Synthesis of phthalyl substituted imidazolones and schiff bases as antimicrobial agents

Article abstract of DOI:10.1155/2011/726315

A new series of phthalyl substituted imidazolones (4_a-g) and Schiff bases (5_a-d) were synthesized from 2-methyl-(m-nitro-1,3- dioxo-1,3-dihydro- (2H)-isoindole-2-yl)-5-amino-1,3,4-thiadiazole (3 _a-b). Compounds (3_a-b) were prepared by cyclisation of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2- yl)methyl ethanoate (2) with thiosemicarbazide. 2-(m-nitro-1,3-dioxo-1,3- dihydro-(2H)-isoindole-2-yl) ethanoic acid (1) in presence of thionyl chloride and methanol gave the ester (2) while compound (1) was synthesized by aminolysis of phthalic anhydride with glycine. The compounds were characterized by spectral techniques of IR, 1H NMR, Mass and elemental analysis. All the synthesized compounds (4_a-g) and (5_a-d) were screened for their antibacterial activity against the pathogenic strains E. coli, P. aureus, C. freundii while antifungal activity was evaluated against A. niger, A. flavus, Penicillium sp. and C. albicans.

Full text of DOI:10.1155/2011/726315

ISSN: 0973-4945; CODEN ECJHAO
E-Journal of Chemistry
2011, 8(1), 427-434
http://www.e-journals.net
Synthesis of Phthalyl Substituted Imidazolones and
Schiff Bases as Antimicrobial Agents
PRAMILLA SAH*, NEHA SARASWAT and MANU SETH
Department of Chemistry
J.N.V. University Jodhpur - 342005, India
pramilla_s@yahoo.co.uk
Received 29 April 2010; Accepted 17 July 2010
Abstract: A new series of phthalyl substituted imidazolones (4a–g) and Schiff
bases (5a–d) were synthesized from 2-methyl-(m-nitro-1,3-dioxo-1,3-dihydro-
(2H)-isoindole-2-yl)-5-amino-1,3,4-thiadiazole (3a–b). Compounds (3a–b) were
prepared by cyclisation of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-
yl)methyl ethanoate (2) with thiosemicarbazide. 2-(m-nitro-1,3-dioxo-1,3-
dihydro-(2H)-isoindole-2-yl)ethanoic acid (1) in presence of thionyl chloride
and methanol gave the ester (2) while compound (1) was synthesized by
aminolysis of phthalic anhydride with glycine. The compounds were
1
characterized by spectral techniques of IR, H NMR, Mass and elemental
analysis. All the synthesized compounds (4a–g) and (5a–d) were screened for
their antibacterial activity against the pathogenic strains E. coli, P. aureus, C.
freundii while antifungal activity was evaluated against A. niger, A. flavus,
Penicillium sp. and C. albicans.
Keywords: Isoindole, 1,3,4–Thiadiazole, Imidazolones, Schiff bases, Antibacterial and antifungal
activities.
Introduction
1,3,4–Thiadiazole has a broad spectrum of biological activities i.e. antimicrobial1,
antidepressant2–3, antitubercular3, antidiabetic4, anti HIV5 etc. The imidazolone ring often
appears as the core structure in many drug formulations covering a wide range of
pharmaceutical activities viz. antileshmanial6, antiprotozoal7, antioxidant8, antiinflammatory9
etc. Oxazolones have also received much attention being antimicrobial10, antitubercular11,
antiangiogenic12 etc. It has been reported that Schiff bases act as antibacterial agents due to
their chelating property. These observation prompted us to indirectly cyclise oxazolones and
new Schiff bases with phthalyl substituted 1,3,4–thiadiazoles and evaluate their
antimicrobial action.

428
PRAMILLA SAH et al.
