An efficient green synthesis of 2-arylbenzothiazole analogues as potent antibacterial and anticancer agents

Article abstract of DOI:10.1016/j.bmcl.2015.10.087

We have demonstrated a novel and green approach for the synthesis of 2-substituted benzothiazole analogues. A number of 2-aryl and heteroaryl benzothiazole scaffolds were synthesized using Amberlite IR-120 resin under microwave irradiation. The catalytic

Full text of DOI:10.1016/j.bmcl.2015.10.087

Accepted Manuscript
An efficient green synthesis of 2-arylbenzothiazole analogues as potent anti-
bacterial and anticancer agents
Mohit Chhabra, Sohini Sinha, Swagata Banerjee, Priyankar Paira
PII:
S0960-894X(15)30196-7
DOI:
http://dx.doi.org/10.1016/j.bmcl.2015.10.087
BMCL 23243
Reference:
Bioorganic & Medicinal Chemistry Letters
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Received Date:
Revised Date:
Accepted Date:
6 July 2015
28 October 2015
29 October 2015
Please cite this article as: Chhabra, M., Sinha, S., Banerjee, S., Paira, P., An efficient green synthesis of 2-
arylbenzothiazole analogues as potent antibacterial and anticancer agents, Bioorganic & Medicinal Chemistry
Letters (2015), doi: http://dx.doi.org/10.1016/j.bmcl.2015.10.087
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An efficient green synthesis of 2-arylbenzothiazole analogues as
potent antibacterial and anticancer agents
Mohit Chhabra,† Sohini Sinha,† Swagata Banerjee and Priyankar Paira*
Pharmaceutical Chemistry division, School of advanced sciences, VIT University, Vellore-632014,
Tamilnadu, India
Abstract: We have demonstrated a novel & green approach for the synthesis of 2-substituted benzothiazole
analogues. A number of 2-aryl & heteroaryl benzothiazole scaffolds were synthesized using Amberlite IR-120
resin under Microwave irradiation. The catalytic role and reusability of the resin was well established here. 2-
substituted benzothiazole analogues (3a-l) were also tested against several bacterial strains (S. aureus, E. coli, B.
subtilis, salmonella) and cancer cell lines (MCF-7 & HeLa). The stability of compound 2-Phenyl benzothiazole
(3a) and 2-Pyridin-2-yl-benzothiazole (3k) in GSH (0.01 mM dissolved in DMSO) was measured by UV-Vis
spectroscopy. Compound 3k also shows remarkable fluorescence in MeOH.
Keywords: 2-arylbenzothiazole, green chemistry, amberlite IR-120, antibacterial agents, anticancer
agents
In medicinal chemistry heterocyclic compounds are occupied an important position to create a
relationship between chemical structure and pharmacological activity. For example: Ergotamine,
an indole based alkaloid shows antimigraine activity1 and Cinchonine, the quinolone class of
alkaloid exhibits antimalarial activity.2 Benzothiazole derivatives are one of the most adaptable
group of compounds which frequently occur as various marine and terrestrial natural products.3,4 It
was well recognized that benzothiazole derivatives are extensively applied in non-invasive
diagnosis of Alzheimer’s disease.5,6 These scaffolds are also utilized as an antitubercular,7
antimalarial,8 antihelmintic,9 and antidiabetic10 agents. Additionally, numerous benzothiazole
analogues have also been screened as potential amyloid-binding diagnostic agents in
neurodegenerative disease11,12 and as selective fatty acid amide hydrolase inhibitors.13 It was also
observed that mercapto and hydrazine substituent at second position of benzothiazole ring are
responsible for remarkable anti-bactericidal and anti-inflammatory activity.14,15 Interestingly,
substitution of methoxy group and chloro group at the 4th position of 2-mercaptobenzothiazole
enhances antibacterial activity and antifungal activity respectively.16
Presently, 2-arylbenzothiazole scaffolds have been proved to be a good source for the
discovery of numerous anticancer agents as it is versatile and can be easily designed.
 Corresponding author. Tel.: +91-416-2243091; fax: 91-416-2243092; e-mail: priyankar.paira@vit.ac.in

