ( OH), 3080.2 (aromatic ring,
str.), 1634 (C N) linkage, 1326 (SO2, asymmetric stretching), 1172.0 (SO2,
symmetric stretching), 1080.5 (C N). 1H NMR: δ 5.2 (s, 1H, OH), δ 7.0–7.9
(m, 8H, Ar H), 8.2 (s, 1H, thiazole), 8.5 (s, 1H, CH N). Anal. Calcd for
C15H11N3OS (281.33): C, 64.04; H, 3.94; N, 14.94; S, 11.40. Found: C, 64.07;
H, 3.96; N, 14.94; S, 11.39.
2-(3-Pyridinylmethyleneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2h)
Yield 68%; mp 174◦C (ethanol); FT-IR: 3408 ( OH), 3118.4 (aromatic ring,
str.), 1645 (C N) linkage, 1328 (SO2, asymmetric stretching), 1166.0 (SO2,
symmetric stretching), 1076.1 (C N). 1H NMR: δ 5.4 (s, 1H, OH), δ 6.4–7.6
(m, 8H, Ar H), 7.9 (s, 1H, thiazole), 8.4 (s, 1H, CH N). Anal. Calcd for
C15H11N3OS (281.33): C, 64.04; H, 3.94; N, 14.94; S, 11.40. Found: C, 64.10;
H, 3.92; N, 14.93; S, 11.41.

V.S. Taile et al.
214
2-(4-Pyridinylmethyleneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2i)
Yield 78%; mp 192◦C (ethanol); FT-IR: 3467.8 ( OH), 3088.5 (aromatic
ring, str.), 1650 (C N) linkage, 1325 (SO2, asymmetric stretching), 1158.0
(SO2, symmetric stretching), 1079.7 (C N). 1H NMR: δ 5.6 (s, 1H, OH), δ
6.3–7.7 (m, 8H, Ar H), 7.6 (s, 1H, thiazole), 8.0 (s, 1H, CH N). Anal. Calcd
for C15H11N3OS (281.33): C, 64.04; H, 3.94; N, 14.94; S, 11.40. Found: C, 64.00;
H, 3.96; N, 13.98; S, 11.42.
2-(2-Furylmethyleneamino)-4-(4ꢁ-hydroxyphenyl) thiazole (2j)
Yield 62%; mp 185◦C (ethanol); FT-IR: 3515.4 ( OH), 3108.5 (aromatic
ring, str.), 1646 (C N) linkage, 1338 (SO2, asymmetric stretching), 1152.2
(SO2, symmetric stretching), 1089.0 (C N). 1H NMR: δ 5.1 (s, 1H, OH), δ
6.2–7.3 (m, 3H, furan), 7.3–8.5 (m, 4H, Ar H), 8.8 (s, 1H, thiazole), 9.2 (s, 1H,
CH N). Anal. Calcd for C14H10N2O2S (270.31): C, 62.21; H, 3.73; N, 10.36;
S, 11.86. Found: C, 62.20; H, 3.75; N, 10.35; S, 11.85.
General procedure for the preparation of 2-(substituted
benzylideneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢀ-O-β-
D-glucosidoxyphenyl) thiazoles (3a–j)
A solution of 3 g potassium salt of 2-(substituted benzylideneamino)-4-(4ꢁ-
hydroxyphenyl) thiazoles in 10 mL of 5% methanolic KOH was added dropwise
to a solution of 5 g of acetobromoglucose in 20 mL of dry acetone. The resulting
mixture was stirred at 0◦C for 2 h. The reaction was allowed to proceed for an
additional 24 h and the solvent removed under reduced pressure. The reaction
was monitored by TLC. A brown syrupy mass of 3a–j was obtained.
2-(Benzylideneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-glucosidoxyphenyl)
thiazole (3a)
30
Yield 63%; [α]D = –11.10 (c, 0.1, DMSO); brown syrup; FT-IR: 1556.4
1
(C N), 1077.4 (C O C), 625.4 (C S, bend); H NMR: 2.01, 2.05, 1.99, 2.00
(s, 3H) (COCH3), 5.4 (d, 1H, anomeric proton), 6.5–7.9 (m, 9H, Ar H), 7.5 (s,
1H, thiazole), 7.9 (s, 1H, CH N). Anal. Calcd for C30H30N2O10S (610.63): C,
59.01; H, 4.95; N, 4.59; S, 5.25. Found: C, 59.02; H, 4.96; N, 4.60; S, 5.25.
