Synthesis of novel cinnamoyl amides using a solvent-free microwave-assisted method

Article abstract of DOI:10.1080/00397911.2011.604148

A novel series of potential biologically active new cinnamoyl amides were synthesized in good yield and short reaction times. We have studied the one-pot, solvent-free reaction of cinnamic acid derivatives with aromatic amines using 1,3-dicyclohexylcarbodiimide under microwave irradiation in the presence of small quantities of dimethylformamide to improve energy transfer.

Full text of DOI:10.1080/00397911.2011.604148

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Synthesis of Novel Cinnamoyl Amides
Using a Solvent-Free Microwave-Assisted
Method
Dr. Rolando F. Pellón a & Maite L. Docampo a
a Laboratorio de Síntesis Orgánica, Facultad de Química, Universidad
de La Habana, Ciudad de la Habana, Cuba
Accepted author version posted online: 10 May 2012.Version of
record first published: 08 Nov 2012.
To cite this article: Dr. Rolando F. Pellón & Maite L. Docampo (2013): Synthesis of Novel Cinnamoyl
Amides Using a Solvent-Free Microwave-Assisted Method, Synthetic Communications: An International
Journal for Rapid Communication of Synthetic Organic Chemistry, 43:4, 537-552
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Synthetic Communications1, 43: 537–552, 2013
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2011.604148
SYNTHESIS OF NOVEL CINNAMOYL AMIDES USING A
SOLVENT-FREE MICROWAVE-ASSISTED METHOD
´
Rolando F. Pellon and Maite L. Docampo
Laboratorio de Sıntesis Organica, Facultad de Quımica,
´
´
´
Universidad de La Habana, Ciudad de la Habana, Cuba
GRAPHICAL ABSTRACT
Abstract A novel series of potential biologically active new cinnamoyl amides were
synthesized in good yield and short reaction times. We have studied the one-pot, solvent-free
reaction of cinnamic acid derivatives with aromatic amines using 1,3-dicyclohexylcarbo-
diimide under microwave irradiation in the presence of small quantities of dimethylforma-
mide to improve energy transfer.
Keywords Cinnamoyl amides; condensation; microwave heating; solvent-free reaction;
synthetic methods
INTRODUCTION
Cinnamic acid and its derivatives are important reagents in organic synthesis as
intermediates and final products. Various cinnamic acid derivatives have been stud-
ied as cancer-preventive agents[1] and antimalaric agents.[2] Also, inhibitory effects
on melanin biosynthesis in skin were demostrated.[3] Cinnamoyl amides are potential
hypoglycemic agents[4] and were evaluated as anti-inflamatory and analgesic activi-
ties.[5] Several of these compounds were obtained and showed an improvement in
anti-Chagas activity in comparison to the earlier derivatives.[6] The best activity
was obtained with an ethyl, ethenyl, and thiomethyl or a hydrogen bond acceptor
as a nitro group in the para-position of the terminal phenyl residue.[7] The
growing interest during recent years in natural and synthetic amides of cinnamic acid
Received June 16, 2011.
Address correspondence to Dr. Rolando F. Pellon, Laboratorio de Sıntesis Organica, Facultad de
´
Quımica, Universidad de La Habana. Calle Zapata y Ave. de los Presidentes s=n Vedado, Plaza de la
´
´
´
Revolucion, Ciudad de la Habana, CP 10400, Cuba. E-mail: pellon@fq.uh.cu
´
537