O
C
O
C
O
R
H2O
NH2CH2COOH
O
C
N-CH2-COOH
(1a-b
)
C
R
O
H2O
SOCl2 / methanol
O
C
N-CH2-COOH3
(2a-b)
C
O
R
NH2 NH
H2NC = S
CH3OH
H2O
POCl3
O
C
N
N
(3a-b)
N
CH2
S
NH2
C
O
R
O
R1
CHO
R1
HC = C
N
O
C
C6H5
O
C
O
C
R1
HC = C
N
N
N
N
N
N
CH2
N
N
CH2
N=CH
R
S
S
C
C
O
C
O
R
C6H5
(4a-g)
(5a-d)
R = H, R1 = H = 4a, R = –C6H5 = 5a, R = H, R1 = 4’’’–OH = 4b, R =4’’-OH- C6H4– = 5b, R = H, R1 =2’’’– Cl
= 4c, R =2’’–Cl–C6H4 – = 5c, R = H, R1 = (3’’’–OCH3–4’’’–OH) = 4d, R1 = (3’’–OCH3–4’’–OH) –C6H3– = 5d,
R = NO2, R1 = H= 4e, R = NO2, R1 =2’’’– Cl = 4f, R = NO2, R1 = (3’’’–OCH3–4’’’–OH) = 4g
Scheme 1. Synthesis of imidazolones and Schiff bases
The synthetic route is given in Scheme 1. 2-(m-Nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-
2-yl)-ethanoic acids (1a–b) were prepared by aminolysis of phthalic anhydride with glycine
and further esterification with thionyl chloride and methanol yielded 2-(m-nitro-1,3-dioxo-
1,3-dihydro-(2H)-isoindole-2-yl)-methyl ethanoate (2a–b). Cyclisation of (2a–b) with
thiosemicarbazide in POCl3 gave the phthalyl substituted 1,3,4-thiadiazoles (3a–b).
Compounds (3a–b) were fused with substituted oxazolones initially prepared by the

Synthesis of Phthalyl Substituted Imidazolones
429
Erlenmeyer azlactone synthesis to give the subsequent imidazolones (4a–g). Derivatives
(3a–b) were also reacted with different aromatic aldehydes forming the Schiff bases (5a–d).
All the synthesized compounds were characterized by elemental analysis, IR, H NMR and
1
mass spectrometer techniques (Table 1). The antimicrobial activities of the title compounds
(4a–g) and (5a–d) were evaluated against three bacterial and four fungal strains
Table 1. Analytical data of (4a–g) and (5a–d
)
Elemental analysis, %
Hydrogen
Calc. Found Calc. Found Calc. Found
Compd. Yield M.P.
No.
Molecular
Formula
Carbon
Nitrogen
%
°C
1a
1b
2a
2b
3a
3b
4a
4b
4c
4d
4e
4f
70
65
60
62
65
64
60
70
65
55
62
64
72
70
72
71
74
140 C10H7O4N
155 C10H6O6N2
58.54 58.50 3.41 3.45
48.00 47.85 2.40 2.35
60.27 60.32 4.10 4.12
50.00 50.05 3.03 3.08
50.76 50.66 3.07 3.09
43.27 43.23 2.29 2.31
65.98 66.09 3.46 3.56
63.90 63.99 3.35 3.29
6.83
11.20 11.25
6.39 6.45
6.78
60
80
C11H9O4N
C11H8O6N2
10.60 10.53
21.53 21.47
22.95 23.07
14.25 14.35
13.81 13.89
13.32 13.28
13.04 13.14
15.97 15.90
14.72 14.62
14.84 14.80
16.09 16.19
15.38 15.30
14.64 14.60
14.21 14.24
120 C11H8O2N4S
150 C11H7O4N5S
>320 C27H17O3N5S
>320 C27H17O4N5S
>320 C27H16O4N5SCl 61.65 61.72 3.04 3.14
>320 C28H19O5N5S
>320 C27H16O5N6S
>320 C27H15O5N6SCl 56.79 56.70 2.62 2.70
>320 C28H18O6N6S
90 C18H12O2N4S
140 C18H12O3N4S
62.56 62.50 3.53 3.60
60.44 60.34 2.98 3.01
4g
5a
5b
5c
5d
59.36 59.30 3.18 3.20
62.06 62.26 3.44 3.34
59.34 59.30 3.29 3.22
100 C18H11O2N4SCl 56.47 56.40 2.87 2.92
120 C19H14O4N4S 57.86 57.80 3.55 3.62
Antimicrobial studies
The antimicrobial activity was assayed by agar plate diffusion technique14 at a concentration of 250
and 500 µg/disc. All the synthesized compounds were tested in vitro for their antibacterial activity
against E. coli, Pseudomonas aureus and Cytobacteria freundii. The four species of fungi namely
Aspergillus niger, Aspergillus flavus, Penicillium sp and Candida albicans were taken for antifungal
activity. The plates were incubated for 24 h (antibacterial) and 48 hrs for antifungal activity
respectively at 37 °C. The zone of inhibition was measured in mm (Table 2 and 3). Streptomycin
and griseofulvin were used as the standard drugs for bacterial and fungal activity respectively.