2-(4-Chlorobenzylideneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3b)
30
Yield 69%; [α]D = –14.12 (c, 0.1, DMSO); brown syrup; FT-IR: 1563.2
1
(C N), 1082.0 (C O C), 628.2 (C S, bend); H NMR: 2.00, 2.02, 1.99, 1.98
(s, 3H) (COCH3), 5.8 (d, 1H, anomeric proton), 6.2–7.8 (m, 8H, Ar H), 7.6 (s,
1H, thiazole), 7.8 (s, 1H, CH N). Anal. Calcd for C30H29ClN2O10S (645.08):

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
215
C, 55.86; H, 4.53; Cl, 5.50; N, 4.34; S, 4.97. Found: C, 55.90; H, 4.54; Cl, 5.52;
N, 4.36; S, 4.99.
2-(4-Methoxybenzylideneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3c)
30
Yield 65%; [α]D = +15.23 (c, 0.1, DMSO); brown syrup; FT-IR: 1551.0
1
(C N), 1081.2 (C O C), 630.1 (C S, bend); H NMR: 2.02, 2.01, 2.00, 1.97
(s, 3H) (COCH3), δ 3.92 (s, 3H, OCH3), 5.9 (d, 1H, anomeric proton), 6.2–7.6
(m, 8H, Ar H), 7.8 (s, 1H, thiazole), 8.4 (s, 1H, CH N). Anal. Calcd for
C31H32N2O11S (640.66): C, 58.12; H, 5.03; N, 4.37; S, 5.01. Found: C, 58.12;
H, 5.04; N, 4.38; S, 5.05.
2-(3-Nitrobenzylideneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3d)
30
Yield 64%; [α]D = –15.25 (c, 0.1, DMSO); brown syrup; FT-IR: 1562.2
1
(C N), 1080.5 (C O C), 624.8 (C S, bend); H NMR: 2.01, 2.00, 2.01, 1.99
(s, 3H) (COCH3), 5.7 (d, 1H, anomeric proton), 6.1–7.4 (m, 8H, Ar H), 7.5 (s,
1H, thiazole), 8.2 (s, 1H, CH N). Anal. Calcd for C30H29N2O12S (655.63): C,
54.96; H, 4.46; N, 6.41; S, 4.89. Found: C, 54.95; H, 4.44; N, 6.39; S, 4.91.
2-(4-Fluorobenzylideneamino)-4–4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3e)
30
Yield 59%; [α]D = –10.12 (c, 0.1, DMSO); brown syrup; FT-IR: 1546.1
1
(C N), 1084.0 (C O C), 629.2 (C S, bend); H NMR: 2.00, 2.01, 2.03, 1.96
(s, 3H) (COCH3), 5.9 (d, 1H, anomeric proton), 6.3–7.4 (m, 8H, Ar H), 7.7 (s,
1H, thiazole), 8.4 (s, 1H, CH N). Anal. Calcd for C30H29FN2O10S (628.62):
C, 57.32; H, 4.65; F, 3.02; N, 4.46; S, 5.10. Found: C, 57.35; H, 4.66; F, 3.00; N,
4.50; S, 5.10.
2-(3-Indolylmethylenamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3f)
30
Yield 68%; [α]D = +19.18 (c, 0.1, DMSO); brown syrup; FT-IR: 1645.0
1
(C N), 1075.5 (C O C), 625.5 (C S, bend); H NMR: 1.99, 2.00, 2.01, 2.00
(s, 3H) (COCH3), 6.1 (d, 1H, anomeric proton), 6.4–7.7 (m, 8H, Ar H), 7.9
(s, 1H, thiazole), 8.5 (s, 1H, CH N), 10.3 (s, 1H, NH). Anal. Calcd for
C31H32N3O10S (649.67): C, 59.16; H, 4.81; N, 6.47; S, 4.94. Found: C, 59.15;
H, 4.80; N, 6.48; S, 4.92.
2-(2-Pyridinylmethyleneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3g)
30
Yield 73%; [α]D = –17.45 (c, 0.1, DMSO); brown syrup; FT-IR: 1668.4
1
(C N), 1086.2 (C O C), 630.2 (C S, bend); H NMR: 2.00, 2.01, 1.99, 2.00
(s, 3H) (COCH3), 5.8 (d, 1H, anomeric proton), 6.1–7.5 (m, 8H, Ar H), 7.9 (s,

V.S. Taile et al.