´
R. F. PELLON AND M. L. DOCAMPO
538
is due to the metabolical stability of the amide group in comparison to that of
the ester group.[8]
A conventional synthesis of amide compounds has been performed by a con-
densation between carboxylic acid and amine with heating.[9] Cinnamoyl amides
can be obtained via acyl chlorides, which were prepared by the action of thionyl
chloride on cinnamic acids and reacted in situ with the corresponding amine in
chloroform as solvent.[10] Yesilada and Zurlo[5] reported the synthesis of cinnamoyl
tertiary amides using 1,3-dicyclohexylcarbodiimide=4-hydroxybenzotriazol in
dimethylformamide (DMF) as solvent at room temperature. However, these syn-
thetic routes often involve long reaction times, toxic reactives or solvents, and
labor-intensive operations.
On the other hand, Nomura et al.[11] tried to prepare the amide compounds of
cinnamic acids with alkylamines by microwave (MW) irradiation. However, the styr-
enes (descarboxilation reaction) were obtained predominantly from a cinnamoyl
amide–forming reaction.
Previous work[12] of our group has demonstrated that MW or ultrasound
irradiation gives significant rate enhancements and improved yields in organic reac-
tions. Many reactions that typically need many hours to reach completion with con-
ventional heating can be brought to full conversion in only seconds or minutes by
utilizing these powerful tools.[13]
To overcome these disadvantages in the amide-forming reaction, in this work
we describe a facile one-pot condensation reaction of cinnamic acid and aromatic
amines under solvent-free conditions using MW irradiation to obtain new cinnamoyl
amide derivatives.
RESULTS AND DISCUSSION
As a first part of this work we studied the condensation of cinnamic acid deri-
vatives with aromatic amines under MW irradiation in absence of solvent (Scheme 1).
In our initial screening experiments, we chose the condensation of cinnamic acid (1a)
with 2-aminothiazole (2a) as the model for exploring suitable reaction conditions.
The synthetic route is shown in Scheme 1.
Before performing any new reaction under MW irradiation, we needed to test
the thermal behavior of every reactive as well as reaction mixtures when they are
submitted to the electromagnetic field. This preliminary step allowed determination
of adequate conditions of incident power and irradiation time. No degradation of
reactants and products was obtained under MW irradiation at 180 W and 10 min,
which are, respectively, the greatest irradiation power and longest time used in the
experiments.
We examined the condensation of equimolecular amounts of cinnamic acid
and 2-aminothiazole with microwave heating at 180 W for 10 min (Table 1 entry
1), but the condensation did not take place satisfactorily, obtaining only 12% yield
of the corresponding cinnamoyl amide.
To ensure the reaction to go to completion we decided to use a coupling
dehydrating agent such as 1,3-dicyclohexyl-carbodiimide (DDC), which is converted
in the process to dicyclohexylurea. Using a relationship of 1:1:2 (cinnamic

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
539
Scheme 1. Condensation of cinnamic acid derivatives with aromatic amines under microwave irradiation
in the absence of solvent.
acid–amine–DCC) and the MW activation conditions described previously, we
obtained 43% yield of cinnamoyl amide (Table 1, entry 2).
With the aim of enhancing yield, we examined this reaction in wet conditions
using a small amount of DMF, and cinnamoyl amide (3a) was obtained in 90% yield
(Table 1, entry 3). This polar molecule (i.e., highly sensitive to MW irradiation) was
Table 1. MW-assisted solvent-free condensation reaction of cinnamic acid (1a) and 2-aminothiazole (2a):
optimization conditionsa
Entry
Molar ratiob
DMF
Yield (%)c
Standard deviation (S)
1
2
3
4
5
6
7
8
1:1:0
1:1:2
None
None
12
43
90
91
89
90
92
79
ꢀ1.5
ꢀ2.0
ꢀ1.7
ꢀ2.2
ꢀ1.3
ꢀ1.6
ꢀ1.4
ꢀ1.7
1:1:2
Drops
Drops
Drops
Drops
Drops
Drops
1:1:1.5
1:1:1.2
1:1:1.1
1:1:1. 0
1:1:0.5
aMW conditions: P ¼ 180 W, reaction time: 10 min.
bCinnamic acid–amine–DCC.
cIsolated yields.

