Synthesis, single crystal XRD and CT DNA / BSA binding studies of new paracetamol derivatives

Article abstract of DOI:10.1016/j.molstruc.2020.127911

N-(4-hydroxy-3-(morpholino(phenyl)methyl)phenyl) acetamide and N-(4-hydroxy-3-(piperidin-1-yl(phenyl)methyl)phenyl) acetamide derivatives have been synthesized via three component reaction of paracetamol, morpholine/piperidine and benzaldehyde. The reacti

Full text of DOI:10.1016/j.molstruc.2020.127911

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Synthesis, single crystal XRD and CT DNA / BSA binding studies of new paracetamol
derivatives
N. Ugin Inba Raj
PII:
S0022-2860(20)30235-0
DOI:
https://doi.org/10.1016/j.molstruc.2020.127911
MOLSTR 127911
Reference:
To appear in: Journal of Molecular Structure
Received Date: 27 August 2019
Revised Date: 5 February 2020
Accepted Date: 13 February 2020
Please cite this article as: N. Ugin Inba Raj, Synthesis, single crystal XRD and CT DNA / BSA
binding studies of new paracetamol derivatives, Journal of Molecular Structure (2020), doi: https://
doi.org/10.1016/j.molstruc.2020.127911.
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Credit Author Statement
Dr.UGIN INBA RAJ N : Conceptualization, Methodology, Software , Data curation,
Writing- Original draft preparation, Visualization, Investigation, Supervision, Software,
Validation, Writing- Reviewing and Editing

Journal of Molecular Structure
journal homepage: www.elsevier.com/ locate/molstruc
Synthesis, Single Crystal XRD and CT DNA / BSA Binding Studies of new
Paracetamol Derivatives
Ugin Inba Raj N
Department of Chemistry, Malankara Catholic College, Mariagiri, Tamil Nadu - 629153, India
ARTICLE INFO
ABSTRACT
N-(4-hydroxy-3-(morpholino(phenyl)methyl)phenyl) acetamide and N-(4-hydroxy-3-(piperidin-
1-yl(phenyl)methyl)phenyl) acetamide derivatives have been synthesized via three component
reaction of paracetamol, morpholine/piperidine and benzaldehyde. The reaction afforded these
novel paracetamol derivatives in moderate to good yield. The solid state structures of some
compounds were examined by X-rays from single crystals .The DNA-binding interactions of the
compounds with calf thymus DNA have been studied by UV, visible, emission studies. The
results were observed hypochromism with red shift suggesting that compounds interact with CT
DNA via intercalation. The protein-binding interactions of the compounds with BSA were
examined by fluorescence, synchronous fluorescence and UV, visible spectroscopic methods.
All the compounds have the ability to bind strongly with BSA and a static quenching mechanism
was observed.
Article history:
Received
Received in revised form
Accepted
Available online
Keywords:
synthesis
Paracetamol
Mannich Base
CT DNA
2019 Elsevier Ltd. All rights reserved
.
BSA
1. Introduction
literature survey reveals that paracetamol and its derivatives are
reported as anticancer, antibacterial, antifungal agents and anti-
arrhythmic drugs.[17, 18] The amino methylated paracetamol
derivatives have been used as intermediates for the synthesis of
malarial drugs such as amodiaquine, isoquine and artemisinin
etc.[19-21]
Multicomponent reaction (MCR) is one in which three or
more reactants react in one reaction condition and produce a
product with substantial portion of all reactants. [1, 2] The
organic chemists paid more attention in designing new MCR and
enlightening known MCR due to single step reaction with high
atom economy and multiple bond forming energy.[3, 4] The
MCR is environment friendly process due to reduction in the
number of steps, time of labour, energy consumption, cost and
isolation of intermediates from product.[5, 6] Several
carbon−heteroatom bond and carbon−carbon bond forming
reactions have been achieved using MCR in one pot.[7, 8] One
such reaction is formation of methylated products through
Mannich reaction[9].[10]
Deoxyribonucleic acid (DNA) is a significant biological
macromolecule which plays a central role in life processes.[22] It
is involved in protein biosynthesis and carries essential genetic
information. Nowadays, study of DNA binding interaction
provides new architectural motifs with high potential probes for
chemical biology and therapeutic agents against many DNA-
related diseases.[23, 24] The literature reveals that many small
molecules like cisplatin, polyamides, polyimides, octahedral
metal complexes and peptide nucleic acid etc bind to DNA.[25-
27] Generally, the type of binding with DNA is of fundamental
importance to take benefit of the drug- DNA binding.
The Mannich reaction is most important for producing
secondary and tertiary amine derivatives via condensation
reaction between active hydrogen compound, amine and non
enolizable aldehyde.[11] The obtained amine derivatives are used
for synthesizing biologically active compounds, natural products
and reactive intermediates.[12, 13] The chiral Mannich bases are
important tool for synthesis of pharmaceutical agents.[14] The
optically active amino alkylated products act as excellent ligands
in asymmetric catalysis.[15]
Serum albumin has been established as the most abundant
protein in the circulatory system and serves as a significant
medium for transporting several endogenous and exogenous
substances.[28, 29] Bovine Serum Albumin (BSA) structurally
resembles to human serum albumin (HSA) and so it is being
widely used to many of the biological studies. [30] Due to the
stability, availability and astonishing binding capacity of serum
albumin it acts as a model for drug protein binding interaction
and gives the fundamental understanding of dug protein binding
interactions.[31]
Worldwide, paracetamol is used as an antipyretic and
analgesic.[16] The benzene ring of the paracetamol undergoes
electrophilic substitution reaction due to the presence of two
activating groups namely, hydroxyl and amide groups. The
______________________________________________
Previously, the paracetamol was amino methylated using
piperidine and formaldehyde (Scheme 1). Generally the rate of
Mannich reaction depends on the nucleophilicity of the active
hydrogen compound and basicity of the reaction medium.[32]
*Corresponding author. Tel: +91-9994091886; Email: nugin86@gmail.com.

2
Journal of Molecular Structure
The amino methylation commonly occurs in phenolic Mannich
In order to improve the yield of 4a, the reaction was
carried out in various solvents such as ethanol, isopropanol,
acetonitrile, DMF, DMSO and water at various heating
conditions (Table 1, entry 5-11). The reaction with isopropanol
as solvent at reflux condition afforded 4a in 72% yield. Thus
entry 6 in Table 1 was found to be the optimized condition for
the formation of the amino aryl methylated paracetamol 4a.
base.[33] But the amino aryl methylation is a difficult process
due to the sterically hindered phenyl group.[34] Here we report
the novel amino arylated paracetamol derivatives via
multicomponent reaction of paracetamol, secondary amine and
benzaldehyde (Scheme 2). The reaction was carried out without
any catalyst under simple reaction conditions. The CT DNA and
BSA binding properties of the compounds were studied using
UV, visible and fluorescence spectroscopic studies.