216
1H, thiazole), 8.4 (s, 1H, CH N). Anal. Calcd for C29H29N3O10S (611.62): C,
56.95; H, 4.78; N, 6.87; S, 5.24. Found: C, 56.98; H, 4.80; N, 6.85; S, 5.25.
2-(3-Pyridinylmethyleneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3h)
30
Yield 61%; [α]D = –12.34 (c, 0.1, DMSO); brown syrup; FT-IR: 1680.0
1
(C N), 1090.4 (C O C), 635.0 (C S, bend); H NMR: 1.99, 2.01, 2.00, 2.02
(s, 3H) (COCH3), 5.6 (d, 1H, anomeric proton), 6.0–7.6 (m, 8H, Ar H), 8.5 (s,
1H, thiazole), 8.8 (s, 1H, CH N). Anal. Calcd for C29H29N3O10S (611.62): C,
56.95; H, 4.78; N, 6.87; S, 5.24. Found: C, 56.94; H, 4.77; N, 6.88; S, 5.27.
2-(4-Pyridinylmethyleneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3i)
30
Yield 59%; [α]D = –8.26 (c, 0.1, DMSO); brown syrup; FT-IR: 1677.2
1
(C N), 1082.0 (C O C), 638.0 (C S, bend); H NMR: 2.00, 2.01, 1.99, 2.03
(s, 3H) (COCH3), 6.1 (d, 1H, anomeric proton), 6.4–7.7 (m, 8H, Ar H), 8.0 (s,
1H, thiazole), 8.4 (s, 1H, CH N). Anal. Calcd for C29H29N3O10S (611.62): C,
56.95; H, 4.78; N, 6.87; S, 5.24. Found: C, 56.92; H, 4.76; N, 6.87; S, 5.26.
2-(2-Furylmethyleneamino)-4-(2, 3, 4, 6-tetera-O-acetyl-4ꢁ-O-β-D-
glucosidoxyphenyl) thiazole (3j)
30
Yield 62%; [α]D = +12.11 (c, 0.1, DMSO); brown syrup; FT-IR: 1680.2
1
(C N), 1089.5 (C O C), 632.0 (C S, bend); H NMR: 1.99, 2.01, 2.04, 2.00
(s, 3H) (COCH3), 6.0 (d, 1H, anomeric proton), 6.2–7.5 (m, 7H, Ar H), 8.4 (s,
1H, thiazole), 8.8 (s, 1H, CH N). Anal. Calcd for C28H28N2O12S (616.59): C,
55.96; H, 4.70; N, 4.66; S, 5.34. Found: C, 55.95; H, 4.71; N, 4.70; S, 5.35.
General procedure for the preparation of 2-(substituted
benzylideneamino)-4-(4ꢀ-O-β-D-glucosidoxyphenyl) thiazoles
(4a–j)
To a solution of 2-(substituted benzylideneamino)-4-(2,3,4,6-tetera-O-
acetyl-4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (2 g) in 25 mL of dry methanol
was added 1.5 mL of 5% CH3ONa solution. The reaction mixture was kept at
rt for an additional 24 h. It was neutralized with ion-exchange resin (Amberlite
IR 120, s.d. fine, H+ form), filtered, and concentrated in vacuo to afford viscous,
strongly hygroscopic brown-colored syrupy.
2-(Benzylideneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4a)
30
Yield 71%; [α]D = –7.25 (c, 0.1, DMSO); brown syrup; FT-IR: 3365.7
( OH, broad, stretching), 2158.91 (aromatic str.), 1566 (C N), 1075.9
1
(C O C), 625.4 (C S, bend). H NMR: 3.4 (1H, 5ꢁH), 3.5 (1H, 4ꢁH), 3.8 (1H,
3ꢁH), 4.0 (1H, 2ꢁH), 5.9 (dd, 1H, J1, 2 = 8.6 Hz, 1ꢁH, anomeric proton), 6.2–7.9

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
217
(m, 9H, Ar H), 8.5 (s, 1H, thiazole), 9.1 (s, 1H, CH N). 13C NMR: δ 175,
165.0, 158.2, 152.4, 140.8, 139.4, 130.8, 130.2, 129.0, 128.8, 128.4, 128.0, 125.6,
120.0, 110.0, 106.2, 99.5, 82.4, 78.2, 75.8, 73.1, 72.5, 65.2. EI-MS: 442.6 (M)
