Synthesis of a series of unsaturated ketone derivatives as selective and reversible monoamine oxidase inhibitors

Article abstract of DOI:10.1016/j.bmc.2015.08.012

We have synthesized three categories of α,β-unsaturated carbonyl derivatives and evaluated their MAO-A and MAO-B inhibitory activities. Among them, compound 10b including α,β-unsaturated ketone group showed the most potent and selective MAO-B inhibitory activity (IC₅₀ human MAO-B 16 nM, >6000-fold selective vs MAO-A) and compound 10b exhibited good reversibility compared with selegiline, a well-known irreversible MAO-B inhibitor. However, both α,β-unsaturated amide and ester derivatives exhibited weaker MAO-B inhibition potencies. The docking studies provided insights into the possible binding modes and the key interaction sites of the synthesized MAO-B inhibitors.

Full text of DOI:10.1016/j.bmc.2015.08.012

Accepted Manuscript
Synthesis of a Series of Unsaturated Ketone Derivatives as Selective and Re-
versible Monoamine Oxidase Inhibitors
Ji Won Choi, Bo Ko Jang, Nam-chul Cho, Jong Hyun Park, Seul Ki Yeon, Eun
Ji Ju, Yong Sup Lee, Gyoonhee Han, Ae Nim Pae, Dong Jin Kim, Ki Duk Park
PII:
S0968-0896(15)00679-3
DOI:
http://dx.doi.org/10.1016/j.bmc.2015.08.012
BMC 12516
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
13 July 2015
11 August 2015
12 August 2015
Please cite this article as: Won Choi, J., Ko Jang, B., Cho, N-c., Hyun Park, J., Ki Yeon, S., Ji Ju, E., Sup Lee, Y.,
Han, G., Nim Pae, A., Jin Kim, D., Duk Park, K., Synthesis of a Series of Unsaturated Ketone Derivatives as Selective
and Reversible Monoamine Oxidase Inhibitors, Bioorganic & Medicinal Chemistry (2015), doi: http://dx.doi.org/
10.1016/j.bmc.2015.08.012
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Synthesis of a Series of Unsaturated Ketone Derivatives as
Selective and Reversible Monoamine Oxidase Inhibitors
Ji Won Choia,b,1, Bo Ko Janga,c,1, Nam-chul Choa, Jong Hyun Parka, Seul Ki Yeona,
Eun Ji Jua, Yong Sup Leec, Gyoonhee Hanb, Ae Nim Paea,d, Dong Jin Kima
and Ki Duk Parka,d,*
a
From the Center for Neuro-Medicine, Korea Institute of Science and Technology, Seoul,
b
c
136-791, Department of Biotechnology, Yonsei University, Seoul 120-749, Department of
d
Pharmacy, College of Pharmacy, Kyung Hee University, Seoul, 130-701, Department of
Biological Chemistry, University of Science and Technology, Daejeon 305-350, Republic of
Korea
1 These authors contributed equally to the work.
Address correspondence to: Ki Duk Park, Ph.D., Center for Neuro-Medicine, Brain Science
Institute, Korea Institute of Science and Technology, 5 Hwarang-ro, 14-gil, Seongbuk-gu,
Seoul 136-791, South Korea; Email: kdpark@kist.re.kr; TEL: 822-958-5132; FAX: 822-958-
5189

Abstract
We have synthesized three categories of α,β-unsaturated carbonyl derivatives and evaluated
their MAO-A and MAO-B inhibitory activities. Among them, compound 10b including α,β-
unsaturated ketone group showed the most potent and selective MAO-B inhibitory activity
(IC50 human MAO-B 16 nM, >6000-fold selective versus MAO-A) and compound 10b
exhibited good reversibility compared with selegiline, a well-known irreversible MAO-B
inhibitor. However, both α,β-unsaturated amide and ester derivatives exhibited weaker MAO-
B inhibition potencies. The docking studies provided insights into the possible binding modes
and the key interaction sites of the synthesized MAO-B inhibitors.

1. Introduction
Monoamine oxidase (MAO) is a flavin adenine dinucleotide (FAD) containing enzymes
localized on the mitochondrial outer membrane and particularly abundant in the liver and
brain.1 MAOs catalyse the oxidative deamination of monoamine neurotransmitters, such as
dopamine, serotonin, and norepinephrine, to their corresponding aldehydes with the
production of hydrogen peroxide (H2O2).2,3 There are two isoforms of MAOs, MAO-A and
MAO-B, which are differentiated by their substrate and inhibitor sensitivity,4-6 and
tissue/cellular distribution.7 MAO-A is mainly located in catecholaminergic neurons and
selectively inhibited by low concentrations of clorgyline (1), whereas MAO-B is primarily
found in serotonergic neurons and astrocytes, and selectively inhibited by L-deprenyl
(selegiline) (Figure 1).8 The activity and the expression levels of MAO-B in the human brain,
but not those of MAO-A, increase with age and particularly its activity is significantly
increased in the substantia nigra (SN) of patients with Parkinson’s diseases (PD). Therefore,
selective MAO-B inhibitors (selegiline (2) and rasagiline (3)) are used solely, or in
combination with the dopamine prodrug levodopa to reduce the metabolic degradation of
dopamine for the symptomatic treatment of PD.9,10 However, the potent and selective MAO-
B inhibitor selegiline (2) shows severe side effects due to its amphetamine metabolites11 and
both selegiline (2) and rasagiline (3) are irreversible MAO-B inhibitors triggering
pharmacological side effects in long term treatment of PD.12

Figure 1. Structures of irreversible MAO inhibitors.
Accordingly, the development of selective reversible MAO-B inhibitors may reduce adverse
effects of irreversible inhibitors and may be promising target for the treatment of other
neurodegenerative diseases. For example, recent study suggested that reversible MAO-B
inhibitors might be effective in treatment for Alzheimer’s disease (AD) by selective inhibition
of astrocytic GABA production.13 On the basis of the recent patent literatures, novel selective
MAO inhibitors have been developed for new therapeutic opportunities such as cancer, hair
loss, muscle dystrophies, cocaine addiction and inflammation along with the classical
therapeutic window.14 In the search for selective reversible MAO-B inhibitors, chalcones
have emerged as a valid scaffold.15,16 Chalcones (4) (1,3-diphenyl-2-propen-1-ones) are
considered as the precursor of flavonoids and abundant in edible plants.17 They consist of
open-chain flavonoids including two aromatic rings and an α,β-unsaturated carbonyl system
and exhibit a broad spectrum of biological activities.18,19 Chimenti et al15 synthesized a series
of chalcones substituted with various functional groups at 2- and 4-position of the A aromatic
moiety and 4’-position of the B aromatic moiety of 4 and tested their inhibitory effects
against human MAO-A and B. While the synthesized chalcone derivatives exhibited human
MAO-B selective inhibitory activity in nM – μM ranges, the most potent compound was
disubstituted in the 2- and 4-position of the A aromatic moiety with hydroxyl and methoxy

groups and in 4’-position of the B aromatic moiety with a chlorine atom. Recently, Morales-
Camilo et al20 reported that all synthesized chalcones with hydroxyl and methoxy groups in
the 2- and 5 (or 6)-position of the A aromatic showed moderate activities (μM ranges). In this
study, we prepared a series of chalcone derivatives substituted with a various functional
group at 2-, 3-, 4-position of B aromatic moiety and evaluated inhibitory activities against
MAO-A and MAO-B. We also examined whether the potent compounds were reversible
inhibitors. Furthermore, we synthesized α,β-unsaturated amide derivatives (5) and α,β-
unsaturated ester derivatives (6), and tested their inhibitory activities to compare with the α,β-
unsaturated carbonyl compounds (Figure 2).
Figure 2. Chemical structures of chalcones, α,β-unsaturated amide derivatives and α,β-
unsaturated ester derivatives.

