Synthesis and antimicrobial evaluation of some new thiazolo imidazole analogs

Article abstract of DOI:10.14233/ajchem.2017.20738

Thiazole and imidazole derivatives have attracted medicinal chemists owing to their extensive biological activities. Present paper describes the synthesis of some new thiazolo imidazole derivatives. 4-Substituted phenacyl bromides were prepared from subst

Full text of DOI:10.14233/ajchem.2017.20738

Asian Journal of Chemistry; Vol. 29, No. 12 (2017), 2639-2642
A
SIAN
J
OURNAL OF HEMISTRY
C
https://doi.org/10.14233/ajchem.2017.20738
Synthesis and Antimicrobial Evaluation of Some New Thiazolo Imidazole Analogs
2
S. RAMAMURTHY1,* and E. JAYACHANDRAN
1Department of Pharmaceutical Chemistry, Visveswarapura Institute of Pharmaceutical Sciences, B.S.K II Stage, Bangalore-560 070, India
2S.C.S. College of Pharmacy, Harapanahalli-583 131, India
*Corresponding author: E-mail: ramamurthyronisha@yahoo.com; ramamurthyvips@gmail.com
Received: 27 April 2017;
Accepted: 31 May 2017;
Published online: 30 October 2017;
AJC-18606
Thiazole and imidazole derivatives have attracted medicinal chemists owing to their extensive biological activities. Present paper describes
the synthesis of some new thiazolo imidazole derivatives. 4-Substituted phenacyl bromides were prepared from substituted acetophenones.
The products were condensed with thiourea to obtain 2-amino-4-(4-substituted phenyl)thiazoles which on further reaction with 4-substituted
phenacyl bromides resulted in 3,6-di(substituted phenyl)imidazo[2,1-b] thiazoles (3a-3i). The formation of all the compounds was established
by spectral techniques like IR, 1H NMR and Mass spectral data. The title compounds were screened for their antimicrobial activity against
Gram-positive bacteria S. aureus and B. subtilis, Gram-negative bacteria E. coli and K. pneumoniae and the fungal strains like A. niger,
C. albicans and C. neoformans. The results indicated that the compounds coded 3a, 3c, 3g and 3i showed significant activity than the
remaining compounds.
Keywords: Thiazole, Imidazoles, Synthesis, Antibacterial, Antifungal.
Thiazolo imidazoles are the fused ring systems involving
thiazole and imidazole with a common brige-head nitrogen at
position-4. Substituted thiazolo imidazoles are also of great
importance because of their remarkable biological activities
including antimicrobial [16], anticancerous [17], antiproli-
ferative [18], antitubercular [19], lipoxygenase inhibiting [20],
anti-infective activity [16], etc. Still their antimicrobial acti-
vities have shown only handful of results so far. In continuation
to these efforts and with an objective to develop novel and
potent therapeutic agents of synthetic origin, we have studied
and reported the synthesis, characterization and antimicrobial
activity of some novel thaizolo imidazole analogs.
INTRODUCTION
Over the past few decades considerable advances have
been achieved in the introduction of new structural prototypes
as effective antimicrobials. Many antimicrobial agents still
suffer from major limitations like lack of selectivity, their
unwanted side effects, non-economical and time-consuming
synthetic processes, emergence of drug resistance by the micro-
organisms, etc. Therefore attention is focussed in the design
and synthesis of new antimicrobial agents to overcome these
limitations.
Among the various types of heterocyclic compounds,
thiazole and imidazole derivatives have received considerable
attention towards synthetic medicinal chemists as they are
endowed with wide range of therapeutic properties and
applications. Compounds containing thiazole nucleus are
unique molecules reported to possess an array of biological
activities such as antibacterial [1], antifungal [2], antitumor
[3,4], anti-inflammatory [5,6], anticonvulsant [7], anthelmintic
activity [8], etc. Imidazoles are more vital in many biological
processes since they are present in many natural compounds.
Many synthetic pyrimidine analogs are also known to exhibit
a variety of therapeutic uses including antiviral [9], anti-
mycobacterial [10], antitumor [11], anti-inflammatory [12],
antidepressant [13], branchodilatory [14], antifungal activity
[15], etc.