(28%), 285 (20%), 190 (100%) base peak, 163 (10%), 117 (14%), 90 (8%), 71
(9%). Anal. Calcd for C22H21ClN2O6S (442.48): C, 59.72; H, 5.01; N, 6.33; S,
7.25. Found: C, 59.75; H, 5.02; N, 6.32; S, 7.24.
2-(4-Chlorobenzylideneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4b)
30
Yield 71%; [α]D = –13.25 (c, 0.1, DMSO); brown syrup; FT-IR: 3418.2
( OH, broad, stretching) 2455.6 (aromatic str.), 1560 (C N), 1081.2 (C O C),
630.4 (C S, bend). 1H NMR: 3.0 (1H, 5ꢁH), 3.2 (1H, 4ꢁH), 3.5 (1H, 3ꢁH), 3.8 (1H,
2ꢁH), 6.0 (dd, 1H, J1, 2 = 8.8 Hz, 1ꢁH, anomeric proton), 6.3–7.8 (m, 8H, Ar H),
7.9 (s, 1H, thiazole), 9.4 (s, 1H, CH N). 13C NMR: δ 173, 168.2, 157.2, 153,6,
141.8, 139.0, 131.2, 130.4, 130.2, 129.7, 128.0, 127.0, 126.3, 121.1, 111.4, 105.6,
99.4, 82.6, 77.2, 76.8, 75.6, 73.6, 65.0. EI-MS: 476.6 (M) (12%), 315 (100%) base
peak, 203 (14%), 165 (18%), 118 (24%), 94 (14%), 77 (21%). Anal. Calcd for
C22H22N2O6S (476.93): C, 55.40; H, 4.44; Cl, 7.43; N, 5.87; S, 6.72. Found: C,
55.41; H, 4.43; Cl, 7.43; N, 5.90; S, 6.72.
2-(4-Methoxybenzylideneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4c)
30
Yield 50%; [α]D
= +15.10 (c, 0.1, DMSO); brown syrup; FT-IR:
3388.8 ( OH, broad, stretching), 2542.2 (aromatic str.), 1565 (C N), 1080.5
(C O C), 632.5 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.2 (1H, 4ꢁH), 3.3 (1H,
1
3ꢁH), 3.9 (1H, 2ꢁH), 4.02 (s, 3H, OCH3), 6.1 (dd, 1H, J1, 2 = 8.0 Hz, 1ꢁH, anomeric
proton) 6.3–7.8 (m, 8H, Ar H), 8.0 (s, 1H, thiazole), 8.8 (s, 1H, CH N). 13
C
NMR: δ 173.2, 164.2, 160.1, 157.1, 152.3, 135.2, 134.2, 133.2, 129.0, 128.2,
127.4, 127.0, 126.6, 125.0, 112.2, 105.0, 88.6, 78.2, 76.4, 75.2, 74.3, 65.5, 55.6.
EI-MS: 473.0 (M) (22%), 280 (20%), 188 (100%) base peak, 165 (18%), 130
(32%), 94 (13%), 78 (16%). Anal. Calcd for C23H24N2O7S (472.51): C, 58.46;
H, 5.12; N, 5.93; S, 6.79. Found: C, 58.46; H, 5.14; N, 5.93; S, 6.80.
2-(3-Nitrobenzylideneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4d)
30
Yield 70%; [α]D
= −11.35 (c, 0.1, DMSO); brown syrup; FT-IR:
3456.2 ( OH, broad, stretching), 2352.0 (aromatic str.), 1560 (C N), 1084.4
(C O C), 628.4 (C S, bend). H NMR: 3.0 (1H, 5ꢁH), 3.2 (1H, 4ꢁH), 3.6 (1H,
1
3ꢁH), 3.8 (1H, 2ꢁH), 5.8 (dd, 1H, J1, 2 = 8.2 Hz, 1ꢁH, anomeric proton) 6.0–7.6 (m,
8H, Ar H), 7.9 (s, 1H, thiazole), 8.2 (s, 1H, CH N). 13C NMR: δ 174.0, 165.3,
162.5, 158.0, 155.4, 135.5, 134.2, 134.6, 130.3, 129.2, 128.5, 127.0, 126.0, 125.6,
122.6, 105.2, 92.6, 80.2, 76.4, 75.1, 74.2, 66.5, 65.2. EI-MS: 488.20 (M) (24%),
190 (21%), 164 (12%), 151 (100%) base peak, 135 (18%), 92 (9%), 77 (26%). Anal.
Calcd for C22H21N3O8S (487.48): C, 54.20; H, 4.34; N, 8.62; S, 6.58. Found: C,
54.21; H, 4.34; N, 8.63; S, 6.56.