2. Results and Discussion
2.1. Chemistry
We prepared the substituted chalcones (4) containing an α,β-unsaturated ketone moiety and
modified the ketone position according to two categories: amide or ester. Chalcone
compounds 8–11 were synthesized as previously described.21 Briefly, the substituted chalcone
derivatives were prepared by the Claisen-Schmidt condensation of substituted acetophenones
with aromatic aldehydes using lithium hydroxide hydrate (LiOH∙H2O) as catalyst in ethanol
at room temperature (Scheme 1).
To prepare the α,β-unsaturated amide and ester derivatives 12–20, the free acids 7e–7g were
coupled with the appropriate substituted aniline using the mixed anhydride coupling (MAC)
reaction22 (i.e., isobutyl chloroformate (IBCF), N-methyl morpholine (NMM)) or 4-(4,6-
dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) amide coupling
reaction.22 For 2’-substituted Cl compounds 12b, 13b, 14b and 15b, 2-chloro cinnamoyl
chloride were directly coupled with the desired aniline with triethylamine in DMF (Scheme
2).

Scheme 1. General Procedure for the Preparation of Chalcone Derivatives.

Scheme 2. General Procedure for the Preparation of α,β-Unsaturated Amide and α,β-
Unsaturated Ester Derivatives.
2.2. Inhibitory Activities of the Synthesized Compounds against Monoamine Oxidase
The synthesized compounds were evaluated for inhibitory activities of human MAO-A and
MAO-B using recombinant enzymes. The enzyme inhibition assay on test compounds was
performed using Amplex Red reagents. The inhibitory activities were assayed by
spectrophotometrically measuring the rate of resorufin formation at 570 nm. The inhibitory
potencies (IC50 values) for all synthesized compounds are summarized in Table 1 along with

similar results obtained by the positive control compounds, selegiline and safinamide.
First, we prepared 18 chalcone derivatives that included various functional groups on both
ring A and ring B (Table 1, compounds 811). The first set of compounds 10 included a
methoxy group attached at the 4-position on ring A. Chimenti et al15 reported that the best
results were obtained in the presence of chlorine substituent in the 4’-position on ring B.
However, only chlorine substituted chalcone derivatives for electron-withdrawing group were
evaluated. Thus, we introduced both various electron-withdrawing groups and electron-
donating group into ring B (10a−10i). We observed that substitutions on ring B with an
electron-withdrawing group (CF3, F, or Cl) led to higher inhibitory activities against hMAO-
B than an electron-donating group (OMe). For example, the 2’-substituted CF3, F, and Cl
compounds (10b, 10e, 10f) showed more potent inhibitory activities than the 2’-substituted
OMe compound 10g (10b, IC50 = 16 nM; 10e, IC50 = 56 nM; 10f, IC50 = 69 nM; 10g, IC50 =
419 nM). For the trifluoromethyl-substituted compounds 10b−10d, we found that the 2’-
trifluoromehtyl derivative 10b was more active than the corresponding 3’- and 4’-
trifluoromethyl derivatives 10c and 10d. A similar trend on the inhibitory activities of 2’, 3’,
and 4’ regioisomers was observed in the methoxy-substituted compounds 10g−10i. These
findings suggested that the substitution at 2’-position on ring B in the chalcone derivatives
led to increased inhibitory activity.
Next, we placed a methoxy group at the 2- and 3-positions on ring A (8 and 9). Introduction
of a 2-methoxy or 3-methoxy group on ring A led to decreased inhibitory activities compared
with 4-methoxy substituted regioisomers, indicating that ortho- or meta-methoxy substituents
were not well tolerated. For example, among the 2’-substituted CF3 compounds (8b, 9b and
10b), 10b exhibited more potent inhibitory activities against hMAO-B than the corresponding
2- and 3-methoxy derivatives (10b, IC50 = 16 nM; 8b, IC50 = 253 nM; 9b, IC50 = 2118 nM).

Thus, 10b was the most potent and selective MAO-B inhibitor within the series of the
trifluoromethyl-substituted derivatives (8b, 9b, 10b−10d). The introduction of halogen group
instead of the CF3 group at 2’-position on ring B led to slightly decreased inhibitory activities
(10b, IC50 = 16 nM; 10e, IC50 = 56 nM; 10f, IC50 = 69 nM). When the methoxy group on ring
A was replaced with hydroxyl group for compounds 11, the inhibitory activities were similar
and little weaker. All chalcone derivatives (811) did not inhibit more than 50% of hMAO-A
activity at 100 μM (IC50 > 100 μM).
We introduced either an α,β-unsaturated amide group or α,β-unsaturated ester group instead
of the α,β-unsaturated carbonyl entity of chalcones (12−18 and 19−20, respectively) and
tested their inhibitory activities against hMAOs. Most of compounds with an α,β-unsaturated
amide group (12−18) showed lower activities against hMAO-B than the chalcone derivatives.
Among them, compound 17c exerted the best inhibitory activity against hMAO-B (283 nM).
Interestingly, the 4-hydroxy derivatives 14a and 14b exhibited moderate inhibitory activities
against hMAO-A (9.2 μM and 16.7 μM, respectively). In series of the compounds with α,β-
unsaturated ester group (19−20), we found that 2’-substituted Cl and CF3 compounds 19a and
20a showed better inhibitory activities against hMAO-B than the corresponding α,β-
unsaturated amide derivatives 12a and 13a (19a, IC50 = 5.88 μM; 20a, IC50 = 2.59 μM; 12a,
IC50 = 8.39 μM; 13a, IC50 > 10 μM).
The above structure-activity relation study demonstrated that the synthesized compounds
including α,β-unsaturated carbonyl group led to excellent inhibitory activities against hMAO-
B. Among them, compounds 10b and 10e showed the most potent inhibitory activities against
hMAO-B (IC50 = 16 nM and 56 nM, respectively) and the excellent selectivities against
hMAO-A (IC50(MAO-A)/IC50(MAO-B) > 6000 and >1700, respectively).
Recent study reported chalcone derivatives as Nrf2 activators and compound 10b was a

potent activator of Nrf2 activation both in vitro and in mice.23
Table 1. Inhibitory effects of the synthesized compounds against MAOs
MAO-B
MAO-A
Compound
X
R1
R2
SIb
(IC50, μM)
(IC50, μM)
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
> 100
9.22±0.216
8aa
8b
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
Bond
N
2-OCH3
2-OCH3
3-OCH3
3-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OCH3
4-OH
H
> 10
nd
>395
>126
>47.2
>202
>6250
>689
>502
>1780
>1449
>238
>71.6
nd
2’-CF3
H
0.253±0.008
0.793±0.032
2.118±0.065
0.471±0.009
0.016±0.001
0.145±0.011
0.199±0.017
0.056±0.004
0.069±0.004
9a
9b
2’-CF3
H
10a
10b
10c
10d
10e
10f
10g
10h
10i
2’-CF3
3’-CF3
4’-CF3
2’-F
2’-Cl
2’-OCH3 0.419±0.009
3’-OCH3 1.396±0.013
4’-OCH3
H
> 10
11a
11b
11g
12a
12b
13a
13b
14a
0.182±0.005
0.057±0.003
>549
>1750
>160
>11.9
>35.4
nd
4-OH
2’-CF3
4-OH
2’-OCH3 0.624±0.025
H
2’-CF3
2’-Cl
8.39±0.116
2.82±0.083
> 10
N
H
N
4-OCH3
4-OCH3
4-OH
2’-CF3
2’-Cl
N
> 10
nd
N
2’-CF3
> 10
nd