´
R. F. PELLON AND M. L. DOCAMPO
540
Figure 1. Profile of rise in temperature for the MW-assisted solvent-free synthesis of 3a. Without DMF
(1); adding drops of DMF (2) (20 mmol of 1a–20 mmol of 2a–40 mmol of DCC); performed at 180 W
full time.
added to improve the energy transfer and to allow higher temperatures.[14] To attri-
bute these effects, the profiles of temperature increases were carefully studied.
The employment in this investigation of a modern MW reactor (Synthewave
S402) for organic synthesis permitted controlled reaction conditions such as tem-
perature and pressure. We used this reactor to monitor the temperature profiles dur-
ing the condensation of cinnamic acid and 2-aminothiazole in presence of DCC
under MW irradiation at 180 W from 0 to 10 min reaction time (with and without
DMF), and the results are shown in Fig. 1.
The maximum temperature is in the range of 59–61 ꢁC when DMF was not
present, obtaining a poor yield (43%) of compound 3a. Further, upon the addition
of DMF, the reaction mixture was rapidly heated, reaching a range of 131–137 ꢁC
after 3 min of exposure to MW, obtaining 90% yield.
Next, we investigated the effect of relative amounts of DCC in the presence of
DMF. The main results are summarized in Table 1 (entries 3–8). The reaction under
MW conditions was obtained successfully using a ratio of cinnamic acid–amine–
DCC 1:1:1 in the presence of small amounts of DMF (Table 1, entry 7).
Figure 2. Effect of the irradiation power in the condensation reaction of cinnamic acid 1a (20 mmol) with
2-aminothiazole 2a (20 mmol) in presence of DCC (20 mmol) and drops of DMF.

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
541
Table 2. Comparison between microwave (MW) irradiation and conventional heating for the synthesis of
new cinnamoyl amidesa
Entry
Substituents
Method T (ꢁC)b,c t (min) Yield (%)d
3a
3b
R1 ¼ R2 ¼ R3 ¼ R4 ¼ H
MW
D
MW
D
135
135
135
135
3
360
2
94
8
R1 ¼ R4 ¼ H; R2 ¼ R3 ¼ OCH3
96
12
300
3c
3d
R1 ¼ R4 ¼ R5 ¼ H; R2 ¼ R3 ¼ OCH3
MW
D
MW
D
140
140
140
140
1
300
1
97
14
95
18
R1 ¼ R4 ¼ H; R2 ¼ R3 ¼ OCH3; R5 ¼ CH3
300
3e
3f
R1 ¼ R2 ¼ R3 ¼ R4 ¼ R6 ¼ R7 ¼ H
MW
D
MW
D
MW
D
MW
D
MW
D
MW
D
MW
D
MW
D
135
135
135
135
135
135
135
135
135
135
140
140
140
140
130
130
130
130
135
135
3
360
2
90
6
R1 ¼ R4 ¼ R6 ¼ R7 ¼ H; R2 ¼ R3 ¼ OCH3
R1 ¼ R3 ¼ R6 ¼ R7 ¼ H; R2 ¼ R4 ¼ OCH3
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ OCH3
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ OC2H5
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ OC3H7
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ OC4H9
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ CH3
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ C2H5
R2 ¼ R3 ¼ R4 ¼ R6 ¼ R7 ¼ H; R1 ¼ Cl
93
7
300
2
3g
3h
3i
92
8
300
2
90
6
300
2
92
5
300
2
3j
91
5
300
2
3k
3l
92
7
300
3
89
4
360
3
3m
3n
MW
D
MW
D
90
5
360
2
91
9
300
(Continued )