V.S. Taile et al.
218
2-(4-Fluorobenzylideneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4e).
30
Yield 62%; [α]D
= −9.10 (c, 0.1, DMSO); brown syrup; FT-IR:
3510.3 ( OH, broad, stretching), 2456.4 (aromatic str.), 1566 (C N), 1089.6
(C O C), 632.0 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.4 (1H, 4ꢁH), 3.5 (1H,
1
3ꢁH), 3.7 (1H, 2ꢁH), 6.1 (dd, 1H, J1, 2 = 8.4 Hz, 1ꢁH, anomeric proton) 6.3–7.9
(m, 8H, Ar H), 8.3 (s, 1H, thiazole), 8.7 (s, 1H, CH N). 13C NMR: δ 176.2,
164.2, 163.2, 160.0, 157.0, 136.4, 135.3, 134.0, 132.8, 130.2, 129.5, 128.0, 127.4,
126.4, 120.2, 105.8, 95.6, 81.2, 76.5, 75.0, 74.6, 65.0, 62.4. EI-MS: 461.14 (M)
(26%), 298 (28%), 214 (11%), 190 (100%) base peak, 165 (12%), 150 (19%), 136
(35%), 77 (36%). Anal. Calcd for C22H21FN2O6S (460.48): C, 57.38; H, 4.60; F,
4.13; N, 6.08; S, 6.96. Found: C, 57.41; H, 4.61; F, 4.13; N, 6.09; S, 6.95.
2-(3-Indolylmethylenamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4f)
30
Yield 59%; [α]D
= −18.18 (c, 0.1, DMSO); brown syrup; FT-IR:
3442.2 ( OH, broad, stretching), 2515.2 (aromatic str.), 1556 (C N), 1092.5
(C O C), 630.2 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.2 (1H, 4ꢁH), 3.4 (1H,
1
3ꢁH), 3.8 (1H, 2ꢁH), 5.8 (dd, 1H, J1, 2 = 8.6 Hz, 1ꢁH, anomeric proton) 6.2–7.8
(m, 8H, Ar H), 8.1 (s, 1H, thiazole), 8.6 (s, 1H, CH N), 9.8 (s, 1H, NH).
13C NMR: δ 174.0, 172.0, 160.2, 157.4, 154.6, 136.3, 135.7, 134.5, 133.8, 130.1,
129.0, 128.2, 128.8, 127.5, 115.2, 114.7, 110.4, 105.2, 103.4, 95.7, 80.2, 75.1,
74.2, 65.6. EI-MS: 483.20 (M) (11%), 318 (31%), 310 (9%), 188 (100%) base
peak, 163 (23%), 131 (25%), 118 (12%), 77 (21%). Anal. Calcd for C24H23N3O6S
(481.52): C, 59.86; H, 4.81; N, 8.73; S, 6.66. Found: C, 59.88; H, 4.80; N, 8.74; S,
6.65.
2-(2-Pyridinylmethyleneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4g)
30
Yield 68%; [α]D = −17.02 (c, 0.1, DMSO); brown syrup; FT-IR: 3312.0
( OH, broad, stretching), 2310.5 (aromatic str.), 1568.8 (C N), 1085.2
1
(C O C), 629.6 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.6 (1H, 4ꢁH), 3.8 (1H,
3ꢁH), 3.9 (1H, 2ꢁH), 6.1 (dd, 1H, J1, 2 = 8.6 Hz, 1ꢁH, anomeric proton) 6.3–7.9
(m, 8H, Ar H), 8.4 (s, 1H, thiazole), 8.8 (s, 1H, CH N), 13C NMR: δ 173.8,
165.4, 160.4, 157.2, 154.8, 149.8, 135.6, 134.0, 133.4, 132.2, 130.0, 129.2, 128.5,
127.3, 118.2, 115.4, 110.2, 106.1, 94.7, 82.4, 75.6, 74.6, 65.1. EI-MS: 444.12 (M)
(24%), 311 (28%), 280 (100%) base peak, 201 (34%), 164 (16), 111 (15%), 78
(9%). Anal. Calcd for C21H21N3O6S (443.47): C, 56.87; H, 4.77; N, 9.48; S, 7.23.
Found: C, 56.89; H, 4.78; N, 9.50; S, 7.24.