Table 2. Antibacterial activity of compounds (4a–g) and (5a–d) (Zone inhibition in mm)
E. coli
P. aureus
C. freundii
Compound
250 µg
500 µg
19
22
250 µg
500 µg
13
16
250 µg
500 µg
17
19
21
22
22
23
23
18
4a
4b
17
21
22
22
22
24
25
16
19
20
20
12
15
16
16
17
18
19
12
15
17
17
16
18
20
21
21
22
22
16
17
18
18
4c
4d
23
23
24
24
25
17
20
20
17
18
19
19
20
13
16
18
4e
4f
4g
5a
5b
5c
19
20
20
5d
Ref. Std.
20
18
28 24
Control: DMSO (negative); reference standard: streptomycin
24

430
PRAMILLA SAH et al.
Table 3. Antifungal activity of compounds (4a–g) and (5a–d) (Zone inhibition in mm)
Compound
A. niger
24
25
A. flavus
21
24
Penicillium sp.
C. albicans
22
24
25
25
24
25
26
18
19
20
20
28
23
24
25
25
24
25
26
18
19
20
21
20
4a
4b
4c
4d
26
26
25
25
27
27
24
25
4e
4f
28
19
20
22
25
16
18
19
4g
5a
5b
5c
22
30
19
28
5d
Ref. Std.
Control: DMSO (negative); reference standard: griseofulvin
Experimental
All the melting points were taken in open capillary tubes and were uncorrected. IR (KBr)
1
spectra were recorded on FTIR RX 1 Perkin-Elmer spectrophotometer. H NMR were
determined on Bruker DRX 400 MHz Spectrophotometer with DMSO as the solvent.
Mass was recorded on a JEOL–Accu TOF JMS–T100LC mass spectrometer having a
DART source. The substituted azlactones were synthesized following the Erlenmeyer
azlactone synthesis.
Synthesis of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-ethanoic acid (1a–b)
0.5 g Glycine and 1 g phthalic anhydride/m–nitrophthalic anhydride were taken in a test tube
and immersed in an oil bath at 180-185 °C temperature. The contents were thoroughly
stirred during the first 10 min. which finally solidified after 5 min. The solid mass was
filtered, dried and recrystallized with 10% ethanol.
2-(1,3-Dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-ethanoic acid (1a)
IR (KBr) : 1710, 1680 cm–1; 1H NMR δ : 2.33 (s, 2H, CH2), 7.12 - 7.66 (m, 4H, ArH).
2-(m-Nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-ethanoicacid (1b)
IR (KBr) : 1720, 1685, 1532 cm–1; MS (EI) : m/z 251.