´
R. F. PELLON AND M. L. DOCAMPO
542
Table 2. Continued
Entry
3o
Substituents
Method T (ꢁC)b,c t (min) Yield (%)d
R1 ¼ R2 ¼ R4 ¼ R6 ¼ R7 ¼ H; R3 ¼ Cl
MW
D
135
135
140
140
140
140
135
135
140
140
140
140
135
135
135
135
2
300
2
90
8
3p
R1 ¼ R4 ¼ R7 ¼ H; R2 ¼ R3 ¼ R6 ¼ OCH3
R1 ¼ R4 ¼ R7 ¼ H; R2 ¼ R3 ¼ OCH3; R6 ¼ OC2H5
R1 ¼ R4 ¼ R7 ¼ H; R2 ¼ R3 ¼ OCH3; R6 ¼ CH3
MW
D
MW
D
MW
D
93
10
91
9
300
2
3q
300
2
3r
89
9
300
2
3s
R1 ¼ R4 ¼ R7 ¼ H; R2 ¼ R3 ¼ OCH3; R6 ¼ SO2CH3 MW
90
5
D
MW
D
MW
D
MW
D
300
2
3t
R1 ¼ R4 ¼ R7 ¼ H; R2 ¼ R3 ¼ OCH3; R6 ¼ NO2
R1 ¼ R4 ¼ R6 ¼ H; R2 ¼ R3 ¼ OCH3; R7 ¼ Cl
R1 ¼ R4 ¼ R6 ¼ H; R2 ¼ R3 ¼ OCH3; R7 ¼ CH3
93
11
88
3
300
3
3u
360
3
3v
89
4
360
3w
3x
R1 ¼ R2 ¼ R3 ¼ R4 ¼ R8 ¼ H
MW
D
MW
D
145
145
140
140
1
300
98
12
97
10
R1 ¼ R2 ¼ R3 ¼ R4 ¼ H; R8 ¼ COOH
1.5
300
aReaction conditions: cinnamic acid (20 mmol), amine (20 mmol), DCC (20 mmol), DMF (3 drops),
120 W.
bMethod MW: The temperature was controlled throughout the reaction and evaluated by infrared
detector, which indicated the surface temperature after calibration with an optical fibre.
cMethod D: The temperature was controlled using a digital thermometer inside the reaction mixture.
dYields (%) refer to those of pure isolated products properly characterized by spectroscopic data (1H,
13C NMR, MS).
Finally, we performed several experiments at various powers to study the effect
of irradiation time on yields of cinnamoyl amide 3a under the conditions studied
previously. The best results (94% yield) were obtained within 3 min at a power of
120 W (Fig. 2).
With the optimized procedure in hand, the scope of this condensation was
further explored with different cinnamic acid and amines (thiazolamines, benzothia-
zolamines, aminopyridines, aminobenzoic acids, and anilines), and the results are
summarized in Table 2. In general, no significant difference of the reactivity was
observed for the examined reactants (cinnamic acid and amines) with varied
electronic properties, electron-rich and electron-poor; the rates and yields of the
reactions were comparable (Table 2).
To show the advantages of the MW heating mode, Table 2 shows results for
the synthesis of new cinnamoyl amides compared to classic heating. To check the

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
543
possibility of intervention of specific nonpurely thermal effects of microwaves, they
are also compared to solvent-free reaction by classical heating (thermostated oil
bath) in the same conditions as under microwave (time, temperature, profiles of rise
in temperature, vessels). The lower yields obtained with conventional heating mode,
even after 6 h of reaction, indicate once more that the effect of MW irradiation is not
purely thermal (Table 2).
We suggest that the improvement achieved with this method, due to a strong
specific MW effect, could be connected to the reaction mechanism and evolution
of polarity during the course of the reaction.
CONCLUSIONS
A novel series of potentially biologically active cinnamoyl amides was synthe-
sized using the MW-assisted procedure described here. This procedure leads to good
yields, in the absence of solvent, within very short reaction times and with simplified
and safe workup.
EXPERIMENTAL
Reactions were monitored by thin-layer chromatography (TLC) on Merck
60 F254 (0.25-mm) plates, which were visualized using a CAMAG UV-Cabinet II
at 254 nm using chloroform–ethyl acetate (4:1 v=v). Melting points were determi-
nated in open capillaries with a Gallenkanmp melting-point apparatus and are
1
uncorrected. H and 13C NMR spectra were recorded on a Bruker Avance 300
1
instrument at 298 K, using CDCl3 as solvent unless otherwise stated. The H and
13C chemical shifts are reported in parts per million (ppm) relative to residual deut-
erated solvent signal as an internal reference. The coupling constants (J) are given in
hertz (Hz). Mass spectra were recorded by using Spectrometer Q-TOFII-Micromass,
Manchester Ing. Elemental analyses were carried out on a Fisons EA 1108 CHNS-O
apparatus at the Microanalytical Unit. All reagents purchased from commercial
sources were used without further purification. All experiments were replicated to
ensure the reproducibility, and the yields reported are averages of at least three
independent runs.
Microwave Irradiation Experiments
All MW irradiation experiments were carried out in a MW reactor monomode
system (Synthewave 402: prototype designed by Prolabo). The temperature is con-
trolled by an infrared (IR) detector, which indicates the surface temperature. (IR
measurment was calibrated using a thermocouple introduced in the reaction mix-
ture.) Mechanical stirring provides good homogeneity of the materials. Automatic
control of the irradiation (power and temperature) and data treatment were followed
by a computer system. All the reactions were performed in a cylindrical Pyrex vessel.
For the sake of comparison, reactions were conducted under classical heating
in a thermostated oil bath. Measurements of the temperature evolution were made in
the reaction medium with a digital thermometer.