14b
15a
N
N
N
N
N
N
N
N
O
O
O
4-OH
3-OH
3-OH
3-F
2’-Cl
2’-CF3
2’-Cl
> 10
16.7±0.552
> 100
nd
5.98±0.153
5.21±0.140
3.37±0.068
4.89±0.104
0.283±0.004
0.580±0.005
0.223±0.005
5.88±0.236
2.59±0.128
0.937±0.039
0.112±0.005
0.009±0.001
> 1
>16.7
>19.2
>29.6
>20.4
>353
>172
>448
>17.0
>38.6
>106
15b
> 100
16a
2’-CF3
3’-CF3
4’-CF3
4’-CF3
4’-CF3
2’-CF3
2’-CF3
2’-Cl
> 100
16b
3-F
> 100
16c
3-F
> 100
17a
2-F
> 100
18a
4-F
> 100
19a
H
> 100
20a
4-OCH3
4-OCH3
> 100
20b
> 100
(S)-safinamidec
selegilinec
clorgylinec
> 100
> 1e
0.008±0.001
aInhibition data are reported as IC50 (μM). SI = selectivity index, the selectivity for the MAO-B
b
c
isoform and is given as the ratio of IC50(MAO-A)/IC50(MAO-B). Positive controls; (S)-safinamide:
reversible MAO-B inhibitor, selegiline: irreversible MAO-B inhibitor, clorgyline: irreversible MAO-
A inhibitor. dnd: not determined. eLiterature values: IC50 = 1.7 μM for hMAO-A (ref 15).
2.3. Molecular Docking Studies
We examined the binding modes of the selected compounds for the elucidation of activities
against hMAO-B and selectivities over hMAO-A using Glide SP docking module with the X-
ray crystal structures of hMAO-A (PDB code: 2Z5X) and hMAO-B (PDB code: 2BK3). In
consistent with the experimental data, the docking simulation revealed that highly active
compound 10b having chalcone moiety formed π-π interaction with Tyr326 and Tyr398, and
hydrophobic contacts with the residues of Leu171, Ile199 and Phe343 within the substrate
binding site of hMAO-B (Fig. 3). In contrast, the less active compounds 12a and 19a with an
α,β-unsaturated amide group or α,β-unsaturated ester group interact with Ile316 and Ile199
instead of the interactions with Leu171 and Tyr326. This results indicated that excellent
activity of chalcone moiety such as compound 10b might be related to π-π interaction with

Tyr326 residues within substrate binding pocket of hMAO-B. Glide score displayed good
agreements with inhibitory activities (IC50) in the selected compounds against hMAO-B
(Table 2). As shown in Fig. 4, the binding pose of 10b in the substrate binding site of hMAO-
A was different from hMAO-B because of the difference of structural conformation within
substrate binding cavity. Leu171, Ile199 and Tyr326 residues of hMAO-B are gatekeeper
residues24,25 and corresponding residues in MAO-A are Ile180, Phe208 and Ile335 which
might affect binding selectivity of 10b. Therefore, molecular docking studies suggested that
excellent activity and selectivity of 10b are probably relied on the key interactions with the
Leu171, Ile199 and Tyr326 residues within substrate binding pocket of hMAO-B.
Figure 3. Docking poses of 10b, 12a and 19a into the hMAO-B (A-C) substrate binding sites.
Interacting residues are displayed in line, ligand in sticks, and FAD in sticks green carbon
colored. Water molecules are depicted in red point, the hydrophobic contact in magenta dot
line, and hydrogen bond in green dot line.

Figure 4. Docking poses of 10b into substrate binding sites of the hMAO-B (A) and the
hMAO-A (B). Superimposition of 10b was represented with label of key residue (C).
Molecular surface within substrate binding site was illustrated based on hydrophobicity of
binding cavity.
Table 2. The experimental IC50 and glide scorea for the selected compounds.
MAO-B
Glide score
MAO-A
Glide score
Compound
MAO-B IC50
MAO-A IC50
0.016
8.39
5.88
> 100
> 100
> 100
-10.56
-10.36
-10.19
-7.26
-6.75
-
10b
12a
19a
aGlide score is reported in kcal/mol.
2.4. Reversibility of MAO-B
To examine the reversibility of MAO-B inhibition by active compounds 10b and 10e, we
performed MAO-B inhibition assay after three time washout of MAO-B inhibitors (Fig. S1 in
the Supplementary data). First, the active compounds and reference compound selegiline,
irreversible inhibitor, were examined for their inhibitory activities at 2 μM. All compounds
inhibited hMAO-B activity more than 80%. Next, an aliquot of the enzyme solution with 2

μM of each compound was washed using an effective centrifugation-ultrafiltration method.26
The activities of MAO-B were almost recovered after repeated washout of MAO-B inhibitors
10b and 10e, indicating that they are fully reversible inhibitors. However, irreversible
inhibitor selegiline showed no recovery of hMAO-B activity in the same assay (Fig. 5). These
results suggest that the compounds 10b and 10e are reversible inhibitors of hMAO-B and
have considerable advantages compared to irreversible inhibitors which may show safety
issues and pharmacological side effects.12,27 This data disagree with that obtained by
Chimenti et al.,15 who reported the chalcone derivatives are irreversible inhibitor of hMAO-B
as shown by the lack of enzyme activity restoration after repeated washing. This discrepancy
is probably due to the different structures. The α,β-unsaturated carbonyl of the compounds
10b and 10e may not react with nucleophiles like thiol of close cysteine residue in active site.
Reversibility and irreversibility of MAO-B inhibitors
120
100
80
control
selegiline (2 M)
10b (2 M)
10e (2 M)
60
40
20
0
before washout
after washout
Figure 5. Reversibility of hMAO-B inhibition of compounds 10b and 10e

2.5. Hydrogen Peroxide Scavenging Capacity
Recent study reported that methoxy chalcone derivatives have the ability to scavenge
hydrogen peroxide.28 Hydrogen peroxide is produced by MAO-B enzyme activation and its
value is quantified to determine MAO-B activity. We examined the hydrogen peroxide
scavenging capacities of compounds 10b and 10e to determine whether their MAO-B
inhibitory activities were caused by direct scavenging capacity of H2O2. Hydrogen peroxide
scavenging activity was measured by peroxidase-based assay system. The scavenging
capacity of MAO-B inhibitors 10b and 10e on hydrogen peroxide was shown in Figure 6,
compared with EGCG (epigallocatechin-3-gallate), well known hydrogen peroxide scavenger.
Positive control compound EGCG showed H2O2 scavenging activity in dose dependent
manner. On the contrary, almost no H2O2 scavenging activity was observed for compounds
10b and 10e up to 50 μM, indicating that the compounds 10b and 10e did not affect amount
of hydrogen peroxide produced by MAO-B activity.
Figure 6. Hydrogen peroxide scavenging capacity of compounds 10b and 10e.