Synthesis of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-methyl ethanoate (2a–b)
0.01 mole of compounds (1a–b), 0.01 mol of thionyl chloride and 10-12 mL of methanol
were taken in a round bottomed flask and refluxed for 15 h. The solution was cooled and
neutralized with 10% sodium carbonate. A solid separated out which was filtered, dried and
recrystallized with ethanol.
2-(1,3-Dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-methyl ethanoate (2a)
1
IR (KBr) : 1710, 1726 cm–1; H NMR δ : 2.33 (s, 2H, CH2), 3.52 (s, 3H, CH3), 7.01 – 7.52
(m, 4H, ArH), MS (EI) : m/z 219.
2-(m-Nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-methyl ethanoate (2b)
1
IR (KBr) : 1532, 1715, 1730 cm–1; H NMR δ : 2.33 (s, 2H, CH2), 3.52 (s, 3H, CH3), 7.01-
7.52 (m, 4H, ArH), MS (EI) : m/z 265.

Synthesis of Phthalyl Substituted Imidazolones
431
Synthesis of 2–methyl(m–nitro-1,3–dioxo–1,3–dihydro–(2H)–isoindole–2–yl)5–
amino–1,3,4–thiadiazole (3a–b)
Compound 2 (0.01 mol) and thiosemicarbazide (0.012 mol) were refluxed in presence of
phosphorous oxychloride (0.012 mol) for 3 h. The contents were then poured on to crushed
ice. A solid separated out which was filtered, dried and recrystallized from dioxane.
2–Methyl–(1,3–dioxo–1,3–dihydro–(2H)–isoindole–2–yl)–5–amino–1,3,4–
thiadiazole (3a)
1
IR (KBr) : 1049, 1288, 1373, 1500, 3201 cm–1; H NMR δ : 2.33 (s, 2H, CH2), 5.22 (s, 2H,
NH2), 7.11 – 7.54 (m, 4H, ArH), MS (EI) : m/z 260.
2–Methyl–(m–nitro–1,3–dioxo–1,3–dihydro–(2H)–isoindole–2–yl)–5–amino–1,3,4–
thiadiazole (3b)
1
IR (KBr) : 1052, 1290, 1370, 1510, 1535 cm–1; H NMR δ : 2.38 (s, 2H, CH2), 5.19 (s, 2H,
NH2), 7.05 – 7.69 (m, 3H, ArH), MS (EI) : m/z 306.
Synthesis of 2”–methyl–[m–nitro–1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–
1”,3”,4”–thiadiazol–5”–yl]–4–{benzylidene/substituted benzylidene}–4,5–dihydro–2–
phenyl–imidazol–5–ones (4a–g)
A mixture of 0.01 mol of compounds (3a–b) and appropriate oxazolones were taken in
a round bottom flask and refluxed for 5-6 h in 10-12 mL DMF as the solvent. The
resultant solution was cooled and poured into crushed ice containing small amount of
dil HCl (2N). The product obtained was filtered, dried and recrystallized with
petroleum ether.
2”–Methyl–[1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–thiadiazol–
5”–yl]–4–benzylidene–4,5–dihydro–2–phenyl–imidazol–5–one (4a)
1
IR (KBr) : 1049, 1288, 1373, 1500, 1710, 1791, 2954, 3000–3010 cm–1; HNMR δ : 2.37
(s, 2H, CH2), 6.17 (s, 1H, CH=C), 7.35 - 7.98 (m, 14H, ArH), MS (EI) : m/z 491.
2”–Methyl–[1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–thiadiazol–
5”–yl]–{4”’–hydroxybenzylidene}–4,5–dihydro–2–phenyl–imidazol–5–one (4b)
IR (KBr) : 1049, 1288, 1373, 1500, 1710, 1791, 2954, 3500, 3240 cm–1; 1H NMR δ : 2.30 (s,
2H, CH2), 6.22 (s, 1H, CH=C), 7.35 – 7.82 (m, 13H, ArH), 10.01 (s, 1H, OH), MS (EI) :
m/z 507.