EXPERIMENTAL
All the chemicals and solvents were of analytical grade
and procured from commercial suppliers and used without
purification or drying unless otherwise noted. The melting
points of the intermediates and products were determined in
open capillary tubes and uncorrected. The purity of the
compounds was routinely checked by TLC using silica gel-G
with solvents as n-hexane and ethyl acetate (7:3). The physical
data of the compounds is shown separately (Table-1). UV- absor-
ption data of the intermediates and target compounds was colle-
cted by using UV-visible spectrophotometer SL-159, Elico
India Ltd. reported in λmax values. 1H NMR spectra were recorded
in DMSO at 400 MHz on BrukerAMX using tetramethylsilane

2640 Ramamurthy et al.
Asian J. Chem.
TABLE-1
PHYSICAL DATA OF THE TITLE COMPOUNDS
and treated with the substituted 2-phenacyl bromide (0.01 mol).
The mixture was refluxed for 8 h and then concentrated to 10
mL. To make the resulting solution alkaline, 15 % NH4OH was
added drop-wise to get pH 8-9. The mixture was then poured
into CH2Cl2, washed and concentrated [17,23]. The product
was filtered and recrystallized from absolute alcohol (Scheme-I).
The spectral data of the products (3a-3i) is given below:
3,6-Di(4-chloro phenyl)imidazo[2,1-b]thiazole (3a):
λmax 265 nm, IR (KBr, νmax, cm-1): 3056.50 (Ar-CH, str.),
2912.80 (Aliph.CH, str), 1687.20 (Ar C=C-), 1537.15 (C=N
str), 762.33 (C-S), 692.05 (C-Cl); 1H NMR (DMSO) δ ppm:
8.52 (s, 1H, imid N-H), 7.92 (d, 2H, 22 & 62-H, phenyl ring
on imid), 7.50 (d, 2H, 22 & 62-H, phenyl ring on thiaz.), 7.30
(d, 2H, 32 & 52-H, phenyl ring on thiaz.), 6.92 (d, 2H, 32 &
52-H, phenyl ring on imid.), 6.46 (s, 22-H, thiaz.); MS: m/z:
344.12 [M]+.
3-(4-Chloro phenyl)-6-(4-methoxy phenyl)imidazo[2,1-
b]thiazole (3b): λmax 268 nm; IR (KBr, νmax, cm-1): 3052.30
(Ar-CH, str.), 2910.80 (Aliph.CH, str), 1686.10 (Ar C=C-),
1537.25 (C=N str), 1245.45 (Ar-O-C, str), 762.33 (C-S),
692.05 (C-Cl); 1H NMR (DMSO) δ ppm: 8.54 (s, 1H, imid N-
H), 7.95 (d, 2H, 22 & 62-H, phenyl ring on imid), 7.55 (d, 2H,
22 & 62-H, phenyl ring on thiaz.), 7.38 (d, 2H, 32 & 52-H,
phenyl ring on thiaz.), 6.90 (d, 2H, 32 & 52-H, phenyl ring on
imid.), 6.46 (s, 22-H, thiaz.), 3.86 (s, 3H, -OCH3); MS: m/z:
340.08 [M]+.
Yield
(%)
m.p.
(°C)
Code
m.f.
m.w.
Rf value
C17H10N2SCl2
C18H13ON2SCl
C17H10O2N3SCl
C18H13ON2SCl
C19H16O2N2S
C18H13O3N3S
C17H10O2N3SCl
C18H13O3N3S
C17H10O4N4S
344
340
355
340
336
351
355
351
366
78.2
74.5
62.2
70.5
67.4
70.5
66.6
68.8
71.6
188-190
202-204
156-158
170-172
139-141
208-210
150-152
218-220
146-148
0.58
0.76
0.52
0.61
0.48
0.72
0.69
0.55
0.66
3a
3b
3c
3d
3e
3f
3g
3h
3i
(TMS) as internal standard and the data was reported ppm. IR
spectra of the compounds were collected using KBr pellet on
Shimadzu FTIR-8700 spectrophotometer and frequencies were
recordedinwavenumbers. MassspectrawererecordedinShimadzu
LC MS-2010A at Quest ResearchTraining Institute Ltd. Bangalore,
India.