For instance, 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole was designed at National Cancer
Institute (NCI), which shows potent antitumor efficacy in 60 human cell line screening.17,18 The
effective binding of reactive intermediates with DNA might lead the anti-cancer activity of these
molecules.19 In addition, the fluoro substituted benzothiazole scaffold increases the DNA melting
temperature.20 Kini. S. et. al. has discovered novel 2-aryl benzothiazole derivatives which showed
significant anticancer activities against human cervical cancer cell lines.21 Gupta. S. et. al.
synthesized a series of benzothiazole derivatives and examined for in vitro cytotoxicity against HL-
60 and U-937 cell lines by MTT assay techniques using 5-flurouracil, BCNU, hydroxyurea and
cisplatin as standard drugs.22 Furthermore, 2-(4-aminophenyl)benzothiazole scaffolds have been
discovered as photosensitizers for non-melanoma skin cancers.23 Interestingly, benzothiazole-
substituted 4-hydroxycyclohexadieneone (AW464), has been developed as the prototype of a new
series of “quinols” with potent antitumor activity against renal and colon cancer cell lines that
affects cell-signalling events downstream of the redox regulatory protein thioredoxin.24 The SAR
studies also showed that (i) the presence of free nitrogen is important for the antineoplastic activity,
(ii) the planarity of molecules is important as it promotes DNA-interaction possibility, (iii) the
presence of halogen and alkyl functions at proper positions are important for the activity, owing to
metabolism-related issues. Hence, this unique molecule must be incredibly beneficial in the field of
developing various synthetic anticancer agents.
Over the past few decades, several methods have been developed for the synthesis of
benzothiazole scaffolds. For instance, condensation reaction of 2-amino thiophenol with carboxylic
acids,25 acid chloride,26 aldehydes,27 nitriles,28 β-diketones,29 as well as the metal-free oxidative
cyclization/dehydrogenation of cyclohexanones and thioureas under aerobic condition30 has been
developed. The transition metal catalyzed intramolecular cyclization of 2-halo anilides31 has also
been reported. Additionally, Iodine32 or p-TsOH33 catalyzed benzothiazole synthesis and silica
supported solvent free synthesis of 2-arylbenzothiazole under microwave irradiation,34 have already
been discovered. Nowadays, Several novel approaches like metal free intramolecular cyclization of
2-halo-N-Phenylthioacetamide35 and visible-light driven photoredox catalytic formation of 2-
substituted benzothiazoles through radical cyclization of thioanilides36 has also been developed.
Unfortunately, many of these processes endure limitations, such as extreme reaction conditions, low
yields, dreary workup procedures, and co-occurrence of several side reactions. Thus, the

introduction of green methods to overcome these limitations is still an important experimental
challenge.
Currently, microwave assisted organic synthesis have become a new trend with many
applications in synthesizing the organic molecules.37 Amberlite resin has widely been utilized, not
only as an ion exchange resin but also as an effective catalyst in an organic reaction which is easily
separable from products after the reaction.38 In the course of our research on the development of
efficient methods for the synthesis of bioactive heterocycles, herein we have introduced an
Amberlite IR-120 mediated green synthesis of 2-substituted benzothiazole analogues under
microwave irradiation and evaluated their antibacterial & anticancer activity.
Our purpose was to design and implement an efficient green approach for the synthesis of
bioactive 2-arylbenzothiazole analogues with an ease of purification, characterization and biological
screening. In our present study, microwave assisted organic synthesis was introduced, where
molecules can be built in a fraction of time. Initially, we have added a catalytic amount of
Amberlite IR-120 resin to the equimolar mixture of 2-aminothiophenol (1) and benzaldehyde (2a)
in a Microwave vessel. Then the reaction vessel was subjected to microwave oven for 5 minutes at
245 watts (reaction temperature 85oC). The progress of the reaction was monitored by TLC (3:1
Hexane: Ethyl Acetate). There is a change in colour of the solution was observed after completion
of the reaction. After complete conversion of starting materials into product; the resin was filtered
off and the filtrate was evaporated to dryness in rotor evaporator. The crude product was further
recrystalized from ethyl acetate in hexane (1:3). Yellow needle like crystals of compound 3a was
1
obtained with 95% yield.39 The structure of compound 3a was confirmed by H NMR spectra &
ESI-MS. The optimization of this method was performed with a variety of solid supports & acid
catalysts using 2-aminothiophenol (1) and benzaldehyde (2a) as starting materials (Table 1).
Systematic studies of the reaction conditions using various solid supports and acid catalysts (silica
gel, neutral alumina, K-10 Montmorillonite, Molecular I2, Amberlite IR-120) revealed that
Amberlite IR-120 provided best yield (Table 1) within 5 minutes of reaction. We report here, the
usage of amberlite resin as a reusable acid catalyst for the synthesis of benzothiazole analogues.
This new protocol does not require additional oxidizing agent and the reaction has been carried out
efficiently in a shorter time. Therefore, it has been concluded that Amberlite IR-120 mediated
solvent free techniques are most efficient & selective in terms of reaction time, ease of isolation &