In order to examine the scope of the reaction, the
reaction with para-substituted benzaldehydes was carried out and
the effect of substitution of aldehyde was studied in the amino
aryl methylated paracetamol derivatives 4 (Table 2). Both
electron withdrawing groups such as chloro and bromo groups
and electron releasing groups such as methyl and methoxy
groups in substituted benzaldehydes afforded the corresponding
product in moderate to good yield (Table 2, entry 1-5).
Benzaldehyde substitution with electron withdrawing groups
resulted in good yield compared to electron releasing groups,
obviously due to the higher electrophilicity of the electron
withdrawing groups substituted in benzaldehyde. The para
substituted chloro benzaldehyde afforded the product in high
yield 77% (Table 2, entry 2).
Previous work [20]:
Scheme 1. Synthesis of amino methylated Mannich base.
Present Work
Table 2. Scope of Aldehyde.
Scheme 2. Synthesis of amino aryl methylated Mannich base.
2. Results and Discussion
2.1. Synthesis
Entry
X
H
Cl
Br
Me
OMe
Product
4a
4b
4c
4d
Yield (%)
Initial effort was focussed on examining the assembly of
paracetamol 3, piperidine 2 and benzaldehyde 1 and to obtain
amino aryl methylated paracetamol. Initially, a mixture of
paracetamol 3, piperidine 2 and benzaldehyde 1 were taken in a
mortar and ground well without solvent for 1 h. The reaction did
not afford any product (Table 1, entry 1) and the mixture of the
above reactants was stirred using methanol as a solvent at room
temperature for 48 h and the reaction did not result in any
product (Table 1, entry 2). When the mixture of the reactants was
refluxed using methanol, the reaction afforded the expected
product 4a in 65% yield (Table 1, entry 3). The heating of the
reactants in neat condition at 85 ºC afforded the product 4a but
only in 40% yield (Table 1, entry 4).
1
2
3
4
5
72
77
73
67
64
4e
Reaction conditions: 1 (5 mmol), 2 (5 mmol), and 3 (5mmol) in solvent (15
mL) at the reflux condition. Isolated yield is tabulated.
Table 1. Optimization of reaction conditions in condensation of
paracetamol, piperidine and benzaldehyde.
Entry
Solvent
Temperature
Time
(h)
1
24
24
8
Yield (%)
(0C )
RT
RT
65
Figure 1: Single crystal XRD of 4a-4e
1
2
3
4
Neat (Grinding)
Methanol
Methanol
Neat
n.d.
n.d.
65
The reaction scope was further tested by replacing the
secondary amine piperidine 2 with morpholine 5. Interestingly,
when the mixture of paracetamol 3, morpholine 5 and
benzaldehyde 3 was refluxed in isopropyl alcohol, it afforded the
corresponding amino aryl methylated product 6a in 74% yield
(Table 3, entry 1). The structure of 6a was characterized by
85
40
5
6
7
8
9
10
Ethanol
Isopropanol
MeCN
DMF
DMSO
78
82
80
85
85
85
24
24
24
24
24
24
68
72
61
67
65
n.d.
1
spectroscopic techniques such as FTIR, H NMR, 13C NMR,
Water
Reaction conditions*: 1 (5 mmol), 2 (5 mmol), and 3 (5 mmol) in solvent (15
mL) at the indicated temperature. Yield is tabulated. n.d. = not detected
DEPT-135 and HRMS and the structure was confirmed by single
crystal XRD (Figure 2).
The reaction is extended to various substituted
benzaldehydes and it was found that morpholine afforded the
corresponding products (6a - 6f) in higher yield (Table 3)
compared to piperidine (4a - 4e). Similar to piperidine,
The compound 4a is characterized by spectroscopic
1
techniques such as FTIR, H NMR, 13C NMR, DEPT-135 and
HRMS and the structure was unambiguously confirmed by single
crystal XRD (Figure 1).

morpholine also showed the same substitution effect in the yield
of the products (Table 3, entry 1-6).
The best packing view for Mannich bases 4c-4e is obtained
along the b-axis forming a tunnel like structure (S5).
Table 3. Scope of Aldehyde.
The Mannich bases 6a & 6e contains only one
symmetry independent molecule is shown in figure S6. The
intramolecular hydrogen bonding was formed five membered
cyclic ring motif and the structure was shown along a axis in
figureS7 and the data were listed in table S4. The amide nitrogen
and oxygen atom are formed intermolecular hydrogen bonding
and the structural motif shown along a axis in figure S8. The one
dimensional linear chain structure was generated. These building
blocks are tailored alternatively and propagate as 3D dimensional
supramolecular architecture along a axis as shown in figure S9.
Entry
X
H
F
Cl
Br
Product
6a
6b
6c
6d
Yield (%)
1
2
3
4
5
6
74
80
78
77
70
67
The crystal structure 6b & 6d obtained with two
independent molecules per unit cell. The displacement ellipsoid
plots of the structures were illustrated in figureS10 and their
hydrogen bonding data were recorded in table S5 respectively. In
the crystal structure the five member cyclic ring motif (Figure
S11) were formed through intermolecular hydrogen bonding via
O(4)-H(4)...N(3). The intermolecular hydrogen bonding was
extended to form supramolecular zig-zag motif with graph set
R22(16). The cumulative effects result in one dimensional
supramolecular chain propagating along a axis as shown in figure
S12. Stability of the crystal 6d was enhanced by C−H…π
interactions as it is demonstrated in figure S13.
Me
OMe
6e
6f
Reaction conditions: 1 (5 mmol), 2 (5 mmol), and 3(5 mmol) in solvent (15
mL) at the reflux condition. Isolated yield is tabulated.