3. Conclusion
In the present work, we have synthesized and evaluated a series of α,β-unsaturated ketone,
α,β-unsaturated amide and α,β-unsaturated ester derivatives as inhibitors of hMAO isoforms
A and B. The synthesized α,β-unsaturated ketone derivatives showed potent and selective
activity toward the B isoform. Significantly effective activity was observed for many of the
correlated scaffold. Comparison SAR of methoxy substituted aryl regioisomers (2-, 3-, 4-
position) on ring A showed that 4-methoxy derivatives exhibited the most potent MAO-B
inhibitory activity. In addition, electron-withdrawing group substitution on ring B led to
increase of MAO-B inhibitory activity. The most potent compounds 10b and 10e exerted
excellent selectivities against MAO-B and exceptional reversibilities. Molecular docking
study indicated the significant hydrophobic contacts of phenyl ring of these compounds with
Leu171, Ile199 and Tyr326 residues in substrate binding pocket of MAO-B.

4. Experimental Section
General Methods. Melting points were determined in open capillary tubes using an Opti
melt melting point apparatus (Stanford Research System, Inc.) and are uncorrected. NMR
spectra were obtained at either 400 MHz (1H) and 100 MHz (13C) or 300 MHz(1H) and 75
MHz (13C) using TMS as an internal standard. Chemical shifts (δ) are reported in parts per
million (ppm) from tetramethylsilane (TMS). The low-resolution mass spectrum was
performed on a liquid chromatograph mass spectrometer (SHIMADZU Excellence in Science,
LCMS-2020). Reactions were monitored by analytical thin-layer chromatography (TLC)
plates (Merck, Cat # 1.05715) and analyzed with 254 nm light. The reactions were purified
by column chromatography using silica gel (Merck, Cat # 1.07734& 1.09385). All chemicals
and solvents were reagent grade and used as obtained from commercial sources without
further purification. Yields reported are for purified products and were not optimized.
1
Compounds were checked by TLC, H and 13C NMR, LR-MS. The TLC, NMR and the
analytical data confirmed the purity of the products was ≥ 95%.
General Procedure for the Chalcone Derivatives (Method A). To an ethanol solution of
the substituted acetophenones (1.0 equiv) was added LiOH∙H2O (1.0 equiv). The reaction
mixture was stirred for 15 min at room temperature and then treated with the desired
benzaldehyde (1.2 equiv). The mixture was stirred for 2 h at room temperature. The reaction
mixture was quenched with H2O (100 mL) and then diluted with EtOAc (200 mL) and
washed with H2O (2  200 mL) and brine (200 mL). The organic layer was dried with
anhydrous Na2SO4 and concentrated in vacuo. The residue was purified by column
chromatography on SiO2.

General Procedure for the DMTMM amide coupling reaction (Method B). To an
anhydrous DMF solution of the acids were added the desired anilines (1.1 equiv), and
DMTMM (1.1 equiv).22,29 The reaction mixture was stirred for 2−4 h at room temperature
and diluted with EtOAc (200 mL) and then washed with water (100 mL). The combined
organic layers were dried with anhydrous Na2SO4, and concentrated in vacuo. The residue
was purified by column chromatography on SiO2.
General Procedure for Mixed Anhydride Coupling Reaction (Method C). To an
anhydrous THF solution at −78 °C in dry ice and acetone bath) of the acids was added N-
methylmorpholine (NMM) (1.5 equiv), stirred for 2 min, isobutylchloroformate (IBCF) (1.27
equiv), stirred for 5 min. The reaction mixture was treated with the desired anilines (1.2
equiv), allowed to warm to room temperature and further stirred for 2–4 h. The salts were
filtered and rinsed with THF and the filtrate was concentrated in vacuo. The mixture was
diluted with EtOAc (200 mL) and washed with water (100 mL). The combined organic layers
were dried with anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by
column chromatography on SiO2.
General Procedure for Schotten-Baumann Reaction (Method D). To an anhydrous DMF
solution of 7h was added triethylamine (TEA) (1.5equiv) and the desired anilines (1.2 equiv),
stirred for 1–3h at room temperature. The reaction mixture was diluted with EtOAc (200 mL)
and then washed with water (100 mL). The combined organic layers were dried with
anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by column
chromatography on SiO2.

Preparation of (E)-1-(2-methoxyphenyl)-3-phenylprop-2-en-1-one (8a). Using Method A,
7c (0.92 mL, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and benzaldehyde (0.81 mL, 8.0
mmol) in EtOH (25 mL) gave 8a as a yellow oil (0.83 g, 52%); Rf = 0.25 (n-hexane/EtOAc
1
9/1); H NMR (400 MHz, DMSO-d6) δ 3.88 (s, OCH3), 7.08 (t liked due to dd, J = 7.36,
ArH), 7.20 (d, J = 8.32 Hz, ArH), 7.41 – 7.78 (m, 7ArH, 2trans H), 7.72 – 7.78 (m, 2ArH);
13C NMR (75 MHz, DMSO-d6) δ 56.3 (OCH3), 112.8, 121.0, 127.5, 129.3, 129.5, 130.1,
130.9, 133.5, 135.1, 158.2, 192.6 (ArC, CH, CO).
Preparation of (E)-1-(2-methoxyphenyl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one
(8b). Using Method A, 7c (0.92 mL, 6.7mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 2-
(trifluoromethyl)benzaldehyde (1.05 mL, 8.0 mmol) in EtOH (25 mL) gave 8b as a yellow oil
1
(0.82 g, 40%); Rf = 0.20 (n-hexane/EtOAc 9/1); H NMR (400 MHz, DMSO-d6) δ 7.10 (t
liked due to dd, ArH), 7.23 (d, J = 8.24 Hz, ArH), 7.52 – 7.67 (m, 4ArH), 7.76 – 7.83 (m,
13
3ArH), 8.11 (d, J = 7.8 Hz, ArH); C NMR (75 MHz, DMSO-d6) δ 56.2 (OCH3), 112.7,
121.0, 124.5 (q, JC-F = 272.3, CF3), 126.6 (q, JC-F = 5.58 Hz), 127.9 (q, JC-F = 29.5 Hz), 128.6,
128.7, 130.2, 130.6, 131.3, 133.4, 134.0, 136.8 (d, JC-F = 1.91 Hz), 162.3 (ArC, CH), 192.1
(CO).
Preparation of (E)-1-(3-methoxyphenyl)-3-phenylprop-2-en-1-one (9a). Using Method A,
7b (0.91mL, 0.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and benzaldehyde (0.81 mL, 8.0
mmol) in EtOH (25mL) gave 9a as a light yellow soid (0.94 g, 59%); Rf = 0.25 (n-
o
1
hexane/EtOAc 9/1); mp: 48.0 ‒ 49.5 C; H NMR (400 MHz, DMSO-d6) δ 3.88 (s, OCH3),
7.25 – 7.27 (m, 4ArH), 7.47 – 7.53 (m, 4ArH), 7.66 (s, ArH), 7.77 – 7.81 (m, ArH, trans H),
7.91 – 7.97 (m, 2ArH, trans H); 13C NMR (75 MHz, DMSO-d6) δ 55.8 (OCH3) 113.5, 119.6,
121.5, 122.6, 129.4, 129.4, 130.4, 131.1, 135.1, 139.5, 144.6, 160.0 (ArC, CH), 189.4 (CO).
Preparation of (E)-1-(3-methoxyphenyl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one