2-(3-Pyridinylmethyleneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4h)
30
Yield 63%; [α]D = −11.28 (c, 0.1, DMSO); brown syrup; FT-IR: 3410.2
( OH, broad, stretching), 2414.2 (aromatic str.), 1570.5 (C N), 1088.3
1
(C O C), 626.8 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.4 (1H, 4ꢁH), 3.5 (1H,
3ꢁH), 3.6 (1H, 2ꢁH), 5.7 (dd, 1H, J1, 2 = 8.5 Hz, 1ꢁH, anomeric proton) 6.2–7.5
(m, 8H, Ar H), 7.9 (s, 1H, thiazole), 8.2 (s, 1H, CH N), 13C NMR: δ 173.3,
166.4, 162.1, 158.8, 157.2, 150.6, 135.7, 134.8, 133.7, 132.0, 131.4, 130.2, 129.2,

Synthesis of 2-(Substituted benzylideneamino)-4-(4ꢁ-hydroxyphenyl) thiazoles
219
128.0, 127.2, 120.4, 110.2, 105.6, 95.6, 84.2, 75.2, 74.6, 65.5. EI-MS: 445.10 (M)
(34%), 314 (26%), 282 (100%) base peak, 198 (25%), 163 (12%), 110 (10%), 77
(13%). Anal. Calcd for C21H21N3O6S (443.47): C, 56.87; H, 4.77; N, 9.48; S, 7.23.
Found: C, 56.88; H, 4.77; N, 9.49; S, 7.20.
2-(4-Pyridinylmethyleneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4i)
30
Yield 57%; [α]D = −7.20 (c, 0.1, DMSO); brown syrup; FT-IR: 3318.5
( OH, broad, stretching), 2515.4 (aromatic str.), 1572.6 (C N), 1064.4
1
(C O C), 630.2 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.2 (1H, 4ꢁH), 3.5 (1H,
3ꢁH), 3.8 (1H, 2ꢁH), 6.2 (dd, 1H, J1, 2 = 8.8 Hz, 1ꢁH, anomeric proton) 6.3–7.9
(m, 8H, Ar H), 8.1 (s, 1H, thiazole), 8.7 (s, 1H, CH N), 13C NMR: δ 173.7,
169.1, 164.2, 160.6, 158.0, 151.2, 145.0, 134.0, 133.2, 132.0, 131.2, 130.2, 129.2,
128.4, 125.2, 121.4, 110.5, 105.0, 96.2, 84.1, 75.0, 74.2, 65.2. EI-MS: 446.10 (M)
(41%), 311 (22%), 281 (100%) base peak, 200 (25%), 165 (15%), 112 (12%), 79
(14%). Anal. Calcd for C21H21N3O6S (443.47): C, 56.87; H, 4.77; N, 9.48; S, 7.23.
Found: C, 56.87; H, 4.75; N, 9.44; S, 7.21.
2-(2-Furylmethyleneamino)-4-(4ꢁ-O-β-D-glucosidoxyphenyl) thiazoles (4j)
30
Yield 60%; [α]D = +6.45 (c, 0.1, DMSO); brown syrup; FT-IR: 3404.5
( OH, broad, stretching), 2610.2 (aromatic str.), 1575.2 (C N), 1080.2
1
(C O C), 625.5 (C S, bend). H NMR: 3.1 (1H, 5ꢁH), 3.4 (1H, 4ꢁH), 3.5 (1H,
3ꢁH), 3.9 (1H, 2ꢁH), 5.9 (dd, 1H, J1, 2 = 8.4 Hz, 1ꢁH, anomeric proton) 6.1–7.8
(m, 8H, Ar H), 8.6 (s, 1H, thiazole), 8.9 (s, 1H, CH N). 13C NMR: δ 173.0,
166.2, 153.1, 151.0, 150.0, 146.4, 145.2, 135.6, 130.2, 129.2, 128.4, 127.2, 110.5,
109.0, 105.1, 95.1, 85.2, 75.4, 73.1, 65.8. EI-MS: 435.10 (M) (8%), 325 (25%),
270 (100%) base peak, 190 (12%), 164 (18%), 92 (30%), 77 (17%). Anal. Calcd
for C20H20N2O7S (432.45): C, 55.55; H, 4.66; N, 6.48; S, 7.41. Found: C, 55.56;
H, 4.65; N, 6.48; S, 7.42.
ACKNOWLEDGEMENT
The authors are thankful to the director of the Sophisticated Analytical Instru-
ment Facility (SAIF), Chandigarh, IIT-Powai Mumbai, for providing necessary
spectral analysis; the head of the Department of Chemistry for providing nec-
essary laboratory facilities; and the dead of the Department of Pharmacy for
the biological activities.
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