2.3. DNA Binding Studies
2.3.1. DNA Absorbance Titration
The interaction between DNA and compounds were
studied using UV visible spectroscopic methods. The
intercalative mode of binding occurs via strong stacking
interaction between the compound and DNA base pairs leading
to hypochromism. The changes in the absorbance spectra of all
the compounds (4a - 4e & 6a- 6f) upon addition of increasing
concentration of DNA were monitored. The absorption of
compounds 4a - 4e and 6a - 6f at various concentrations of
Figure 2: Single crystal XRD of 6a,6b,6d& 6e
2.2. Crystal structure
The X-ray analyses showed that the molecules of all
five Mannich bases 4a-4e had slightly different structures. There
is only one molecule in an asymmetric unit cell in all the five
Mannich bases. The molecules of these Mannich bases are built
up from three five and six-membered rings connected through a
methine carbon in the molecule and there not in single plane. The
ORTEP diagrams of 4a-4e are shown in figure 1 and the
hydrogen bonds in the structures were listed in table S3.The
supramolecular aggregation for the Mannich bases under
discussion is simple. Mannich bases 4a-4e which could form an
intermolecular hydrogen bond via O-H…N1. The cyclic five
membered motifs were formed for all the compounds and shown
in figure S1. The principal motifs in the crystal structures of
compounds L1&L2 are constructed by means of N1B-H…O1A
and N1A-H…O1B and form a one dimensional linear structure
with graph set of R22(16). Inter and intra molecular 3D
supramolecular motif structure was shown in figure S2& S4. The
formation of the two-dimensional supramolecular structure in the
Mannich bases 4c-4e were readily analysed in terms of the amide
as the basic building block. A pair of intermolecular N(2)-
H(2)...O(2)#1 and N(2)-H(2)...O(2)#1 hydrogen bonds in
Mannich bases 4c-4e generates a zig zag structure (Figure S3).
DNA are displayed in Figure 3, S1 &S2 and the absorption
parameters are shown in Table 4
.
Figure 3. Adbsorbance titration spectra of compounds 4a & 6a.
Table 4. Binding constant, Stern Volmer constant, kapp and ꢀG
values of CT DNA-compound systems.
Compounds
Kb x
-ꢀG kJ
mol-1
Ksv x106
M-1
Kapp
105 M-1
x106 M-1
4a
4b
4c
4d
4e
6a
6b
6c
6d
6e
6f
10.54
8.13
9.77
15.36
20.50
9.10
6.05
6.30
7.75
9.89
34.94
34.29
34.75
35.89
37.01
34.57
33.54
33.64
34.17
34.78
35.03
3.79
3.27
3.73
3.85
3.95
3.03
2.80
2.96
3.02
3.64
3.81
2.49
2.02
2.40
2.90
2.95
1.98
1.89
1.91
1.92
1.99
1.20
10.91

4
Journal of Molecular Structure
The π- π* absorption band of the compounds 4a- 4e and 6a -
6f are shifted to ~2 nm bathochromic shift with hypochromism.
The observed hypochromism suggests that the aromatic
chromophore of the compounds (4a - 4e and 6a - 6f ) interact
with CT DNA via intercalative mode of binding. [35]The binding
constant values are calculated from Wolfee-Shimmer equation
:[36]
[DNA]/(εa- εf) = [DNA]/( εa- εf) +1/kb(εb- εf)
(1)
Where [DNA] is concentration of DNA, εa is the
extinction coefficient of compound for a particular DNA
concentration, εf is the extinction coefficient of free compound,
and εb is the extinction coefficient of compound complex in fully
bound form. The binding constant value is obtained from the
ratio between the slope and intercept of plot [DNA]/[εa-εf] versus
[DNA] (Figure 4) .
Figure 5. Emission spectra compounds 4a & 6a in EB-DNA system.
(λex=520 nm, excitation slit=5nm, λemis slit= 5nm), and Fluorescence
intensity at λemi 608nm for compounds (5ꢁM))
that the EB was replaced by the compounds and EB is moving
from hydrophobic environment to an aqueous environment.[39]
At 598 nm the increase in concentration of compounds 4a - 4e
shows hypochromism up to 67%, 63%, 66%, 67% and 71%
respectively with bathochromic shift 10-15nm. The compounds
6a – 6f exhibit hypochromism up to 61%, 58%, 60%, 61%, 65%
and 65% with a red shift of 10-15 nm. The fluorescence
quenching was analysed by Stern Volmer equation :[40, 41]
F0/F = 1 +Ksv[Q]
(3)
Where F0 and F is the emission intensity in the absence
and presence of the quencher, [Q] is the concentration of
quencher, Ksv is the Stern Volmer quenching constant and Ksv is
the slope that is obtained from a plot of F0/F versus [Q] (Figure
6).
Figure 4. Wolfee-Shimmer plots of compounds 4a -4e and 6a- 6f.
All the compounds binding constant values are almost similar
to EB binding constant (Kb= 1.23 x 105 M-1) suggesting that all
the compounds act as intercalators .[37] The strength of binding
DNA with compounds was compared
using Kb values of
compounds. The high value of Kb indicates the high affinity
towards DNA. The order of binding constant is 4e > 4d > 4a >
4c > 4b and 6f > 6e > 6a > 6d > 6c > 6b. This reveals that the
electron releasing group present in the aromatic chromophore
increases the strength of binding with DNA to a greater extent
compared to the electron withdrawing groups. The free energy
change (ꢀG) for DNA- compounds was calculated using the
following equation:
Figure 6. Stern Volmer plots of compounds 4a - 4e and 6a - 6f.
The Stern Volmer quenching constant (Ksv) values for
4a - 4e were found to be 3.95×106 M-1 - 3.27×106 M-1 and for 6a
- 6f it is found to be 3.81 ×106 M-1 - 2.80 ×106 M-1 . A high
value of Ksv indicates a greater binding ability towards DNA.
Among these series 4 and 6, 4e and 6f have high binding ability
with DNA. Furthermore, the apparent DNA binding constant
(Kapp) was calculated from the following equation :[42]
ꢀG = - 2.303 RT log Kb
(2)
-ꢀG value of compound 4a - 4e was found to be 37.01 kJ mol-
1 - 34.28 kJ mol-1 and 35.02 kJ mol-1 – 33.54 kJ mol-1 for 6a - 6f.
This suggests that compounds - DNA intercalation mode of
binding is a spontaneous process.
KEB [EB] = Kapp [Complex]
(4)
When comparing the 4a & 6a compounds 4a shows that high
binding constant value. Due to the steric effect of morpholine
ring intercalating efficiency was enhance for the 4a compound.
Where [complex] corresponds to 50% reduction of
emission intensity of EB - bound DNA, and KEB = 1.0 × 107 M−1,
[EB] = 5 ꢁM. The Kapp value of the compounds 4a – 4e are 2.49
x106 M-1 , 2.02 x 106 M-1 , 2.40 x 106 M-1 , 2.90 x 106 M-1, 2.95 x
106 M-1 respectively and for 6a - 6f are 1.98 x 106 M-1, 1.89 x
106 M-1, 1.91 x 106 M-1, 1.92 x 106 M-1, 1.99 x 106 M-1, 1.20 x106
M-1 respectively. The higher values for compounds 4e and 6f
indicate that these compounds bind to DNA by intercalation.
2.3.2. Ethidium Bromide Displacement Assay
The effective technique to study the mode of binding of
the compounds with DNA is fluorescence quenching assay using
EB-bound DNA. EB is an intercalative indicator and it forms a
soluble complex with DNA emitting an intense fluorescence.