(9b). Using Method A, 7b (0.91 mL, 6.7 mmol), and 2-(trifluoromethyl)benzaldehyde (1.05
mL, 8.0 mmol) in EtOH (25mL) gave 9b as a light yellow solid (1.12 g, 54%); Rf = 0.20 (n-
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hexane/EtOAc 9/1); mp: 59.0 ‒ 60.5 C; H NMR (400 MHz, DMSO-d6) δ 3.89 (s, OCH3),
7.28 – 7.30 (m, ArH), 7.66 – 7.70 (m, ArH, trans H), 7.79 – 7.86 (m, 2ArH, trans H), 8.36 (d,
J = 7.8 Hz, ArH); 13C NMR (75 MHz, DMSO-d6) δ 55.5 (OCH3) 113.6, 119.7, 121.5, 124.5
(q, JC-F = 272.4 Hz, CF3), 126.3 (q, JC-F = 5.7 Hz), 126.4, 128.1 (q, JC-F = 29.5 Hz), 129.1,
130.2, 130.5, 133.0, 133.3, 138.4 (d, JC-F = 1.7 Hz), 139.0, 160.0 (ArC, CH), 189.0 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-phenylprop-2-en-1-one (10a). Using Method A,
7a (1.00 g, 6.7 mmol), and benzaldehyde (0.81 mL, 8.0 mmol) in EtOH (25mL) gave 10a as
a white solid (1.23 g, 78%); Rf = 0.20 (n-hexane/EtOAc 9/1); mp: 109.0 – 111.5 oC; 1H NMR
(400 MHz, CDCl3) δ 3.89 (s, OCH3), 6.99 (d, J = 8.8 Hz, 2ArH), 7.41 – 7.43 (m, 3ArH),
7.54 (d, J = 15.7 Hz, trans H), 7.65 – 7.66 (m, 2ArH), 7.85 (d, J = 15.7 Hz, trans H), 8.04 (d,
13
J = 8.8 Hz, 2ArH); C NMR (75 MHz, CDCl3) δ 55.5 (OCH3) 113.9, 122.0, 128.4, 128.9,
130.3, 130.8, 131.1, 135.1, 143.9, 163.5 (ArC, CH), 188.7 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one
(10b). Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 2-
(trifluoromethyl)benzaldehyde (1.05 mL, 8.0 mmol) in EtOH (25 mL), gave 10b as a yellow
solid (1.6 g, 78%); Rf = 0.10 (n-hexane/EtOAc 9/1); mp: 86.5 – 87.5 oC; 1H NMR (400 MHz,
CDCl3) δ 3.90 (s, OCH3), 6.99 (d, J = 8.9 Hz, 2ArH) , 7.42 (dd, J = 15.6 Hz, trans H), 7.5 (t
liked due to dd, J = 7.6 Hz, ArH), 7.82 (d, J = 7.8 Hz, ArH), 8.03 (d, J = 9.0 Hz, 2ArH), 8.11
(dd, J = 15.6 Hz, trans H); 13C NMR (75 MHz, CDCl3) δ 55.4 (OCH3) 124.1 (q, JC-F = 272.3
Hz, CF3), 126.2 (q, JC-F = 5.6 Hz), 126.3, 128.0, 129.0 (q, JC-F = 30.2 Hz), 129.5, 129.6,
131.0, 132.1, 134.2 (d, JC-F = 1.5 Hz), 139.2 (d, JC-F = 1.8 Hz), 163.7 (ArC, CH), 188.3 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(3-(trifluoromethyl)phenyl)prop-2-en-1-one

(10c). Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 3-
(trifluoromethyl)benzaldehyde (1.07 mL, 8.0 mmol) in EtOH (25 mL), gave 10c as a white
solid (1.8 g, 88%); Rf = 0.20 (n-hexane/EtOAc 9/1); mp: 98.0 – 99.0 oC; 1H NMR (400 MHz,
CDCl3) δ 3.86 (s, OCH3), 6.95 (d, J = 8.84 Hz, 2ArH), 7.57 – 7.65 (m, 3ArH), 7.72 – 7.81 (m,
ArH, trans H), 7.84 (s, ArH), 8.02 (d, J = 8.8 Hz, 2ArH); 13C NMR (75 MHz, CDCl3) δ 55.5
(OCH3), 114.0, 123.5, 123.9 (q, JC-F = 270.9 Hz, CF3), 124.5 (q, JC-F = 3.7 Hz), 126.5 (q, JC-F
= 3.7 Hz), 129.5, 130.7, 130.9, 131.4 (q, JC-F = 32.3 Hz), 131.5, 135.9, 141.9, 162.7 (ArC,
CH), 188.0 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(4-(trifluoromethyl)phenyl)prop-2-en-1-one
(10d). Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 4-
(trifluoromethyl)benzldehyde (1.09 mL, 8.0 mmol) in EtOH (25 mL), gave 10d as a light
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1
yellow solid (1.4 g, 68%); Rf = 0.20 (n-hexane/EtOAc 9/1); mp: 133.5 – 135.0 C; H NMR
(400 MHz, CDCl3) δ 3.89 (s, OCH3), 6.99 (d, J = 8.8 Hz, 2ArH), 7.60 (d, J = 15.6 Hz, trans
H), 7.66 (d, J = 8.2 Hz, 2ArH), 7.73 (d, J = 8.2 Hz, 2ArH), 7.79 (d, J = 15.6 Hz, trans H),
8.04 (d, J = 8.8 Hz, 2ArH); 13C NMR (75 MHz, CDCl3) δ 55.5 (OCH3), 114.0, 123.9 (q, JC-F
= 270.5 Hz, CF3), 125.8 (q, JC-F = 3.8 Hz), 128.4, 130.5, 130.7, 130.9, 131.6 (q, JC-F = 32.3
Hz), 138.5, 141.8, 163.7 (ArC, CH), 188.1 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(2-fluorophenyl)prop-2-en-1-one (10e). Using
Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 2-fluoro benzaldehyde
(0.84 mL, 8.0 mmol) in EtOH (25mL) gave 10e as a white solid (1.32 g, 77%); Rf = 0.15 (n-
o
1
hexane/EtOAc 9/1); mp: 105.0 – 106.0 C; H NMR (300 MHz, CDCl3) δ 3.89 (s, OCH3),
6.99 (d, J = 8.97 Hz, 2ArH), 7.09 – 7.23 (m, 2ArH), 7.33 – 7.43 (m, ArH), 7.60 – 7.71 (m, Ar
H, trans H), 7.88 (d, J = 15.8 Hz, trans H), 8.06 (d, J = 8.9 Hz, 2ArH); 13C NMR (75 MHz,
DMSO-d6) δ 55.9 (OCH3), 114.5, 116.4 (d, JC-F = 11.3 Hz), 124.5 (d, JC-F = 3.8 Hz), 125.3 (d,