yield of the product. To evaluate the effect of microwave irradiation in comparison with
conventional reaction conditions, a pre-heated oil-bath was used as heat source. Reactions of same
reactants i.e. the mixture of 1 & 2a with resin in oil bath gave the product 3a with significantly
lower yield (70%) in higher reaction time (Table 1). This result clearly indicates that the effect of
microwave is not solely thermal. It could be expected that the application of microwave irradiation
causes easy excitation of electronic energy levels and thus leads to better yield.
Table 1. Optimization of 2-arylbenzothiazole synthesis using various solid supports & acid catalyst
Entrya
Solid support/acid
catalyst
Power of MW (Watt)b
Time (min) Yield (%)
1.
2.
3.
Alumina
Alumina
K-10 Montmorillonite
245
450
245
30
60
30
20
40
40
4.
K-10 Montmorillonite
450
60
60
5.
6.
Silica gel
Silica gel
Molecular I2
Amberlite IR-120
Amberlite IR-120
245
245
245
245
10
15
15
5
75
80
80
95
70
9.
10 c.
11.
In oil bath at 1200 C
60
aAll the reaction was performed with 2-aminothiophenol (1) and benzaldehyde (2a).
bMicrowave Model No. CATA R (Catalyst systems, Pune) has been used for the reaction.
cReaction temperature was 85oC
To establish the scope and generality of this novel approach, reaction of various aryl aldehydes (2a–
l) with amino thiophenol was carried out using the same reaction condition (Scheme 1).
Consequently, a wide variety of aryl benzothiazole (3a-I) possessing different functional groups
was obtained successfully (Table 2). All the products (3a-l) were characterized by spectral and
analytical methods (see ESI†).40 The mass spectra (ESI-MS) of the compounds showed (M+H)+
peaks which are in agreement with their molecular mass. The use of amberlite resin serves a crucial
role; it activates the aldehyde group as acid catalyst followed by imine formation which facilities
the cyclization and aerial oxidation (Scheme 2). To verify the recyclability of the amberlite resin,
after the first cycle, the resin was filtered and washed thoroughly with acetone and MeOH, then
calcined at 100o C. Thereafter the material was reused two times for the synthesis of compound 3a.

However, there was no significant change of the yield of 3a between the first and the third cycle
(Figure 1, 95 vs. 91%) was observed.
NH2
N
S
Amberlite IR-120
Ar
ArCHO
2a-l
SH
MW
245 W, 5-10 min
3a-l
1
a. Ar = benzaldehyde
g. Ar = Indole 2-carboxaldehyde
h. Ar = Napthaldehyde
i. Ar = 2-hydroxy 3-methoxy benzaldehyde
j. Ar = Thiophen 2-carboxaldehyde
k. Ar = Pyridine 2-carboxaldehyde
l. Ar = 2-hydroxy benzaldehyde
b. Ar = 2-Chloro benzaldehyde
c. Ar = 2-Methyl benzaldehyde
d. Ar = 4-Fluoro benzaldehyde
e. Ar = 2-bromo benzaldehyde
f. Ar = Furan 2-carboxaldehyde
Scheme 1: Synthesis of 2-substituted benzothiazole analogues using Amberlite IR-120
Scheme 2: Catalytic role of Amberlite IR-120 for the preparation of 2-substituted benzothiazole
Table 2. Silica gel supported reactions of 2-aminothiophenol (1) with various arylaldehydes (2a–
l) leading to 2-arylbenzothiazole derivatives (3a-l)
Entrya
Aryl aldehyde (2a-l)
2-arylbenzothiazole (3a-l)
Reaction time (min) Yield (%)
1
2
3
4
5
6
5
5
5
10
10
5
95
92
90
92
90
90
2a
2b
2c
2d
2e
2f
3a
3b
3c
3d
3e
3f