General procedure for the synthesis of 4-substituted
phenacyl bromides (1a-c): To a solution of 4-substituted
acetophenone (0.3 mol) and acetic acid (75 mL), added drop-
wise bromine (20 mL) in acetic acid (75 mL). The contents
were stirred for 1 h at 0-10 °C and further for 1 h at room tempe-
rature. Then the reaction mixture was poured into crushed ice,
the solid separated was filtered and washed with water [21,22].
The product was recrystallized from methanol. Rf was deter-
mined in a solvent mixture of n-hexane and ethyl acetate (7:3).
Compound 1a (R = Cl): Pale yellow solid; Yield 80.70
%; m.p. 89 °C; Rf 0.72.
3-(4-Chloro phenyl)-6-(4-nitro phenyl)imidazo[2,1b]-
thiazole (3c): λmax 268 nm; IR (KBr, νmax, cm-1): 3055.30 (Ar-
CH, str.), 1685.10 (Ar C=C-), 1536.15 (C=N str), 1350.40
(N-O of NO2), 1295.60 (Ar.C-N-, str), 763.22 (C-S), 690.15
1
(C-Cl); H NMR (DMSO) δ ppm: 8.55 (s, 1H, imid N-H),
Compound 1b (R = OCH3): Pale yellow solid;Yield 82.40
%; m.p. 80 °C; Rf 0.63.
Compound 1c (R = NO2): yellow solid; Yield 79.60 %;
m.p. 82 °C; Rf 0.69.
7.95 (d, 2H, 22 & 62-H, phenyl ring on imid), 7.52 (d, 2H, 22
& 62-H, phenyl ring on thiaz.), 7.40 (d, 2H, 32 & 52-H, phenyl
ring on thiaz.), 6.86 (d, 2H, 32 & 52-H, phenyl ring on imid.),
6.40 (s, 22-H, thiaz.); MS: m/z: 355.10 [M]+.
General procedure for the synthesis of 2-amino-4-(4-
substituted phenyl)thiazoles (2a-c): Substituted phenacyl
bromide (0.01 mol) and thiourea (0.76 g, 0.01 mol) were taken
in a reaction vessel and added water (10 mL). The reaction
mixture was irradiated under micro wave (40 W) for 10-15
min. The solid separated was filtered, washed with water and
recrystallized from absolute alcohol [17,23].
Compound 2a (R = Cl):White solid;Yield 78.70 %; m.p.
188 °C; Rf 0.80; λmax 238 nm; IR (KBr, νmax, cm-1): 3360.20
(1ºNH2, str.), 3063.22 (Ar-CH, str), 1686.10 (Ar C=C), 1602.45
(NH2 bend), 1534.30 (CN str.), 770.60 (C-S), 687.10 (C-Cl).
Compound 2b (R = OCH3): White solid;Yield 84.40 %;
m.p. 176 °C; Rf 0.68; λmax 244 nm; IR (KBr, νmax, cm-1): 3362.40
(1ºNH2, str.), 3068.28 (Ar-CH, str), 1684.16 (Ar C=C), 1605.15
(NH2 bend), 1535.35 (CN str.), 1245.45 (Ar-O-C, str), 773.65
(C-S).
Compound 2c (R = NO2): White solid; Yield 81.60 %;
m.p. 232 °C; Rf 0.76; λmax 242 nm; IR (KBr, νmax, cm-1): 3363.45
(1ºNH2, str.), 3065.20 (Ar-CH, str), 1684.30 (Ar C=C), 1604.25
(NH2 bend), 1535.35 (CN str.), 1350.40 (N-O of NO2), 773.65
(C-S).
General protocol for the synthesis of 3,6-di(substituted
phenyl)imidazo[2,1b]thiazoles (3a-i): 2-Amino-4-(4-substituted
phenyl)thiazole (0.01 mol) was dissolved in acetone (25 mL)
3-(4-Methoxy phenyl)-6-(4-chloro phenyl)imidazo[2,1-
b]thiazole (3d): λmax 270 nm; IR (KBr, νmax, cm-1): 3052.60
(Ar-CH, str.), 2911.80 (Aliph.CH, str), 1688.10 (Ar C=C-),
1536.20 (C=N str), 1247.30 (Ar-O-C, str), 764.50 (C-S),
692.70 (C-Cl); 1H NMR (DMSO) δ ppm: 8.58 (s, 1H, imid N-
H), 7.92 (d, 2H, 22 & 62-H, phenyl ring on imid), 7.54 (d, 2H,
22 & 62-H, phenyl ring on thiaz.), 7.40 (d, 2H, 32 & 52-H,
phenyl ring on thiaz.), 6.88 (d, 2H, 32 & 52-H, phenyl ring on
imid.), 6.43 (s, 22-H, thiaz.), 3.88 (s, 3H, -OCH3); MS: m/z:
340.14 [M]+.