JC-F = 3.0 Hz), 129.5 (d, JC-F = 2.3 Hz), 130.7, 132.7 (d, JC-F = 9.0 Hz), 134.7 (d, JC-F = 4.5
Hz), 161.3 (d, JC-F = 249.8 Hz, CF), 163.8 (ArC, CH), 187.6 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(2-chlorophenyl)prop-2-en-1-one (10f). Using
Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 2-chloro benzaldehyde
(0.9 mL, 8.0 mmol) in EtOH (25mL) gave 10f as a white solid (1.52 g, 84%); Rf = 0.20 (n-
hexane/EtOAc 9/1); mp: 92.0 – 93.0 oC; 1H NMR (300 MHz, CDCl3) δ 3.89 (s, OCH3), 6.99
(d, J = 8.85 Hz, 2ArH), 7.28 – 7.36 (m, 2ArH), 7.41 – 7.55 (m, ArH, trans H), 7.71 – 7.79 (m,
ArH), 8.03 (d, J = 6.96 Hz, 2ArH), 8.16 (d, J = 15.7 Hz, trans H); 13C NMR (75 MHz, CDCl3)
δ 55.5 (OCH3), 113.9, 124.7, 127.1, 127.8, 130.3, 130.8, 130.9, 131.0, 133.5, 135.4, 140.0,
163.67 (ArC, CH), 188.5 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(2-methoxyphenyl)prop-2-en-1-one (10g).
Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 2-methoxy
benzaldehyde (0.97 mL, 8.0 mmol) in EtOH (25 mL) gave 10g as a yellow oil (1.74 g, 97%);
1
Rf = 0.10 (n-hexane/EtOAc 9/1); H NMR (300 MHz, CDCl3) δ 3.89 (s, OCH3), 3.92 (s,
OCH3), 6.93 – 7.02 (m, 4ArH), 7.34 – 7.40 (m, ArH), 7.61 – 7.66(m, ArH, trans H), 8.02 –
13
8.13 (m, 2ArH, trans H); C NMR (75 MHz, CDCl3) δ 55.4 (OCH3), 55.5 (OCH3), 111.3,
113.8, 120.7, 122.6, 124.1, 130.8, 120.7, 122.6, 124.1, 129.1, 130.8, 131.2, 131.4, 131.6,
139.4, 158.7, 163.3 (ArC, CH), 189.2 (CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(3-methoxyphenyl)prop-2-en-1-one (10h)
Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 3-
methoxybenzaldehyde (0.97 mL, 8.0 mmol) in EtOH (30 mL) gave 10h as an ivory solid (1.2
g, 66%); Rf = 0.15 (n-hexane/EtOAc 9/1); mp: 99.0 – 100.0 oC; 1H NMR (400 MHz, CDCl3)
δ 3.85 (s, OCH3), 3.88 (s, OCH3), 6.94 – 6.99 (m, 3ArH), 7.15 (s, ArH), 7.23 (d, J = 7.6 Hz,
ArH), 7.33 (t, J = 7.8 Hz, ArH), 7.51 (d, J = 15.6, trans H), 7.76 (d, J = 15.6 Hz, trans H),

13
8.03 (d, J = 8.8 Hz, 2ArH); C NMR (75 MHz, CDCl3) δ 55.3 (OCH3) 55.5 (CH3), 113.5,
113.9, 116.0, 121.0, 122.3, 129.9, 130.8, 131.1, 136.5, 143.8, 160.0, 163.5 (ArC, CH), 188.6
(s, CO).
Preparation of (E)-1-(4-methoxyphenyl)-3-(4-Methoxyphenyl)prop-2-en-1-one (10i)
Using Method A, 7a (1.00 g, 6.7 mmol), LiOH∙H2O (0.30 g, 6.7 mmol) and 4-
methoxybenzaldehyde (0.97 mL, 8.0 mmol) in EtOH (30 mL) gave 10i as an ivory solid (1.1
g, 65%); Rf = 0.10 (n-hexane/EtOAc 9/1); mp: 103.5 – 105.0 oC; 1H NMR (400 MHz, CDCl3)
δ 3.85 (s, OCH3), 3.89 (s, OCH3), 6.92 – 6.99 (m, 4ArH), 7.43 (d, J = 15.5 Hz, trans H), 7.60
(d, J = 8.6 Hz, 2ArH), 7.78 (d, J = 15.5 Hz, trans H), 8.03 (d, J = 8.8 Hz, 2ArH); 13C NMR
(75 MHz, CDCl3) δ 55.4 (OCH3) 55.5 (OCH3), 113.8, 114.4, 119.6, 127.8, 130.1, 130.7,
131.4, 143.8, 161.5, 163.3 (ArC, CH), 188.7 (CO).
Preparation of (E)-1-(4-hydroxyphenyl)-3-phenylprop-2-en-1-one (11a). Using Method A,
7d (1.00 g, 7.34 mmol), LiOH∙H2O (0.37 g, 8.81 mmol) and benzaldehyde (0.9 mL, 8.81
mmol) in EtOH (30 mL) gave 11a as a yellow solid (1.08 g, 65%); Rf = 0.20 (CH2Cl2/EtOAc
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1
20/1); mp: 109.0 – 111.5 C; H NMR (300 MHz, DMSO-d6) δ 6.89 (d, J = 8.6 Hz, 2ArH),
7.39 – 7.46 (m, 3ArH), 7.67 (d, J = 15.6 Hz, trans H), 7.84 – 7.93 (m, 2ArH), 8.07 (d, J = 8.6
13
Hz, 2ArH), 10.4 (br s, OH); C NMR (75 MHz, DMSO-d6) δ 115.8, 122.6, 129.1, 129.3,
129.6, 130.7, 131.6, 135.3, 143.1, 162.7 (ArC, CH), 187.6 (CO).
Preparation of (E)-1-(4-hydroxyphenyl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one
(11b) Using Method A, 7d (5.00 g, 36.7 mmol), LiOH∙H2O (1.85 g, 44.1 mmol) and 2-
(trifluoromethyl) benzaldehyde (7.26 mL, 55.1 mmol) in EtOH (150 mL) gave 11b as a light
yellow solid (6.54 g, 61%); Rf = 0.30 (CH2Cl2/EtOAc 20/1); mp: 194.0 ‒ 195.0 oC; 1H NMR
(400 MHz, DMSO-d6) δ 6.93 (d, J = 11.9, 2ArH), 7.77 – 7.85 (m, ArH, trans H), 7.91 – 8.03
(m, ArH, trans H), 8.11 (d, J = 8.64 Hz, 2ArH), 8.32 (d, J = 7.84 Hz, ArH), 10.5 (s, OH); 13C

NMR (75 MHz, DMSO-d6) δ 116.0, 124.6 (q, JC-F = 273.0 Hz, CF3), 126.4 (q, JC-F = 3.7 Hz),
126.7, 127.9 (q, JC-F = 29.3 Hz), 129.0, 129.2, 130.4, 131.8, 133.2, 133.6, 137.2, 163.1 (ArC,
CH), 187.2 (CO).
Preparation of (E)-1-(4-hydroxyphenyl)-3-(2-methoxyphenyl)prop-2-en-1-one (11g).
Using Method A, 7d (1.00 g, 7.34 mmol), LiOH∙H2O (0.37 g, 8.81 mmol) and 2-
methoxybenzaldehyde (1.2 g, 8.81 mmol) in EtOH (30 mL) gave 11g as a yellow solid (0.56
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g, 30%); Rf = 0.30 (CH2Cl2/EtOAc 19/1); mp: 190.0 – 192.0 C; H NMR (300 MHz,
DMSO-d6) δ 3.90 (s, OCH3), 6.90 (d, J = 8.7 Hz, 2ArH), 7.02 (t, J = 7.4 Hz, ArH), 7.11 (d, J
= 8.3 Hz, ArH), 7.43 (t, J = 7.78 Hz, ArH), 7.84 (d, J = 15.7 Hz, trans H), 7.92 – 8.05 (m,
3ArH, trans H), 10.4 (br s, OH); 13C NMR (75 MHz, DMSO-d6) δ 56.1 (OCH3), 112.2, 115.9,
121.1, 122.4, 123.6, 128.8, 129.7, 131.5,132.4, 137.8, 158.6, 162.6 (ArC, CH), 187.8 (CO).
Preparation of (E)-3-(2-(trifluoromethyl)phenyl)-N-phenyl-2-propenamide (12a). Using
Method A, 7e (500 mg, 2.31 mmol), DMTMM (703 mg, 2.54 mmol) and aniline (99.8 μL,
2.54mmol) gave 12a as a white solid (174.3 mg, 26%); Rf = 0.50 (n-hexane/EtOAc 3/2); mp:
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162.0 ‒ 163.5 C; H NMR (300MHz, DMSO-d6)  6.91 (d, J = 15.5 Hz, trans H), 7.09 ‒
13
7.91 (m, 10ArH), 10.3 (s, C(O)NH); C NMR (75 MHz, DMSO-d6)  119.3 (2ArC), 123.6
(CH), 124.1 (q, JC-F = 272.4 Hz, CF3), 126.1, 126.9 (ArC), 126.9 (q, JC-F = 29.4 Hz, CCF3),
127.8 (ArC), 128.8 (ArC), 129.7, 133.1, 133.2, 134.7 (ArC), 1389.0 (CH), 162.6 (C(O)NH).
Preparation of (E)-3-(2-chlorophenyl)-N-phenyl-2-propenamide (12b). Using Method D,
7h (500 mg, 2.48 mmol) and aniline (205 μL, 2.25mmol) gave 12b as a white solid (370.1
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mg, 58%); Rf = 0.35 (n-hexane/EtOAc 3/1); mp: 177.5 ‒ 179.0 C; H NMR (300 MHz,
DMSO-d6)  6.90 (d, J = 15.6 Hz, trans H), 7.05 ‒ 7.78 (m, 9ArH), 7.88 (d, J = 15.6 Hz,
13
trans H), 10.3 (s, NH); C NMR (75 MHz, DMSO-d6)  119.3 (CH), 123.5, 125.4, 127.7,