7
8
9
10
11
12
10
10
10
5
5
5
88
94
95
95
94
95
2g
2h
2i
2j
2k
2l
3g
3h
3i
3j
3k
3l
aAll the reaction was carried out in presence of catalytic amount of Amberlite IR-120
Figure 1 Reusability of Amberlite IR-120 resin for the synthesis of 2-phenylbenzothiazole (3a)
The cytotoxicity of all the synthesized compounds 3a–l (Table 3) was evaluated using
standard 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) bioassay beside a
panel of cell lines such as human Epitheloid er i ar inoma (HeLa) and human breast carcinoma
cell line (MCF-7) in triplicates. These cells were treated with compounds (3a-l) along with
CisPlatin as a standard positive control at concentration 1 to 100 µM for 24 h. Most of these
benzothiazole derivatives exhibited comparable anticancer activity with cisplatin. DMSO was used
as control where it was not showing any inhibition of cell. In MCF-7 cells, the IC50 values for
benzothiazole derivatives were in the range of 9–28 µM (Table 3). Similarly, in HeLa cells, the
IC50 values for benzothiazole derivatives were found in the range of 15–32 µM.
Current study exposed that MCF-7 cells are more sensitive to all the tested compounds than
HeLa cells. Many anticancer drugs are efficient against MCF-7 and HeLa cells by causing
apoptosis in the course of the expression of caspase-3, generating reactive oxygen species (ROS)
and damaging DNA19. Several Chemotherapeutic agents such as doxorubicin, mitoxantrone,
bleomycin and Cisplatin cause cytotoxicity in MCF-7 and HeLa cells by a similar mechanism.41

Therefore, like other cytotoxic drugs (doxorubicin, mitoxantrone and cisplatin), the synthesized
benzothiazoles may act as potential anticancer agents following similar mechanism. In the
literature, it was found that substitution of strong electronegative atom such as chloro/bromo at the
para position of the aromatic ring increases the lipophilicity of molecules which is accountable for
enhanced cytotoxicity in MTT model.42 In our present study, it was observed that compounds 3b,
3d and 3e having halogen substitution in the benzene ring, shows very significant cytotoxicity in
both the cells.
The structure-activity relationship studies revealed that the introduction of most electronegative
fluorine atom in the para position of the benzene ring (compound 3d) enhanced the cytotoxicity
activity. Whereas, the introduction of electron releasing group (2-Me, 2-OH, 2-OH-3-OMe) in the
benzothiazole derivatives (3c, 3i and 3l) decreased the anticancer efficacy. Cytotoxicity was
noteworthy increased after Substitution of heteroaryl groups at the 2-position of benzothiazole
derivatives (3f, 3g, 3j, 3k). However, compound 3h shows least potency in both the cells may be
because of bulky napthyl group is present at 2-position of benzothiazole ring. Among the tested
compounds, most promising cytotoxicity result was observed with compound 3g in both the cell
lines. Indole group at 2-position of benzothiazole might be effective for the generation of ROS.
Table 3 Preliminary MTT cytotoxicity screening of synthesized benzothiazole derivatives at 24
h of drug exposure
Compound
IC50 (µM)a
MCF-7
18.5±0.88
10.65±0.68
20.45±1.25
9.85±0.72
10.50±0.92
17.62±0.44
9.26±0.98
42.28±0.95
28.6±0.55
22.6±1.18
20.42±0.98
26.8±0.78
00
HeLa
22.12±0.92
18.22±0.65
28.25±1.16
16.6±1.20
17.4±0.68
22.62±1.18
15.21±1.20
48.2±0.85
32.6±0.75
28.46±0.94
27.5±0.66
30.6±0.78
00
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
DMSO
Cisplatin
10±0.6
18±0.5
aIC50 is the concentration at which 50% of cells were undergoing cytotoxic cell death due to
synthesized compound treatment.