While adding a second intercalator to this solution, EB is
replaced from EB-bound DNA thereby reducing the intensity of
fluorescence of the system. [38] The fluorescence spectra of EB
bound to DNA in the presence of compounds 4a - 4e and 6a - 6f
are shown in Figure 5, S3 & S4.
2.4. Protein Binding Studies
2.4.1. UV Visible Spectral Studies
The UV visible spectroscopic studies are used to find
the structural changes of proteins and to examine the protein –
compound binding nature. The two types of quenching
mechanism were involved, which are classified as dynamic and
The emission intensity was decreased while adding the
compounds (4a - 4e & 6a - 6f ) to EB- DNA system suggesting

static quenching mechanism.[43]
mechanism refers to compound
The static quenching
fluorophore complex
Table 5. BSA binding parameters of the compounds 4a - 4e &
6a - 6f.
–
formation. The dynamic quenching mechanism refers to
fluorophore and compound interaction in the excited state. The
absorbance spectra of BSA with the addition of compounds (4a-
4e & 6a – 6f) are shown in Figure 7. The addition of compound
to the BSA solution reveals hyperchromism without any shift in
the wavelength. This suggests that in all the compounds,
quenching is initiated by the static quenching mechanism.
Compound
Ksv
x105 M-1
3.83
2.27
2.58
4.34
5.51
2.61
1.44
1.89
2.51
2.71
3.83
Kq
x1012 M-1s-1
3.83
K
x106 M-1
3.82
3.35
3.74
4.23
4.55
3.29
2.68
2.96
3.15
3.64
4.14
n
ꢀG
kJ mol-1
-38.19
-37.86
-38.13
-38.44
-38.63
-37.80
-37.29
-37.55
-37.70
-38.07
-38.39
4a
4b
4c
4d
4e
6a
6b
6c
6d
6e
6f
0.83
0.77
0.84
0.90
0.96
0.76
0.64
0.64
0.69
0.82
0.90
2.27
2.58
4.34
5.51
2.61
1.44
1.88
2.51
2.4.2. Fluorescence Studies of BSA
The emission spectra of BSA with various
concentrations of compounds 4a- 4e and 6a - 6f are shown in
2.71
3.83
Figure 8, S4 & S5
.
quenching.[46] These Kq values suggest that all the compounds
follow the static quenching mechanism. The KSv values show that
4e (5.51x 105 M-1) and 6f (3.83x 105 M-1) have high binding
affinity towards BSA.
Figure 7. UV visible spectrums of BSA and compounds 4a-4e and 6a-6f
Figure 9. Stern Volmer Plot of 4a- 4e and 6a- 6f.
with BSA.
2.4.3. Binding Constant and Number of Binding Sites
Generally small molecules bind with sets of equivalent sites
on macromolecules, with the equilibrium between the bound and
free molecules analysed according to the Scatchard equation
:[47]
log[(F0-F)/F] = log K + n log[Q]
(6)
Where K is the binding constant and n is the number of
binding sites respectively. The value of K and n values are
determined from the slope and intercept of log [(F0- F)/F] versus
log[Q] . The Scatchard plots of compounds 4a - 4e and 6a - 6f
are shown in Figure 10 and the resultant binding constant K and
number of binding sites is shown in Table 5.
Figure 8. Emission spectra compounds 4a & 6a with BSA. (ex=280 nm,
excitation slit=2.5nm, emission slit=2.5nm), and Fluorescence intensity at
emission 350 nm for compounds (5ꢁM))
While increasing the concentration of compounds, the
intensity of emission spectrum of BSA gradually decreases from
73% - 55% for 4a - 4e and from 66% - 45 % for 6a - 6f with a
hypsochromic shift of 2-3 nm. This suggests that all the
compounds bind with BSA effectively and the fluorescence
quenching is defined by the Stern–Volmer relation :[44, 45]
F0/F = 1 + Kq τ0[Q] =1 +Ksv[Q]
(5)
Where F0 and F are the emission intensity in the
absence and presence of the quencher, [Q] is the concentration of
quencher, Ksv is the Stern–Volmer constant and Ksv is the slope
that is obtained from a plot of F0/F versus [Q] (Figure 9). Kq is
bimolecular quenching constant and τ0 is the average lifetime of
BSA. Figure 9 shows the Stern Volmer plots of 4a - 4e and 6a -
6f and Kq and Ksv value are displayed in Table 5.
Figure 10. Scatchard plots of compounds 4a- 4e and 6a- 6f.
The order of binding constant values of 4a - 4e (4.55 x 106 M-1
- 3.82 x 106 M-1) and 6a - 6f (4.14 x 106 M-1- 2.68 x 106 M-1) are:
4e > 4d > 4a > 4c > 4b and 6f > 6e > 6a > 6d > 6c > 6b. The
values of n for all the compounds around 1 indicate that all the
compounds have a single binding site in BSA .[48]
The obtained Kq values of compounds 4a - 4e (5.51 x
1012 M-1 s-1 - 2.27 x 1012 M-1 s-1 ) and 6a - 6f ( 3.83 x 1012
M-1 s-1 - 1.44 x 1012 M-1 s-1) are two-fold higher (2 x 1010 M-
1 s-1 ) than the maximum value possible for diffusion controlled
The free energy changes were analysed when the compounds
bind with BSA and are shown in Table 5. The ꢀG values of 4a -

6
Journal of Molecular Structure
4e are from -38.63 kJ mol-1 to -38.19 kJ mol-1. The ꢀG values of
Negative values of ꢀG indicate that CT DNA and BSA binding
6a – 6f are from -38.39 kJ mol-1 to -37.29 kJ mol-1. Negative
values of ꢀG suggest that binding process of all the compounds
are spontaneous and favourable process .[49]
with all the compounds are spontaneous and favorable process.
4. Experimental Section
4.1. General Procedure for the Synthesis of 4a - 4e and 6a - 6f
2.4.4. BSA Conformational Analysis
The optimization of the reaction and results are presented in
Table 1-3. 5 mmol of paracetamol 3 was dissolved in isopropyl
alcohol solution. To this solution 5 mmol amine (Piperidine 2
/morpholine 5) was added followed by drop wise addition of 5
mmol benzaldehyde 1. The resulting solution was refluxed for 24
hours. The reaction completion was monitored by TLC. The
solvent was removed under reduced pressure and washed with
distilled water and acetone.