3,6-Di(4-methoxy phenyl)imidazo[2,1-b]thiazole (3e):
λmax 280 nm; IR (KBr, νmax, cm-1): 3054.30 (Ar-CH, str.),
2911.80 (Aliph.CH, str), 1687.10 (Ar C=C-), 1539.45 (C=N
str), 1244.65 (Ar-O-C, str), 764.60 (C-S); 1H NMR (DMSO)
δ ppm: 8.60 (s, 1H, imid N-H), 7.85 (d, 2H, 22 & 62-H, phenyl
ring on imid), 7.52 (d, 2H, 22 & 62-H, phenyl ring on thiaz.),
7.40 (d, 2H, 32 & 52-H, phenyl ring on thiaz.), 6.80 (d, 2H,
32 & 52-H, phenyl ring on imid.), 6.40 (s, 22-H, thiaz.), 3.82
(s, 3H, -OCH3); MS: m/z: 336.05 [M]+.
3-(4-Methoxy phenyl)-6-(4-nitro phenyl)imidazo[2,1-
b]thiazole (3f): λmax 268 nm; IR (KBr, νmax, cm-1): 3052.30
(Ar-CH, str.), 2914.80 (Aliph.CH, str), 1685.80 (Ar C=C-),
1538.55 (C=N str), 1352.50 (N-O of NO2), 1288.60 (Ar.C-N-

Vol. 29, No. 12 (2017)
Synthesis and Antimicrobial Evaluation of Some New Thiazolo Imidazole Analogs 2641
, str) 1245.45 (Ar-O-C, str), 760.33 (C-S); 1H NMR (DMSO)
δ ppm: 8.58 (s, 1H, imid N-H), 7.90 (d, 2H, 22 & 62-H, phenyl
ring on imid), 7.55 (d, 2H, 22 & 62-H, phenyl ring on thiaz.),
7.42 (d, 2H, 32 & 52-H, phenyl ring on thiaz.), 6.92 (d, 2H,
32 & 52-H, phenyl ring on imid.), 6.48 (s, 22-H, thiaz.), 3.85
(s, 3H, -OCH3); MS: m/z: 351.14 [M]+.
Br2
R1
COCH3
R1
COCH2-Br
CH3COOH
R1 = Cl, OCH3, NO2
1a-c
H2N-CS-NH2
3-(4-Nitro phenyl)-6-(4-chloro phenyl)imidazo[2,1b]-
thiazole (3g): λmax 278 nm; IR (KBr, νmax, cm-1): 3056.40 (Ar-
CH, str.), 1688.10 (Ar C=C-), 1535.35 (C=N str), 1353.40
(N-O of NO2), 1294.60 (Ar.C-N-, str), 762.82 (C-S), 690.55
R1
N
1
NH2
(C-Cl); H NMR (DMSO) δ ppm: 8.53 (s, 1H, imid N-H),
S
2a-c
7.93 (d, 2H, 22 & 62-H, phenyl ring on imid), 7.54 (d, 2H, 22
& 62-H, phenyl ring on thiaz.), 7.40 (d, 2H, 32 & 52-H, phenyl
ring on thiaz.), 6.85 (d, 2H, 32 & 52-H, phenyl ring on imid.),
6.42 (s, 22-H, thiaz.); MS: m/z: 355.05 [M]+.
R2
COCH2-Br
3-(4-Nitro phenyl)-6-(4-methoxy phenyl)imidazo[2,1b]-
thiazole (3h): λmax 284 nm; IR (KBr, νmax, cm-1): 3050.50 (Ar-
CH, str.), 2916.70 (Aliph.CH, str), 1687.30 (Ar C=C-), 1540.55
(C=N str), 1353.80 (N-O of NO2), 1295.60 (Ar.C-N-, str),
1246.45 (Ar-O-C, str), 764.33 (C-S), 1H NMR (DMSO) δ ppm:
8.55 (s, 1H, imid N-H), 7.95 (d, 2H, 22 & 62-H, phenyl ring
on imid), 7.52 (d, 2H, 22 & 62-H, phenyl ring on thiaz.), 7.40
(d, 2H, 32 & 52-H, phenyl ring on thiaz.), 6.88 (d, 2H, 32 &
52-H, phenyl ring on imid.), 6.44 (s, 22-H, thiaz.), 3.85 (s,
3H, -OCH3); MS: m/z: 351.00 [M]+.