127.8, 130.0, 131.1, 132.5, 133.4, 135.3 (ArC), 139.1 (CH), 163.0 (C(O)NH).
Preparation of (E)-3-(2-(trifluoromethyl)phenyl)-N-(4-methoxyphenyl)-2-propenamide
(13a). Using Method A, 7e (500 mg, 2.31 mmol), DMTMM (639 mg, 2.31 mmol) and p-
anisidine (258 mg, 2.10mmol) gave 13a as a white solid (156.6 mg, 23%); Rf = 0.40
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(CH2Cl2/MeOH 99/1); mp: 177.0 ‒ 178.0 C; H NMR (300MHz, DMSO-d6)  3.73 (s,
OCH3), 6.86 (d, J = 15.3 Hz, trans H), 6.91, 6.94 (m, 2ArH), 7.62 (d, J = 15.0 Hz, trans H),
7.75 ‒ 7.89 (m, 4ArH), 10.2 (s, NH); 13C NMR (75 MHz, DMSO-d6)  55.6 (OCH3), 114.4,
121.2 (ArC), 124.9 (q, JC-F = 305.2 Hz, CF3), 126.6, 126.6 (ArC), 127.5 (q, CCF3, J = not
calculated due to overlap), 128.3, 130.1, 132.6, 133.6, 133.8 (ArC), 134.7 (CH), 156.0
(COCH3), 162.7 (C(O)NH).
Preparation of (E)-3-(2-chlorophenyl)-N-(4-methoxyphenyl)-2-propenamide (13b).
Using Method D, 7h (500 mg, 2.48 mmol), triethylamine (TEA) (475 μL, 3.38 mmol) and p-
anisidine (277 mg, 2.25mmol) gave 13b as a white solid (482.6 mg, 75%); Rf = 0.45 (n-
hexane/EtOAc 2/1); mp: 182.0 ‒ 182.5 oC; 1H NMR (300MHz, DMSO-d6)  3.73 (s, OCH3),
6.85 (d, J = 15.6 Hz, trans H), 6.90 ‒ 7.77 (m, 8ArH), 7.84 (d, J = 15.6 Hz, trans CH), 10.2 (s,
C(O)NH); 13C NMR (75 MHz, DMSO-d6)  55.2 (OCH3), 114.0, 120.8 (ArC),
125.5(C(O)CH), 127.6, 127.8, 130.0, 131.0, 132.2, 132.6, 133.4 (ArC), 134.8 (CH), 155.5
(COCH3), 162.5 (C(O)NH).
Preparation of (E)-3-(2-(trifluoromethyl)phenyl)-N-(4-hydroxyphenyl)-2-propenamide
(14a). Using Method C, 7e (1.00 g, 4.63 mmol), N-methylmorpholine (763 μL, 6.94 mmol),
Isobutylchloroformate (763 μL, 5.86 mmol) and 4-aminophenol (556 mg, 5.09mmol) gave
14a as a yellow solid (575.1 mg, 40%); Rf = 0.35 (CH2Cl2 /MeOH 19/1); mp: 228.0 ‒ 230.0
oC; 1H NMR (300MHz, DMSO-d6)  6.71 ‒ 6.75 (m, 2ArH), 6.85 (d, J = 15.3 Hz, trans H),

7.48 ‒ 7.88 (m, 7ArH), 9.27 (s, OH), 10.10 (s, NH);13C NMR (75 MHz, DMSO-d6)  115.2,
120.9 (ArC), 124.1 (q, J C-F = 266.6 Hz, CF3), 126.1 (q, J C-F = 5.7 Hz, ArC), 126.8 (q, JC-F
=
29.5 Hz, CCF3), 127.1, 127.7, 129.6, 130.6, 133.0, 133.4 (ArC), 134.0 (CH), 156.0 (COH),
162.7 (C(O)NH).
Preparation of (E)-3-(2-chlorophenyl)-N-(4-hydroxyphenyl)-2-propenamide (14b). Using
Method D, 7h (500 mg, 2.48 mmol), triethylamine (TEA) (475 μL, 3.38 mmol) and 4-
aminophenol (245 mg, 2.25mmol) gave 14b as a yellow solid (164.2 mg, 24%); Rf = 0.40 (n-
hexane/EtOAc 1/1); mp: 208.0 ‒ 210.0 oC; 1H NMR (300MHz, DMSO-d6)  6.70 ‒ 6.75 (m,
2ArH), 6.84 (d, J = 15.6 Hz, trans H), 7.41 ‒ 7.76 (m, 6ArH), 7.82 (d, J = 15.6 Hz, trans H),
13
9.26 (s, ArOH), 10.07 (s, NH); C NMR (75 MHz, DMSO-d6)  115.2, 121.0 (ArC), 125.7
(CH), 127.6, 127.8, 130.0, 131.0, 132.7, 133.3 (ArC), 133.6 (CH), 153.6 (COH), 162.4
(C(O)NH).
Preparation of (E)-3-(2-(trifluoromethyl)phenyl)-N-(3-hydroxyphenyl)-2-propenamide
(15a). Using Method C, 7e (1.00 g, 4.63 mmol), N-methylmorpholine (763 μL, 6.94 mmol),
Isobutylchloroformate (763 μL, 5.86 mmol) and 4-aminophenol (556 mg, 5.09mmol) gave
15a as a white solid (575.1 mg, 40%); Rf = 0.40 (n-hexane/EtOAc 1/1); mp: 191.0 ‒ 192.0 oC;
1H NMR (400MHz, DMSO-d6)  6.49 (m, ArH), 6.89 (d, J = 15.4 Hz, trans H), 7.06 ‒ 7.88
(m, 7ArH, trans H), 9.47 (s, COH), 10.2 (s, NH); 13C NMR (75 MHz, DMSO-d6)  106.9,
110.6, 111.3 (ArC), 124.6 (q, JC-F = 270.7 Hz, CF3), 126.6 (ArC), 127.4 (q, JC-F = 29.3 Hz,
CCF3), 127.5, 128.3, 130.0, 130.2, 133.5, 133.8, 135.1 (ArC), 140.5 (CH), 158.2 (COH),
163.0 (C(O)NH).
Preparation of (E)-3-(2-chlorophenyl)-N-(3-hydroxyphenyl)-2-propenamide (15b). Using
Method D, 7h (500 mg, 2.48 mmol), triethylamine (TEA) (475 μL, 3.38 mmol) and 4-