Synchronous emission spectroscopy gives information on the
molecular environment in the vicinity of tyrosine and tryptophan
residues present in the BSA. The fluorophore characteristic ꢀλ
value is 15 nm for the tyrosine residues and 60 nm for tryptophan
residues.[50] The Synchronous emission spectra of BSA with
various concentrations of compounds are shown in Figure 11, 12
& S7- S10. In the synchronous fluorescence spectra at ꢀλ = 15
nm, in the BSA solution, increased addition of compounds 4a -
4e and 6a - 6f exhibit the hypochromism of 61% - 45% and
48% -31% respectively with 2-3 nm bathochromic shift. In the
ꢀλ = 60 nm spectra, decreased fluorescence intensity is
observed for 4a – 4e from 70% to 59% .and it is from 61% to
51% for 6a – 6f without any significant shift. The intensity of the
fluorescence is quenched for both the tyrosine and tryptophan
residues.
4.2. DNA Binding Studies
UV visible absorption titration was carried out for all the
compounds at a concentration of 10ꢁM with incremental
addition of CT DNA (5-30 ꢁM in sodium phosphate buffer
solution, pH ∼7.2). The purity of the CT DNA was confirmed by
absorption ratio of CT DNA at 260 and 280 nm which was
found to be 1.9:1 indicating it is sufficiently free from protein.
The concentration of CT DNA was calculated from the known
molar extinction coefficient (ε = 6600 M−1 cm−1) and absorbance
intensity at 260 nm. Ethidium bromide (EtBr) displacement
studies were carried out by monitoring the changes in the
fluorescence intensity at excitation and emission wavelengths of
525 and 602 nm upon
increasing the concentration of
compounds ( 4a - 4e & 6a - 6f) from 5 -50 ꢁM in an aqueous
solution of the EtBr-DNA.
4.3. Protein Binding Studies
Figure 11. Synchronous Fluorescence spectra of BSA - compounds 4a & 6a
with ꢀλ= 15 nm.
In the protein binding studies, the excitation wavelength of
BSA at 280 was fixed and the emission changes were monitored
at ∼348 nm using BSA (0.5 ꢁM) solution prepared in phosphate
buffer (pH ∼7.5). 2.5 mL of BSA solution was titrated with
various concentrations (5 - 50ꢁM) of compounds 4a - 4e and 6a -
6f. Synchronous fluorescence spectral studies with two different
ꢀλ values of 15 and 60 nm were carried out with similar
concentrations.
20
4a: White, Solid, m.p. 210 °C, [α]D = 0.40° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3270, 1555, (O-H) 3149,
(Ar C-H) 3086, (Ali C-H) 2936, 2816, 1443, 1373, (C=O) 1657,
(C-O) 1251, (C-N-C) 1149, 1092, 1065, 1036,1018; H NMR
Figure 12. Synchronous Fluorescence spectra of BSA - compounds 4a & 6a
with ꢀλ= 60 nm.
1
(400 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ ppm: 11.07 (s, 1H),
9.63 (s, 1H), 7.40 (s, 1H), 7.38 (s, 1H), 7.23-7.33 (m, 5H), 6.65
(d, J = 8.40 Hz, 1H), 4.57 (s, 1H), 2.30-2.51 (t, 4H), 1.93 (s, 3H),
1.11-1.53 (m, 6H) 13 C NMR (400 MHz, DMSO-d6 : D2O (~ 20:1
v/v))δ/ppm.: 167.93 (C=O), 152.12 (C-O) , 128.59 (N-C),
141.44, 131.57,129.00, 128.59, 127.74, 127.17, 120.21, 119.67,
116.23 (Ar-C), 72.60 (Methine), 52.53, 26.11 (Pi), 24.18
(Methyl); HRMS (m/z): [M-H] Calc: 323.18 found: 323.22.
These results indicate that conformation changes, increase in
hydrophobicity of the environment and decrease in the polarity of
the fluorophore have occurred.[51, 52]
3. Conclusion
In conclusion, the simple and one pot multi-component
procedure has been described for the synthesis of amino-aryl
methylated paracetamol derivatives. Variation in secondary
amine afforded all the products in moderate to good yield. The
mechanism of the amino aryl methylation of paracetamol has
been explained. The compounds are interacting with CT DNA
via intercalation mode of binding and confirmed through UV
visible and EB displacement assay studies. The binding constant
values were determined. The increasing order of DNA binding
ability is 4b < 4c < 4 a < 4d < 4e; 6b < 6c < 6 d < 6a < 6e < 6f.
Further, the compounds bind with BSA through static mode of
binding. The binding constant values show that BSA binding
ability with compounds is in the order 4b < 4c < 4 a < 4d < 4e; 6b
< 6c < 6 d < 6a < 6e < 6f. The confirmation analysis of BSA
protein binding results revealed that the compounds affect the
microenvironment around the tryptophan and tyrosine residues.
20
4b: White, Solid, m.p. 185 °C, [α]D = 1.00° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3227, 1559, (O-H) 3139,
(Ar C-H) 3067, (Ali C-H) 2927, 2816, 1456, 1386, (C=O) 1659,
1
(C-O) 1258, (C-N-C) 1152, 1108, 1091, 1058, 1036, 1008; H
NMR (300 MHz, DMSO-d6 : D2O (~ 20:1 v/v))δ/ ppm : 10.70 (s,
1H), 9.61 (s, 1H), 7.39 (d, J = 1.50 Hz, 1H), 7.31 (d, J = 7.80 Hz,
2H), 7.24 (d, J = 8.70 Hz, 1H), 6.64 (d, J = 8.70 Hz, 2H), 7.09 (d,
J = 7.80 Hz, 2H), 4.49 (s, 1H), 2.45 (m,4H), 2.24 (s, 3H), 1.73-
13
1.95 (m, 6H); C NMR (300 MHz, DMSO-d6 : D2O (~ 20:1
v/v))δ/ppm: 167.47 (C=O), 151.02 (C-O) , 136.10 (C-Cl),
131.03 (N-C), 140.10, 128.86, 128.26, 127.32, 119.31, 119.09,
115.51 (Ar-C), 70.54 (Methine), 52.60, 23.64, 20.56 (Pi), 23.09
(Methyl); HRMS (m/z): [M+H] Calc: 359.14 found: 359.16.

20
4c: White, Solid, m.p. 192 °C, [α]D = 0.00° at C=0.5 in
119.74, 119.70, 116.08, 116.56, 116.55 (Ar-C) , 70.40 (Methine),
66.70 (O-CH2), 52.51 (N-CH2), 24.19(Methyl); HRMS (m/z):
[M-H] Calc: 343.15, found: 343.15.