Table 4 Anti-bacterial activity of synthesized compounds
Compound
Minimum inhibitory concentration—MIC (µg/mL)
Staphylococcus Escherichia
Bacillus
subtilis
25
12.5
100
12.5
12.5
50
Salmonella
aureus
50
coli
50
25
12.5
100
12.5
12.5
50
3a
3b
3c
3d
3e
3f
12.5
100
6.25
12.5
50
12.5
100
6.25
12.5
50
3.12
>200
>200
12.5
6.25
100
00
25
1.5
1
3.12
>200
>200
12.5
12.5
100
00
10
3
2
3.12
>200
>200
25
12.5
100
00
25
3
2
3.12
>200
>200
25
12.5
100
00
10
3
2
3g
3h
3i
3j
3k
3l
DMSO
Ciprofloxacin
Tobramycin
Gentamycin
Synthesized 2-substituted benzothiazoles 3a-l were screened for their antibacterial activity
(MIC) against various Gram+ and Gram- bacterial stains by agar well diffusion method.43 We
used two strains of Gram+ bacteria i.e. Staphylococcus aureus and Bacillus subtilis and two
strains of Gram- bacteria i.e. Escherichia coli and Salmonella for the screening. The test
compounds were dissolved in dimethylsulfoxide (DMSO) at concentrations of 0.2 mg/mL and
various dilutions were performed by micro dilution technique. Ciprofloxacin, Tobramycin &
Gentamycin were used as standard drugs and DMSO as a control for comparison of antibacterial
activity. The MIC of the synthesized compounds was compared with the standard drugs after 24
h of incubation at 37o C for antibacterial activity. Most of the compounds inhibited the growth of
bacteria with MIC values ranging between 3.12 and 50 µg /ml which is less or equal MIC as
compared to control drug ciprofloxacin (Table 4). The compound 3d containing para fluoro
substituted benzene ring showed very high activity in the MIC range 6.25-12.5 µg/mL.
Compound 3b & 3e are also showing good antibacterial activity in all the strains. However, the
compounds (3c, 3i & 3l) containing electron releasing group showed moderate to no activity.
Among the heteroaryl substituted benzothiazoles, the compound 3g displayed most potency in all

bacterial strains. It exhibited comparable antibacterial profile (MIC ~ 3.12 µg/mL) with the
clinically prevalent drug, Tobramycin against E. coli, B. subtilis and salmonella. Substitution of
Indole moiety at the 2-postion of benzothiazole might play the role in killing mechanism.
However, the compounds referred to in Table 4 did not display better activity than gentamycin.
Antibacterial efficacy of other heteroaryl substituted benzothiazoles are maintaining a certain
order (3k>3j>3f). The Compound 3h containing 2-substituted naphthalene did not show any
activity against both the bacterial strains.
Since the outcomes of the antimicrobial activity of the synthesized 2-substituted
benzothiazole derivatives, the following structure–activity relationships (SAR) can be originated:
a) The high antimicrobial activity of compounds 3b, 3d & 3e in comparison to compound 3a
may be attributed to the presence of halogen functional groups on benzothiazole ring. These
electron withdrawing groups decrease electron density on benzene ring through resonance effect
which might be favorable for high antibacterial activity.
b) The presence of electron releasing groups such as methyl, hydroxyl, methoxy groups
irrespective of position in the benzene rings have shown strong adverse effect on antibacterial
activity and hence the compounds containing these functional groups showed weak or no
activity.
c) The presence of Sulfur & Nitrogen is most important in the heterocycle present in 2-position
of benzothiazole. Therefore, the order of antibacterial efficacy of the heteroaryl substituted
benzothiazoles is 3g>3k>3j>3f>3h. It was found that, compound 3h was not showing any
activity may be because of bulky napthyl group.
In order to be a potential therapeutic agent, a chemical entity has to be stable within the
internal atmosphere of the cells. In this study, the stability in terms of absorbance has been
measured over a period of 48 h. at regular time intervals for 3a and 3k in GSH (0.01 mM
dissolved in DMSO). The results of stability study have been demonstrated in the Figure 2.
When the change in absorbance is negligible from 0 h. to 48 h., the expectancy for the stability
of the compound in that solvent is more. In case of DMSO dissolved sample 3a & 3k in GSH, it
was observed that the absorbance vs wavelength curve obtained at the time of sample preparation
(0 h.) and 48 h. after the preparation are same, except certain minor variations. Hence, both
compounds can be said to be stable in GSH.