3,6-Di(4-nitro phenyl)imidazo[2,1-b]thiazole (3i): λmax
268 nm; IR (KBr, νmax, cm-1): 3052.30 (Ar-CH, str.), 1685.80
(Ar C=C-), 1538.55 (C=N str), 1354.50 (N-O of NO2), 1296.60
(Ar.C-N-, str), 762.33 (C-S); 1H NMR (DMSO) δ ppm: 8.57
(s, 1H, imid N-H), 7.94 (d, 2H, 22 & 62-H, phenyl ring on
imid), 7.54 (d, 2H, 22 & 62-H, phenyl ring on thiaz.), 7.32 (d,
2H, 32 & 52-H, phenyl ring on thiaz.), 6.90 (d, 2H, 32 & 52-
H, phenyl ring on imid.), 6.45 (s, 22-H, thiaz.); MS: m/z: 366.16
[M]+.
R1
N
3,6-di(substituted phenyl)
imidazo[2,1-b]thiazole
S
N
R2
3a-i
R2 = Cl, OCH3, NO2
Scheme-I: Synthesis of 3,6-di(substituted phenyl)imidazo[2,1-b]thiazole
derivatives (3a-3i)
(ATCC 32042) at 50 µg/0.1 mL concentration. After 24 h of
incubation at 37 1 °C and 48 h at 28 1 °C, the antibacterial
and antifungal activity respectively was determined by measuring
zones of inhibitions in mm. Standard antibacterial ampicillin
and antifungal miconazole nitrate were used respectively under
similar conditions for comparison. Control test with solvents
were performed for every assay but showed no inhibition of
microbial growth. The responses of organisms to the synthe-
sized compounds were measured as mean of three values and
compared with standards. Standard deviation was also calculated
(Table-2).
Antibacterial and antifungal activity:The antimicrobial
activity of the new compounds was determined in vitro by cup-
plate agar diffusion method using DMSO as solvent [24-26].
Antibacterial activity was determined against Gram-positive
bacteria Staphylococcus aureus (ATCC 11632) and Bacillus
subtilis (ATCC 60711) and Gram-negative bacteria Escherichia
coli (ATCC 10536) and Klebsiella pneumoniae (ATCC 13883),
while antifungal activity against Aspergilus niger(ATCC 1781),
Candida albicans (ATCC 2501) and Cryptococcus neoformans
RESULTS AND DISCUSSION
The formation of intermediates, 2-amino thiazole derivatives
(2a-c) is confirmed by specific IR absorption band for primary
amine at 3360 cm-1 (stretching vibrations) and 1602 cm-1 (bending
vibrations). There is also absorption bands for C=N stretching
at 1534 cm-1 and for C-S-C str. at 770 cm-1. From UV-visible
absorption data, it is observed that the intermediates 2-amino
thiazoles and the title compounds exhibited λmax at 238-244
TABLE-2
MICROBIAL ACTIVITY DATA OF SOME THIAZOLO IMIDAZOLE DERIVATIVES
Zone of inhibition (mm)
Compd.
No.