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3250, 1548, (O-H) 3144,
(Ar C-H) 3078, (Ali C-H) 2916, 2849, 1447, 1364, (C=O) 1659,
(C-O) 1242, (C-N-C) 1158, 1108, 1069, 1053, 1042,1017; H
NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 10.77 (s,
1H), 9.63 (s, 1H), 7.52 (s, 1H), 7.51 (s, 1H), 7.34 (d, J = 10.00
Hz, 2H), 7.29 (d, J = 5.00 Hz, 2H), 6.66 (d, J = 10.00 Hz, 1H),
4.63 (s, 1H), 2.39 (m, 4H), 1.94 (s, 3H), 1.40-1.52 (m, 6H);
NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 167.94
(C=O), 151.97 (C-O), 120.70 (C-Br), 131.69 (N-C),140.99,
131.85, 130.78, 126.33, 120.2, 119.78, 116.23 (Ar-C) 79.65
(Methine), 52.46, 26.11, 24.31 (Pi), 24.19, (Methyl) ; HRMS
(m/z) : [M+H] Calc: 403.09, found: 403.09.
1
o
20
6c: White, Solid, m.p. 202 C, [α]D = 1.60° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3298, 1560, (O-H) 3212,
(Ar C-H) 3101, (Ali C-H) 2960, 2838, 1493, 1382, (C=O) 1660,
(C-O) 1252, (C-O-C) 1111, (C-N-C) 1156, 1111, 1016; 1H
NMR (400 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 9.81 (s,
1H), 9.59 (s, 1H), 7.39 (s, 1H), 7.31 (dd, J = 8.40, 10.80 Hz, 4H),
13
C
7.22 (d, J = 8.80 Hz, 1H), 6.60 (d, J = 8.80 Hz, 1H), 4.57 (s, 1H),
13
3.53 (s, 4H), 2.24 (t, J=6.80 Hz, 4H), 1.89 (s, 3H);
C NMR
(400 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 167.97 (C=O),
151.31 (C-O), 131.97 (C-Cl), 131.91 (N-C), 140.92, 130.28,
127.05, 119.73, 119.66, 116.04 (Ar-C), 68.80 (Methine),66.71
(O-CH2), 52.44 (N-CH2), 24.21 (Methyl); HRMS (m/z): [M+H]
Calc: 361.12, found: 361.00.
20
4d: White, Solid, m.p. 211 °C, [α]D = -0.60° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3261, 1564, (O-H) 3150,
(Ar C-H) 3089, (Ali C-H) 2922, 2844, 1447, 1392, (C=O) 1648,
(C-O) 1242, (C-N-C) 1152, 1108, 1091, 1053, 1030, 1019; 1H
NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 11.24 (s,
1H), 9.60 (s, 1H), 7.28 (s, 1H), 7.26 (d, J = 5.00 Hz, 2H), 7.24 (d,
J = Hz, 1H), 7.13 (d, J = 5.00 Hz, 2H), 6.65 (d, J = 10.00 Hz,
1H), 4.55 (s, 1H), 2.40 (m, 4H), 2.26 (s, 3H), 1.93 (s, 3H), 1.40-
20
6d: White, Solid, m.p. 218 °C, [α]D = 1.60° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3277, 1548, (O-H) 3200,
(Ar C-H) 3090, (Ali C-H) 2970, 2851, 1441, 1382, (C=O) 1655,
(C-O) 1247, (C-O-C) 1117, (C-N-C) 1134, 1099, 1066, 1023; 1H
NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 9.87 (s,
1H), 9.64 (s, 1H), 7.50 (d, J = 10.00 Hz, 2H), 7.45 (s, 1H), 7.35
(d, J = 10.00 Hz, 2H), 7.29 (d, J = 10.00 Hz, 1H), 6.68 (d, J =
10.00 Hz, 1H), 4.63 (s, 1H), 3.60 (s, 4H), 2.30 (t, J = 10.00 Hz,
4H), 1.96 (s, 3H); 13 C NMR (500 MHz, DMSO-d6 : D2O (~ 20:1
v/v)) δ/ppm: 167.97 (C=O), 151.53 (C-O), 120.49 (C-Br), 131.80
(N-C), 141.35, 131.92, 130.66, 126.98, 119.78, 119.73, 160.06
(Ar-C) , 68.89 (Methine), 66.72 (O-CH2), 52.43 (N-CH2), 24.19
(Methyl); HRMS (m/z): [M-H] Calc: 403.07 found: 403.04.
13
1.50 (m, 6H) ; C NMR (500 MHz, DMSO-d6 : D2O (~ 20:1
v/v) ) δ/ppm: 167.89 (C=O), 152.30 (C-O) ,136.95 (C-Me),
129.54 (N-C), 128.62, 120.32, 119.67, 116.22 (Ar-C) , 72.66
(Methine), 52.39, 26.12, 24.27 (Pi), 24.17, 21.10(Methyl) ;
HRMS (m/z): [M+H] Calc: 339.20, found: 339.30.
20
4e: White, Solid, m.p. 198 °C, [α]D = -1.60° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3278, 1553, (O-H) 3144,
(Ar C-H) 3083, (Ali C-H) 2938, 2861, 1436, 1375, (C=O) 1648,
(C-O) 1231, (C-N-C) 1180, 1152, 1064, 1091; H NMR (500
MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 11.38 (s, 1H), 9.59
(s, 1H), 7.31 (s, 1H), 7.28 (d, J = 10.00 Hz, 2H), 7.24 (d, J =
10.00 Hz, 1H), 7.69 (d, J = 5.00 Hz, 2H), 6.67 (d, J = 5.00 Hz,
1H), 4.53 (s, 1H), 2.40 (m, 4H), 3.72 (s, 3H), 1.96(s, 3H) ,1.39-
1
20
6e: White, Solid, m.p. 223 °C, [α]D = -0.80° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1) : N-H 3311, 1553, (O-H) 3100,
(Ar C-H) 3032, (Ali C-H) 2977, 2855, 1447, 1386, (C=O) 1653,
(C-O) 1242, (C-O-C) 1113, (C-N-C) 1108, 1075, 1030, 1019;
1H NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 10.18
(s, 1H), 9.65 (s, 1H), 7.43 (s, 1H), 7.31 (d, J = 5.00 Hz, 2H), 7.29
(s, 1H), 7.11 (d, J = 10.00 Hz, 2H), 6.68 (d, J = 10.00 Hz, 1H),
4.57 (s, 1H), 3.61 (s, 4H), 2.32 (t, J = 10.00 Hz, 4H), 2.24 (s,
3H) 13 C NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm:
167.95 (C=O), 151.49 (C-O), 136.74 (C-Me), 131.80 (N-C),
138.53, 129.50, 128.48, 127.36, 119.99, 119.62, 116.06 (Ar-C),
70.51 (Methine) ,66.72 (O-CH2), 52.45 (N-CH2), 24.20, 21.08
(Methyl); HRMS (m/z): [M-H] Calc: 339.18 found: 339.30.