2”–Methyl–[1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–thiadiazol–
5”–yl]–4–{2”’–chlorobenzylidene}–4,5–dihydro–2–phenyl–imidazol–5–one (4c)
IR (KBr) : 1052, 1291, 1365, 1520, 1715, 1795, 2958, 3000–3020 cm–1; 1H NMR δ : 2.29 (s,
2H, CH2), 6.12 (s, 1H, CH=C), 7.22 – 7.98 (m, 13H, ArH), MS (EI) : m/z 525.5, M+2, 528.
2”–Methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–thiadiazol–
5”–yl]–4–{3”’–methoxy–4”’–hydroxy benzylidene}–4,5–dihydro–2–phenyl–imidazol–
5–one (4d)
IR (KBr) : 1055, 1291, 1370, 1520, 1715, 1788, 2376, 2954, 3000–3010, 3240 cm–1;
1H NMR δ : 2.36 (s, 2H, CH2), 3.82 (s, 3H, OCH3), 6.15 (s, 1H, CH=C), 7.17 – 7.79
(m, 12H, ArH), 10.21 (s, 1H, OH), MS (EI) : m/z 537.

432
PRAMILLA SAH et al.
2”–Methyl–[(m–nitro–1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–
thiadiazol–5”–yl]–4–benzylidene–4,5–dihydro–2–phenyl–imidazol–5–one (4e)
1
IR (KBr) : 1050, 1280, 1365, 1515, 1535, 1720, 1788, 2954, 3015–3025 cm–1; H NMR δ :
2.31 (s, 2H, CH2), 6.17 (s, 1H, CH=C), 7.35 – 7.82 (m, 13H, ArH), MS (EI) : m/z 536.
2”–Methyl–[(m–nitro–1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–
thiadiazol–5”–yl]–4–{2”’–chlorobenzylidene}–4,5–dihydro–2–phenyl–imidazol–5–one (4f)
IR (KBr) : 680, 1000, 1281, 1370, 1512, 1535, 1715, 1780, 1791, 2954, 3000–3010 cm–1; 1H NMR
δ : 2.33 (s, 2H, CH2), 6.17 (s, 1H, CH=C), 7.35 – 7.82 (m, 7H, ArH), MS (EI) : m/z 570.5, 572.5.
2”–Methyl–[(m–nitro–1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1”,3”,4”–
thiadiazole–5”–yl]–4–{3’’’–methoxy–4’’’–hydroxybenzylidene}–4,5–dihydro–2–
phenyl– imidazol–5–one (4g)
IR (KBr) : 1044, 1290, 1373, 1378, 1525, 1535, 1700, 1780, 2376, 2954, 3240 cm–1; 1H NMR
δ : 2.29 (s, 2H, CH2), 6.17 (s, 1H, CH=C), 7.35 – 7.82 (m, 11H, ArH), MS (EI) : m/z 566.
Synthesis of 2–methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1,3,4–
thiadiazol–5–yl]–{benzylidene/substituted benzylidene}–imines (5a–d)
0.01 mol of compound (3a) and equimolar ratio of different aromatic aldehydes were
refluxed in 15 mL of acetic acid under anhydrous conditions using sodium acetate (0.82 g)
for 6 h. The reaction mixture was diluted with water, with the subsequent formation of a
solid. It was filtered, dried and recrystallized from ethanol.
2–Methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1,3,4–thiadiazol–
5–yl]–benzylidene imine (5a)
1
IR (KBr) : 1033, 1280, 1288, 1373, 1500, 1710 cm–1; H NMR δ : 2.33 (s, 2H, CH2), 8.97
(s, 1H, N=CH), 7.35 – 7.82 (m, 9H, ArH), MS (EI) : m/z 348.