Figure 2. UV–vis spectrum of 3a & 3k (c = 1X10-5 M) in GSH (0.01 mM dissolved in DMSO)
Figure 3. Fluorescence emission spectra of compound 3k in different solvent.
The fluorescence spectra of 3k were determined at concentrations of 5x10-6 mol L-1 in different
solvents. Emission spectra of compound 3k are presented in Figure 3. The fluorescence
e itation wa elength (λex/nm) at 230 nm was used for compound 3k. It was observed that
compound 3k shows significant fluorescence intensity at 380 nm in MeOH.
In review, Amberlite IR-120 mediated a novel, general and effective green method
for the preparation of 2-arylbenzothiazole derivatives was established. This technique
allows a great compact of synthetic flexibility and offers the opportunity of synthesizing

newer benzothiazole analogues for anticancer & antibacterial screening. The significant
features of this methodology are that it works with inexpensive and easily available
reactants operating in an environment friendly and mild reaction condition with
operational simplicity. Interestingly, benzothiazole (3g) having indole substitution at 2
position shows most potency in cancer cell line as well as in bacterial strains.
Acknowledgements
The authors are grateful to VIT University for start-up funding. We acknowledge DST, New
Delhi, India for DST-FIST project. We also acknowledge DST-SERB, India for young scientist
grant.
Supplementary data
Supplementary data associated with this article can be found, in the online version, at
http://dx.doi.org/....
†Equal contribution
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39 General procedures for the synthesis of compounds 3a-l: Catalytic amount of Amberlite IR-120
resin was added to the equimolar (1:1) mixture of 2-aminothiophenol (1) and arylaldehyde (2a-l)
in a Microwave vassal. Then the reaction vassal was subjected to microwave oven for 5-10
minutes at 245 watt. The progress of the reaction was monitored by TLC (3:1 Hexane: Ethyl
Acetate) and a change in colour of the solution was observed after the completion of the reaction.
After complete conversion of starting materials into product; the resin was filtered off and the
filtrate was evaporated to dryness in rotor evaporator. The crude product was further recrystalized
from ethyl acetate in hexane (1:3). Yellow, orange or red needle like crystals were found with 90-
95% yield.
2-phenylbenzothiazole [3a]: Aminothiophenol (1) (1 equiv, 1.59 mM, 200 mg, 170 µL) and
benzaldehyde (2a) (1 equiv, 1.60 mM, 160mg) were used. The colour of the mixture was turned

from yellow to orange after stirring for 5 min in MW. The product was obtained as yellow
1
needles (Yield = 95%, Rf = 0.75); mp 115-117oC; H NMR (400 MHz, CDCl3): σ 8.03-8.16 (m,
3H), 7.91 (d, J = 8 Hz, 1H), 7.46-7.60 (m, 4H), 7.34-7.44 (m, 1H); ESI-MS (MeOH): m/z: 212
[M+H]+; HRMS (ESI): m/z calcd for [C13H9NS+H]+: 212.0534 [M+H] +; found: 212.0542.
40 2-benzothiazol-2-yl-6-methoxy-phenol [3i]: Aminothiophenol (1) (1 equiv, 1.59 mM, 200 mg,
170 µL) and 2-hydroxy-3-methoxybenzaldehyde (2i) (1 equiv, 1.6 mM, 240 mg) were used. The
colour of the mixture was turned from light yellow to dark yellow after stirring for 10 min. in
1
MW. The product was obtained as a white solid (Yield = 95%, Rf = 0.88); mp 108-110oC; H
NMR (400 MHz, CDCl3): σ 12.73 (br. s., 1H), 8.01 (d, J = 8.16 Hz, 1H), 7.90 (d, J = 8.03 Hz,
1H), 7.51 (t, J = 7.65 Hz, 1H), 7.41 (t, J = 7.59 Hz, 1H), 7.32 (d, J = 7.91 Hz, 1H), 6.99 (d, J =
7.91 Hz, 1H), 6.90 (t, J = 7.91 Hz, 1H), 3.96 (s, 3H); ESI-MS (MeOH): m/z: 258 [M+H]+; HRMS
(ESI): m/z calcd for [C14H11NO2S+H]+: 258.0589 [M+H]+; found: 258.0585.
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43 (a) Amsterdam, D. In Antibiotics in Laboratory Medicine; Loman, V., Ed., 4th ed.; (b) Williams
and Wilkins: Baltimore, MD, 1996; pp 52–111.

Graphical Abstract
An efficient green synthesis of 2-arylbenzothiazole
analogues as potent antibacterial and anticancer agents
Leave this area blank for abstract info.
Mohit Chhabra,† Sohini Sinha,† Swagata Banerjee and Priyankar Paira*
*Pharmaceutical Chemistry division, School of advanced sciences, VIT University, Vellore-632014, Tamilnadu,
India
NH2
N
S
Amberlite IR-120
Ar
ArCHO
2a-l
neat, MW
245 W, 5-10 min
SH
3a-l
1
Before reaction
After reaction