13
1.52 (m, 6H); C NMR (500 MHz, DMSO-d6 : D2O (~ 20:1
v/v)) δ/ppm: 167.90 (C=O), 158.96, 152.42 (C-O) , 131.49 (N-
C), 132.81, 129.91, 127.13, 120.43, 119.72, 116.27, 114.34 (Ar-
C), 72.68 (Methine), 55.47 (Methoxy), 52.32, 26.14, 24.26 (Pi),
24.15(Methyl); HRMS (m/z): [M-H] Calc: 353.19 found:
353.19.
20
6a: White, Solid, m.p. 218 °C, [α]D = 0.40° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3299, 1556, (O-H) 3199,
(Ar C-H) 3073, (Ali C-H) 2973, 2947, 1443, 1385, (C=O) 1650,
(C-O) 1252, (C-O-C) 1117, (C-N-C) 1157, 1124, 1023, 1006; 1H
NMR (400 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 10.12 (s,
1H), 9.70 (s, 1H), 7.48 (s, 1H), 7.29-7.43 (m, 5H), 7.21 (t, J =
7.60 Hz, 1H), 6.69 (d, J = 8.80 Hz, 1H), 4.61 (s, 1H), 3.61 (s,
20
6f: White, Solid, m.p. 229 °C, [α]D = -0.20° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3278, 1553, (O-H) 3144,
(Ar C-H) 3083, (Ali C-H) 2938, 2861, 1436, 1375, (C=O) 1648,
(C-O) 1242, (C-O-C) 1108, (C-N-C) 1180, 1152, 1091, 1064; 1H
NMR (500 MHz, DMSO-d6 : D2O (~ 20:1 v/v)) δ/ppm: 10.22 (s,
1H), 9.64 (s, 1H), 7.42 (s, 1H), 7.31 (d, J = 10.00 Hz, 2H), 7.28
(d, J = 5.00 Hz, 1H), 6.87 (d, J = 10.00 Hz, 2H), 6.67 (d, J = 5.00
13
4H), 2.32 (t, J = 10.00 Hz, 4H ) 1.97 (s, 3H); C NMR (400
MHz, DMSO-d6 : D2O (~ 20:1 v/v), δ/ppm: 168.04 (C=O),
151.43 (C-O), 131.80 (N-C), 141.71, 128.94, 128.50, 127.56,
127.35, 119.90, 119.65, 116.05 (Ar-C) , 70.40 (Methine), 66.70
(O-CH2), 52.51 (N-CH2), 24.19 (Methyl); HRMS (m/z): [M-H]
Calc: 325.16, found: 325.17.
Hz, 1H), 4.54 (s, 1H), 3.71 (s, 3H), 3.60 (s, 4H), 2.31 (t, J =
13
10.00 Hz, 4H);
C NMR (500 MHz, DMSO-d6 : D2O (~ 20:1
v/v)) δ/ppm: 167.95 (C=O), 151.47, (C-O), 158.80 (C-OMe),
131.79 (N-C), 133.33,129.71, 127.49, 119.92, 119.55, 116.08,
114.33 (Ar-C), 70.28 (Methine), 66.72 (O-CH2), 52.41(N-CH2),
55.48 (Methoxy), 24.20 (Methyl); HRMS (m/z): [M-H] Calc:
355.17 found: 355.16.
20
6b: White, Solid, m.p. 213 °C, [α]D = -1.40° at C=0.5 in
MeOH, FTIR (KBr) νmax (cm-1): (N-H) 3283, 1559, (O-H) 3150,
(Ar C-H) 3089, (Ali C-H) 2955, 2810, 1456, 1386, (C=O) 1653,
(C-O) 1244, (C-O-C) 1118, (C-N-C) 1152, 1108, 1091, 1058,
1036, 1008; 1H NMR (400 MHz, DMSO-d6 : D2O (~ 20:1 v/v))
δ/ppm: 9.90 (s, 1H), 9.58 (s, 1H), 7.38 (s, 1H), 7.35 (t, J = 10.00
Hz, 2H), 7.21 (d, J = 8.40 Hz, 1H), 7.06 (t, J = 8.40 Hz, 2H), 6.60
(d, J = 8.80 Hz, 1H), 4.59 (s, 1H), 3.53 (s, 4H), 2.25 (t, J = 6.40
Hz, 4H), 1.89 (s, 3H); 13 C NMR (400 MHz, DMSO-d6 : D2O (~
20:1 v/v), δ/ppm: 167.97 (C=O), 151.34 (C-O), 162.82,
160.41(C-F), 131.88 (N-C), 137.95, 130.40, 130.32, 127. 28,
Crystal structure data for 4a (CCDC 1403704),C20 H24 N2 O2
Mr = 324.41, ortho rhombic, P2na21, a = 8.7696(4) A° , b =
19.6874(11) A° , C = 10.4825(6) A° , α = 90°, β = 90° , ϒ = 90° ,
V (Å3)= 1809.81(17), T= 296 K, Z = 4, Dx = 1.191 (mg/m3), ꢁ
(mm-1) = 0.077, F(000) = 696.

8
Journal of Molecular Structure
Crystal structure data for 4b (CCDC 1556655) , C20 H23 Cl
nitrate-catalyzed multicomponent reaction for efficient synthesis
of functionalized tetrahydropyridines, ACS Comb. Sci. 13(2)
(2010) 181-185.
[7] M.S. Singh, S. Chowdhury, Recent developments in solvent-
free multicomponent reactions: a perfect synergy for eco-
compatible organic synthesis, RSC Adv. 2(11) (2012) 4547-4592.
[8] D. Naskar, A. Roy, W.L. Seibel, D.E. Portlock, Novel Petasis
boronic acid–Mannich reactions with tertiary aromatic amines,
Tetrahedron Lett. 44(31) (2003) 5819-5821.
[9] J. Zhen, Y. Dai, T. Villani, D. Giurleo, J.E. Simon, Q. Wu,
Synthesis of novel flavonoid alkaloids as α-glucosidase
inhibitors, Bioorg. Med. Chem. (2017).
[10] L. El Kaim, L. Grimaud, J. Oble, New ortho-quinone
methide formation: application to three-component coupling of
isocyanides, aldehydes and phenols, Org. Biomol. Chem. 4(18)
(2006) 3410-3413.
N2 O2: Mr = 358.85, Monoclinic, P21/c, a =13.5097(6) A°, b
=15.5363(7) A°, C =9.1134(4) A° , α = 90°, β =104.290(9)°, ϒ =
90° , V (Å3) = 1853.63(16), T = 293 K, Z = 4, Dx = 1.286
(mg/m3), ꢁ (mm-1) = 0.222, F(000) = 760.