2–Methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1,3,4–thiadiazol–
5–yl]–{4”–hydroxy benzylidene} imine (5b)
1
IR (KBr) : 1025, 1282, 1288, 1370, 1510, 1710, 3240 cm–1; H NMR δ : 2.25 (s, 2H, CH2),
8.91 (s, 1H, N=CH), 7.21 – 7.78 (m, 8H, ArH), 10.11 (s, 1H, OH), MS (EI) : m/z 364.
2–Methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1,3,4–thiadiazol–
5–yl]–{2”–chloro benzylidene} imine (5c)
1
IR (KBr) : 690, 1033, 1280, 1288, 1373, 1500, 1710 cm–1; H NMR δ : 2.33 (s, 2H, CH2),
8.88 (s, 1H, N=CH), 7.27 – 7.93 (m, 8H, ArH), MS (EI) : m/z 382.5, M+2, 384.5.
2–Methyl–[(1’,3’–dioxo–1’,3’–dihydro–(2’H)–isoindole–2’–yl)–1,3,4–thiadiazol–
5–yl]–{3”–methoxy–4”–hydroxy benzylidene}–imine (5d)
1
IR (KBr) : 1033, 1280, 1288, 1373, 1500, 1710, 2376, 3300 cm–1; H NMR δ : 2.32 (s, 2H,
CH2), 8.88 (s, 1H, N=CH), 7.39 – 7.84 (m, 7H, ArH), 9.98 (s, 1H, OH), MS (EI) : m/z 394.
Results and Discussion
The FTIR spectrum of Compound (1a) gave two characteristic vibrations at 1680 and 1710 cm–1
which were identified as the (C=O, carboxylic) and (C=O, phthalimido) groups respectively.
The structure was further supported by the 1H NMR spectrum which showed two signals

Synthesis of Phthalyl Substituted Imidazolones
433
at δ 2.33 as a singlet integrating for two protons and a multiplet between 7.12 - 7.66 integrated
for four aromatic hydrogens. Conversion to ester (2a) showed the appearance of a new vibration
mode at 1726 cm–1 which was characterized as the carbonyl peak now part of an ester linkage.
Cyclisation of (2a) with thiosemicarbazide in POCl3 gave compound (3a). The FTIR showed
five new stretching vibrations at 1049, 1288, 1373, 1500 and 3201 cm–1. These were
characterized as the C–N, N–N–C, N=C=S, C–S–C, NH2 groups, hence confirming the
cyclisation. The NMR spectrum in DMSO also gave new signals at δ 5.22 which integrated for
two protons of amino group. The active amino group of thiadiazole was then blocked by
appropriate oxazolones/ azalactones. The NMR spectrum of compound (4a) showed a new
downfield signal at δ 6.17 which integrated for a single proton identified as a methene proton.
FTIR also showed new stretching vibrations at 1791 and 3000-3010 cm–1, identified as (C=O,
cyclic) and (C=CH) groups. In another set of reactions, the thiadiazole (3a) was reacted with
benzaldehyde to form (5a). Characteristic vibrations at 1280 cm–1 was visible which confirmed the
presence of (N=CH) linkage. 1HNMR also supported the chemical structure by showing a singlet
at δ 8.91 which integrated for one proton and was identified as the proton of an N=CH group. The
mass spectrum gave the molecular ion peak at 205 (1a), 219 (2a), 260 (3a), 491 (4a) and 348 (5a)
respectively supporting the molecular weight and the molecular formula of these derivatives. The
isotopic peaks in 4c, 4f and 5c confirmed the presence of halogen as a substituent.
Antimicrobial activity
Antibacterial
Two derivatives 4f and 4g while 4e at the higher concentration (500 µg/disc) gave a zone
size between 24-25 mm comparable to the standard drug against E. coli. The other
derivatives 4a, 4b–4d were less active (17-20 mm). Against P. aureus, lesser inhibition
of the bacterial strain was observed (12–19 mm) except 4g which gave the maximum
zone size of 20 mm.