aminophenol (245 mg, 2.25mmol) gave 15b as a white solid (267 mg, 97%); Rf = 0.55 (n-
o
hexane/EtOAc 1/1); mp: 212.0 ‒ 214.0 C; 1H NMR (400MHz, DMSO-d6)  6.48 (m, ArH),
6.89 (d, J = 15.6 Hz, trans H), 7.06 ‒ 7.77 (m, 8ArH), 7.85 (d, J = 15.6 Hz, trans H), 9.47 (s,
OH), 10.18 (s, NH); 13C NMR (75 MHz, DMSO-d6)  106.5, 110.1, 110.78 (ArC), 125.6
(C(O)CH), 127.7, 127.8, 179.5, 130.1, 131.1, 132.6, 133.4, 135.1 (ArC), 140.1 (CH), 157.7
(COH), 162.9 (C(O)NH).
Preparation of (E)-3-(2-(trifluoromethyl)phenyl)-N-(3-fluorophenyl)-2-propenamide
(16a). Using Method C, 7e (1.00 g, 4.63 mmol), N-methylmorpholine (694 μL, 6.31 mmol),
Isobutylchloroformate (657 μL, 5.05 mmol) and 3-fluoroaniline (404 μL, 4.21 mmol) gave
16a as a white solid (990.6 mg, 76%); Rf = 0.30 (n-hexane/EtOAc 3/1); mp: 154.5 ‒ 156.0 oC;
1H NMR (400MHz, DMSO-d6)  6.88 (d, J = 15.4 Hz, trans H), 6.92 ‒ 7.91 (m, 9ArH),
13
10.57 (s, NH); C NMR (75 MHz, DMSO-d6)  106.6 (d, JC-F = 26.3 Hz), 110.6 (d, JC-F
=
20.9 Hz), 115.5 (ArC), 124.6 (q, JC-F = 272.3 Hz, CF3), 126.6 (q, JC-F = 5.5 Hz, ArC), 126.9
(ArC), 127.3 (q, JC-F = 29.4 Hz, CCF3), 130.3, 130.8, 131.0 (ArC), 133.6, 135.7, 141.1 (ArC),
162.6 (d, JC-F = 240.0 Hz, ArC-F), 163.4 (C(O)NH).
Preparation of (E)-3-(3-(trifluoromethyl)phenyl)-N-(3-fluorophenyl)-2-propenamide
(16b). Using Method C, 7f (1.00 g, 4.63 mmol), N-methylmorpholine (694 μL, 6.31 mmol),
Isobutylchloroformate (657 μL, 5.05 mmol) and 3-fluoroaniline (404 μL, 4.21 mmol) gave
16b as a white solid (538 mg, 43%); Rf = 0.35 (n-hexane/EtOAc 3/1); mp: 110.0 ‒ 111.0 oC;
1H NMR (400MHz, DMSO-d6)  6.89 ‒ 6.93 (m, 2ArH), 6.94 (d, J = 15.8 Hz, trans H), 7.38
13
‒ 8.00 (m, 7ArH, trans H), 10.5 (s, NH); C NMR (75 MHz, DMSO-d6)  106.1 (d, JC-F
=
26.1 Hz), 109.9 (d, JC-F = 21.0 Hz), 115.0, 123.8 (ArC), 123.9 (q, JC-F = 270.8 Hz, CF3),
124.0, 126.0 (ArC), 129.3 (q, JC-F = 31.6 Hz, CCF3), 130.0 (ArC), 130.3 (d, JC-F = 9.4 Hz),
131.5, 135.6, 138.9 (ArC), 140.7 (d, JC-F = 9.4 Hz), 162.1 (d, JC-F = 239.9 Hz, ArC-F), 163.4

(C(O)NH).
Preparation of (E)-3-(4-(trifluoromethyl)phenyl)-N-(3-fluorophenyl)-2-propenamide
(16c). Using Method C, 7g (250 mg, 1.15 mmol), N-methylmorpholine (171 μL, 1.56 mmol),
Isobutylchloroformate (162 μL, 1.24 mmol) and 3-fluoroaniline (101 μL, 1.04 mmol) gave
16c as a white solid (210 mg, 68%); Rf = 0.45 (n-hexane/EtOAc 3/1); mp: 152.0 ‒ 152.5 oC;
1H NMR (400MHz, DMSO-d6)  6.90 ‒ 6.94 (m, ArH), 6.95 (d, J = 15.8 Hz, trans H), 7.35 ‒
7.87 (m, 7ArH, trans H), 10.5 (s, NH); 13C NMR (75 MHz, DMSO-d6)  106.6 (d, JC-F = 26.1
Hz), 110.4 (d, JCF = 20.9 Hz), 115.5 (ArC), 124.5 (q, JC-F = 267.4 Hz, CF3), 125.1, 126.3
(ArC), 128.8 (ArC), 130.0 (q, JC-F = 31.6 Hz, CCF3), 130.9 (d, JC-F = 9.4 Hz), 139.1, 139.4,
141.3 (ArC), 162.6 (d, JC-F = 239.8 Hz, ArCF), 163.8 (C(O)NH).
Preparation of (E)-3-(4-(trifluoromethyl)phenyl)-N-(2-fluorophenyl)-2-propenamide
(17a). Using Method C, 7g (250 mg, 1.15 mmol), N-methylmorpholine (171 μL, 1.56 mmol),
Isobutylchloroformate (162 μL, 1.24 mmol) and 2-fluoroaniline (101 μL, 1.04 mmol) gave
17a as a white solid (143 mg, 45%); Rf = 0.40 (n-hexane/EtOAc 5/1); mp: 160.5 ‒ 163.0 oC;
1H NMR (400MHz, DMSO-d6)  7.14 ‒ 7.21 (m, 2ArH), 7.22 (d, J = 15.4 Hz, trans H), 7.23
13
‒ 7.32 (m, ArH), 7.68 (d, J = 15.8 Hz, trans H), 7.76 ‒ 8.15 (m, 5ArH), 10.1 (s, NH); C
NMR (75 MHz, DMSO-d6)  115.9 (d, JC-F = 19.2 Hz, 2ArC), 124.0, 124.5 (q, JC-F = 271.0
Hz, CF3), 124.8, 125.1, 125.7, 126.3, 126.7, 128.8 (ArC), 130.0 (q, JC-F = 31.6 Hz, CCF3),
139.2, 139.3 (ArC), 154.8 (d, JC-F = 243.4 Hz, ArC-F), 163.9 (C(O)NH).
Preparation of (E)-3-(4-(trifluoromethyl)phenyl)-N-(4-fluorophenyl)-2-propenamide
(18a). Using Method C, 7g (250 mg, 1.15 mmol), N-methylmorpholine (171 μL, 1.56 mmol),
Isobutylchloroformate (162 μL, 1.24 mmol) and 4-fluoroaniline (101 μL, 1.04 mmol) gave