R1
R2
Antibacterial activity
Antifungal activity
S. aureus
21.66 0.57
NA
19.00 1.00
14.66 0.57
NA
B. subtilis
E. coli
21.00 1.52
NA
K. pneumoniae
17.00 1.73
NA
A. niger
18.33 1.15
NA
C. albicans
16.66 1.52
NA
C. neoformans
15.00 1.73
NA
Cl
Cl
Cl
Cl
OCH3
NO2
Cl
19.33 1.00
NA
18.00 1.73
12.00 1.73
NA
3a
3b
3c
3d
20.66 1.52
10. 66 0.57
NA
17. 33 0.57
NA
17.66 1.15
10.99 0.57
NA
16.33 0.57
NA
14.66 1.52
NA
OCH3
OCH3 OCH3
NA
NA
NA
3e
OCH3
NO2
NO2
NO2
NO2
Cl
OCH3
NO2
16. 33 1.15
20.66 0.57
NA
20.66 1.15
23.33 0.57
–
14. 00 1.73
17.66 0.57
NA
17.33 1.15
19.66 1.15
–
13.66 1.52
21.33 1.52
NA
21.33 0.57
24.00 1.73
–
11.66 0.57
18.00 1.73
NA
17.66 1.52
18.66 1.52
–
08. 66 1.52
14.00 1.00
NA
18.66 1.52
–
NA
15.00 1.73
NA
15.33 1.52
–
24.33 0.57
NA
13.00 1.73
NA
13. 33 0.57
–
23.66 1.52
3f
3g
3h
3i
Ampicillin
Miconazole nitrate
27.66 1.73

2642 Ramamurthy et al.
Asian J. Chem.
4. D. Rodriguez-Lucena, F. Gaboriau, F. Rivault, I.J. Schalk, G. Lescoat
and G.L.A. Mislin, Bioorg. Med. Chem., 8, 689 (2010);
https://doi.org/10.1016/j.bmc.2009.11.057.
5. R.G. Kalkhambkar, G.M. Kulkarni, H. Shivkumar and R.N. Rao, Eur. J.
Chem., 42, 1272 (2007);
https://doi.org/10.1016/j.ejmech.2007.01.023.
6. B.S. Holla, K.V. Malini, B.S. Rao, B.K. Sarojini and N.S. Kumari, Eur.
J. Med. Chem., 38, 313 (2003);
https://doi.org/10.1016/S0223-5234(02)01447-2.
7. F.Azam, I.A. Alkskas, S.L. Khokra and O. Prakash, Eur. J. Med. Chem.,
44, 203 (2009);
https://doi.org/10.1016/j.ejmech.2008.02.007.
8. M. Himaja, K. Rai, K.V.Anish, M.V. Ramana andA.A. Karigar, J. Pharm.
Scient. Innovat., 1, 67 (2012).
9. D. Sharma, B. Narasimhan, P. Kumar,V. Judge, R. Narang, E. De Clercq
and J. Balzarini, Eur. J. Med. Chem., 44, 2347 (2009);
https://doi.org/10.1016/j.ejmech.2008.08.010.
10. D. Zampieri, M.G. Mamolo, L.Vio, E. Banfi, G. Scialino, M. Fermeglia,
M. Ferrone and S. Pricl, Bioorg. Med. Chem., 15, 7444 (2007);
https://doi.org/10.1016/j.bmc.2007.07.023.
11. C. Congiu, M.T. Cocco and V. Onnis, Bioorg. Med. Chem. Lett., 18,
989 (2008);
https://doi.org/10.1016/j.bmcl.2007.12.023.
12. A. Puratchikody and M. Doble, Bioorg. Med. Chem., 15, 1083 (2007);
https://doi.org/10.1016/j.bmc.2006.10.025.
nm and 265-284 nm, respectively. This indicates batho-chromic
shift in the formation of these compounds.
The structures of the title compounds (3a-3i) are charac-
terized by specific IR absorption bands for C=N stretching at
1540-1535 cm-1, Ar-C-N stretching at 1295-1288 cm-1 and
C-S-C stretching at 765-759 cm-1, etc. The presence of other
special functional groups like Cl, OCH3 and NO2 are indicated
by their specific bands (692-690, 1247-1244, 1354-1350 cm-1,
respectively). The structural characteristics were further supported
by 1H NMR and mass-spectral data.
From antibacterial screening study it was observed that
the compounds containing electron withdrawing substituents
on both the rings such as 3a (R1 = Cl, R2 = Cl), 3c (R1 = Cl, R2
= NO2), 3g (R1 = NO2, R2 = Cl) and 3i (R1 = NO2, R2 = NO2)
exhibited significant activity. The compounds containing
electron donating group at R1 and electron withdrawing group
at R2 showed moderate activity, 3d (OCH3, Cl) and 3f (OCH3,
NO2).The remaining compounds showed no activity. Of the
nine compounds screened for antifungal activity, only the
compounds coded 3a, 3c, 3g and 3i displayed significant
fungicidal activity than the remaining compounds, indicates
the significance of electron withdrawing groups.