Crystal structure data for 4c (CCDC 1556656) , C20 H23 Br N2
O2: Mr= 403.31, Monoclinic, P21/c, a = 13.857(2) A°, b =
9.6010(12)A°, C =15.525(2) A°, α = 90°, β = 113.235(6)° , ϒ =
90°, V (Å3)= 1898.0(5), T= 296 K, Z = 4, Dx = 1.411 (mg/m3), ꢁ
(mm-1) = 2.181, F(000) = 832.
Crystal structure data for 4d (CCDC 1556657) ,C21 H26 N2 O2 :
Mr= 338.44, monoclinic, P21/c, a =13.777(3)A°, b =9.635(2) A°,
C =15.495(3) A° , α = 90°, β = 113.939(5)° , ϒ = 90° , V (Å3)=
1880.00(7), T= 293 K, Z = 4, Dx = 1.196 (mg/m3), ꢁ (mm-1) =
0.077, F(000) = 728.
Crystal structure data for 4e (CCDC 1556658), C21 H26 N2 O3 :
Mr= 354.44, monoclinic, P21/c, a =13.9410(6) A°, b =9.7501(4)
A°, C =14.9428(6) A°, α =90°, β =115.5490(10)°, ϒ= 90° , V
(Å3)= 1889.15(14), T= 296 K, Z = 4, Dx = 1.246 (mg/m3), ꢁ
(mm-1) = 0.084, F(000) = 760.
[11] G. Song, M. Jin, Z. Li, P. Ouyang, Asymmetric synthesis of
α, β-diamino acid derivates via Mannich-type reactions of a
chiral Ni (II) complex of glycine with N-tosyl imines, Org.
Biomol. Chem. 9(20) (2011) 7144-7150.
[12] R.D. Wavhale, E.A. Martis, P.K. Ambre, B. Wan, S.G.
Franzblau, K.R. Iyer, K. Raikuvar, K. Macegoniuk, Ł. Berlicki,
S.R. Nandan, Discovery of new leads against Mycobacterium
tuberculosis using scaffold hopping and shape based similarity,
Bioorg. Med. Chem. 25(17) (2017) 4835-4844.
Crystal structure data for 6a (CCDC 1402257) , C19 H22 N2 O3
: Mr = 326.38, monoclinic, P121/c1, a =10.7158(3) A°, b =
17.0330(5) A°, C = 9.4162(3) A° , α = 90°, β = 91.7240(10)°, ϒ=
90°,V (Å3) = 1717.89(9), T = 296 K, Z = 4, Dx = 1.262 (mg/m3),
ꢁ (mm-1) = 0.086, F(000) = 696.
[13] Y.-Q. Wang, X.-Y. Cui, Y.-Y. Ren, Y. Zhang, A highly
enantioselective and regioselective organocatalytic direct
Mannich reaction of methyl alkyl ketones with cyclic imines
benzo [e][1, 2, 3] oxathiazine 2, 2-dioxides, Org. Biomol. Chem.
12(45) (2014) 9101-9104.
Crystal structure data for 6b (CCDC 1556659), C19 H21 F N2
O3 : Mr = 344.38, monoclinic, P21/n, a = 9.2672(5) A°, b
=10.0443(6) A°, C=37.974(2) A° , α = 90°, β = 90.821(4)° , ϒ =
90° , V (Å3)= 3534.40(4), T= 296 K, Z = 8, Dx = 1.294 (mg/m3),
ꢁ (mm-1) = 0.095, F(000) = 1456.
[14] S.M. Kim, J.W. Yang, Organocatalytic asymmetric synthesis
of β 3-amino acid derivatives, Org. Biomol. Chem. 11(29) (2013)
4737-4749.
[15] X. Li, C.-h. Yeung, A.S. Chan, T.-K. Yang, New 1, 3-amino
alcohols derived from ketopinic acid and their application in
catalytic enantioselective reduction of prochiral ketones,
Tetrahedron: Asymmetry 10(4) (1999) 759-763.
[16] A. Bertolini, A. Ferrari, A. Ottani, S. Guerzoni, R. Tacchi,
S. Leone, Paracetamol: new vistas of an old drug, CNS Drug
Rev. 12(3 4) (2006) 250-275.
Crystal structure data for 6d (CCDC 1435610),C19 H21 Br N2
O3 : Mr = 405.29, monoclinic, P21, a = 9.1943(9) A°, b
=10.2358(10) A°, c =19.7750(2) A°, α = 90°, β = 90.487(3)°, ϒ =
90°, V (Å3)= 1861.00(3), T= 293 K, Z = 4, Dx = 1.447 (mg/m3),
ꢁ (mm-1) = 2.229, F(000) = 832.
Crystal structure data for 6e (CCDC 1570809),C20 H24 N2 O3 :
Mr = 340.41, monoclinic, P21/c, a = 11.4005(11) A°, b =
17.3367(16) A°, c = 9.3671(8) A°, α = 90°, β = 90.384(4)°, ϒ =
90°, V (Å3) = 1851.3(3), T = 296 K, Z = 4, Dx = 1.221 (mg/m3),
ꢁ (mm-1) = 0.082, F(000) = 728.
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Crystallographic data for the Structures reported in this paper
have been deposited with the Cambridge Crystallographic Data
Centre (CCDC) as supplementary publication numbers (CCDC
1403704, CCDC 1556655, CCDC 1556656, CCDC 1556657,
CCDC 1556658, CCDC 1402257, CCDC 1556659,
CCDC
1435610 and CCDC 1570809 for 4a, 4b, 4c, 4d, 4e, 6a, 6b 6d and
6e respectively). Copies of the data can be obtained free of
charge from the CCDC (12 Union Road, Cambridge CB2 1EZ,
UK; Tel.:
+
44-1223-336408;Fax:+44-1223-336003;e-mail:
deposit@ccdc.cam.ac.uk;Website http://www.ccdc.cam.ac.uk).
Supplementary Material
FTIR, 1H NMR, 13C NMR, and Mass spectrum for all the
compounds and ORTEP of 4b, 4c, 4d, 4e, 6b, 6d, 6e and 6f and
their crystal data .
The CT DNA and BSA binding studies UV visible, emission and
synchronous fluorescence spectra of 4b, 4c, 4d, 4e, 6b, 6d , 6e
and 6f.

Highlights
ꢀ Amino aryl methylated paracetamol derivatives were synthesized.
ꢀ One pot, non-catalysed and simple MCR gave good yield.
ꢀ Solid state structures of the compounds were studied using single crystal X-ray
diffraction studies.
ꢀ Evaluation of CT DNA and BSA binding properties by spectroscopic methods.

Declaration of interests√
☐ √ The authors declare that they have no known competing financial interests or personal
relationships that could have appeared to influence the work reported in this paper.
☒The authors declare the following financial interests/personal relationships which may be considered
as potential competing interests:
√The authors declare that they have no known competing financial interests or personal relationships
that could have appeared to influence the work reported in this paper.