However, against C. freundii, all the imidazolone derivatives were active (21-23 mm)
comparable to the reference drug streptomycin except 4a and 4b respectively (16-19 mm). The
substituted benzylidene imines (5a–5d) were less active against all the bacterial strains (16-20 mm).
Antifungal
Three derivatives 4e, 4f and 4g showed the maximum inhibition comparable to griseofulvin
(27-28 mm) followed by 4a–4d (24-26 mm) against the fungus Aspergillus niger. Against A.
flavus, derivatives 4c, 4d, 4f and 4g gave the zone size of 25 mm followed by 4b and 4e
(24 mm). The derivative 4a was the least active (21 mm).
Maximum inhibition was observed against the penicillin species by 4g (26 mm) while
three derivatives 4c, 4d and 4f were also highly active (25 mm). Least inhibition was
observed when the testing compound was 4a (22 mm). Against C. albicans as the fungal
strain, 4g displayed the maximum inhibition (26 mm) followed by 4c, 4d and 4f (25 mm); 4b
and 4e (24 mm), the least being 4a (23 mm).
The other series i.e. 5a–5d showed a similar behaviour when compared to the
antibacterial activity. All the derivatives showed lesser inhibition against all the fungal
strains. The zone of inhibition ranged between 16-22 mm.
A comparative study has shown that the bacterial strain E. coli was the most inhibited
followed by C. freuindii by the substituted imidazolones, while the growth of all the fungal
strains was inhibited. The structure activity relationship shows that a chloro, nitro, methoxy
and a hydroxy substituent on the phenyl ring of the heterocyclic nucleus enhanced the activity.

434
PRAMILLA SAH et al.
Acknowledgment
1
The authors are thankful to SAIF, CDRI, Lucknow, India for HNMR and Mass spectral
analysis. Thanks are also to the Head, Department of Microbiology, M.D.M. Hospital,
Jodhpur and the Head, Department of Chemistry, J.N.V. University, Jodhpur for the
microbial screening and providing the laboratory facilities.
References
1.
2.
3.
4.
Shabban M R, Saleh T S and Farag A M, Heterocycl., 2009, 78(1), 151-159.
Pattanayak P, Sharma R and Sahoo P K, Med Chem Res., 2009, 18(5), 351-361.
Mishra P, Jakav V and Kashaw S K, J Indian Chem Soc., 2006, 83(1), 1157.
Sashikant R P, Desai N S, Jadhav S G, Koti B C, Pattan J S and Bhat K G, Indian J
Heterocycl Chem., 2008, 17, 288-290.
5.
6.
7.
Shashikant R P, Desai N S, Khade A B, Rasal V P and Paschapur M S, Indian J
Hetero Chem., 2008, 17, 283-284.
Akhtar T, Hameed S, Al-Mosoudi N A and Khan K M, Heteroatom Chem., 2007,
18(3), 316-322.
Smith R C, Reeves J C, Dage R C and Schnettler R A, Biochem Pharmacol., 1987,
36(9), 1457-1460.
8.
9.
Hipura S B, Parikh K A, Merjia B C and Parikh H H, Indian J Chem., 2003, 42(B), 1172.
Bishnoi A, Pandey V K, Saxena R, Joshi M N and Bajpai S K, Indian J Chem., 2002,
41(B), 1978-1979.
10.
11.
12.
Sah P and Kaul V, Indian J Heterocycl Chem., 2009, 19(2), 187.
Prabhavat D M, Asian J Chem., 2001, 13(1), 226.
Sierra-Perron M F, Pierre A, Burbridge N and Guilward N, Bioorg Med Chem Lett.,
2002, 12 (11), 1463-1466.
Vogel’s Textbook of Practical Organic Chemistry, 5th Ed., 1989, Addison Wesley,
Longman Inc., 747.
Varma R S, Iman S A and Nobbles W L, J Pharm Sci., 1973, 62, 140.
13.
14.

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