13. F. Hadizadeh, H. Hosseinzadeh, V.S. Motamed Shariaty, M. Seifi and
S. Kazemi, Iran. J. Pharm. Res., 7, 29 (2008).
14. F. Suzuki, T. Kuroda,Y. Nakasato, H. Manabe, K. Ohmori, S. Kitamura,
S. Ichikawa and T. Ohno, J. Med. Chem., 35, 4045 (1992);
https://doi.org/10.1021/jm00100a009.
Conclusion
Owing to the pronounced biological importance associated
with the drugs containing thiazole and imidazole rings, we
have hereby studied and reported the synthesis and structural
characterization of some thiazolo imidazole derivatives. The
compounds containing electron withdrawing groups on either
ring showed significant antibacerial and antifungal activity.
The insight obtained in this work will be useful for the study
of other structurally modified thiazolo imidazoles.
15. D. Olender, J. Zwawiak,V. Lukianchuk, R. Lesyk,A. Kropacz,A. Fojutowski
and L. Zaprutko, Eur. J. Med. Chem., 44, 645 (2009);
https://doi.org/10.1016/j.ejmech.2008.05.016.
16. N.U. Güzeldemirci and Ö. Kücükbasmaci, Eur. J. Med. Chem., 45, 63
(2010);
https://doi.org/10.1016/j.ejmech.2009.09.024.
17. H. Ding, Z. Chen, C. Zhang, T. Xin,Y. Wang, H. Song,Y. Jiang,Y. Chen,
Y. Xu and C. Tan, Molecules, 17, 4703 (2012);
https://doi.org/10.3390/molecules17044703.
18. J.-H. Park and C.-H. Oh, Bull. Korean Chem. Soc., 31, 2854 (2010);
https://doi.org/10.5012/bkcs.2010.31.10.2854.
ACKNOWLEDGEMENTS
19. A. Andreani, M. Granaiola, A. Leoni, A. Locatelli, R. Morigi and M.
Rambaldi, Eur. J. Med. Chem., 36, 743 (2001);
https://doi.org/10.1016/S0223-5234(01)01266-1.
The authors are thankful to the Management and the Principal,
Visveswarapura Institute of Pharmaceutical Sciences, Bangalore,
India for providing all the facilities to carry out this work.
20. M.B. Tehrani, S. Emami, M. Asadi, M. Saeedi, M. Mirzahekmati, S.M.
Ebrahimi, M. Mahdavi, H. Nadri,A. Moradi, F.H. Moghadam, S. Farzipour,
M. Vosooghi, A. Foroumadi and A. Shafiee, Eur. J. Med. Chem., 87, 759
(2014);
REFERENCES
https://doi.org/10.1016/j.ejmech.2014.10.011.
21. B.S. Furniss, A.J. Hannaford, P.W.G. Smith and A.R. Tatchell, Vogel’s
Textbook of Practical Organic Chemistry, edn 5, p. 1050 (2010).
22. R. Mallikarjuna Rao, G. Nagaraja Reddy and J. Sreeramulu, J. Res. Lib.
Der Pharm. Chem., 3, 301(2011).
1. B.K. Sarojini, B.G. Krishna, C.G. Darshanraj, H. Manjunatha and B.R.
Bharath, Eur. J. Med. Chem., 45, 3490 (2010);
https://doi.org/10.1016/j.ejmech.2010.03.039.
2. G. Turan-Zitouni, S. Demirayak, A. Özdemir, Z.A. Kaplancikli and M.T.
Yildiz, Eur. J. Med. Chem., 39, 267 (2004);
23. M. Senthilraja and P. Giriraj, Int. J. Pharm. Pharm. Sci., 2, 65 (2010).
24. N.C. Desai, D. Dave, M.D. Shah and G.D. Vyas, Indian. J. Chem., 39B, 277
(2000).
https://doi.org/10.1016/j.ejmech.2003.11.001.
3. H.I. El-Subbagh andA.M.Al-Obaid, Eur. J. Med. Chem., 31, 1017 (1996);
https://doi.org/10.1016/S0223-5234(97)86181-8.
25. J. Saravanan and S. Mohan, Asian J. Chem., 15, 67 (2003).
26. S.P. Govinda and S. Mohan, Indian. J. Heterocycl. Chem., 7, 205 (1998).