´
R. F. PELLON AND M. L. DOCAMPO
544
Condensation of Cinnamic Acids (1a–1k) with Amines (2a–2m)
Under Microwave Irradiation
Cinnamic acid derivative (20 mmol), amine (20 mmol), DCC (20 mmol), and
DMF (three drops) were placed in a MW monomode reactor in a cylindrical Pyrex
vessel. The mixture was irradiated at 120 W with controlled temperatures for reac-
tion times as indicated in Table 2. Continuous mechanical stirring provided a good
homogeneity of materials. When the irradiation was stopped, the reaction mixture
was treated with dichloromethane (CH2Cl2) and the precipitated DHU was filtered
off. The organic layer was concentrated in vacuum, and the crude products were
crystallized from methanol to give the pure products 3a–3x in 88–98% yields.
The structures of the products obtained were confirmed by melting point,
1
elemental analyses, H NMR, 13C NMR, and mass spectra.
(2E)-3-Phenyl-N-1,3-thiazol-2-ylacrylamide (Table 2, 3a)
1
The mixture was irradiated for 3 min. Yield: 94%. Mp 202–203 ꢁC. H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.68 (d, 1H, Hb, J ¼ 15.8 Hz), 7.21 (d, 1H,
Ar, H4’), 7.27–7.30 (m, 1H, Ar, H4), 7.43 (dd, 2H, Ar, H3, H5), 7.51 (d, 1H, Ar,
3
H5’), 7.59 (dd, 2H, Ar, H2, H6), 7.77 (d, 1H, Ha, J ¼ 15.8 Hz), 12.10 (s, 1H, NH).
13C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C-40: 111.8; C-b: 117.3; C-2, C-6:
128.2; C-3, C-5: 129.2; C-4: 130.2; C-1: 134.9; C-50: 138.5; C-a: 141.9; C-20: 153.9;
þ
=
C(C O): 164.3. ESI-MS (m=z): 231.2759 [M þ H] . Anal. calcd. for C12H10N2OS
(230.29): C, 62.59; H, 4.38. Found: C, 62.57; H, 4.39.
(2E)-3-(3,4-Dimethoxyphenyl)-N-1,3-thiazol-2-ylacrylamide
(Table 2, 3b)
1
The mixture was irradiated for 2 min. Yield: 96%. Mp 208–209ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.79, 3.82 (s, 3H, OCH3), 6.71 (d, 1H, Hb,
3J ¼ 15.7 Hz), 6.90 (d, 1H, Ar, H5), 7.11 (dd, 1H, Ar, H6), 7.22 (d, 1H, Ar, H4’), 7.25
3
(d, 1H, Ar, H2), 7.53 (d, 1H, Ar, H5’), 7.70 (d, 1H, Ha, J ¼ 15.7Hz), 12.20 (s, 1H,
NH). 13C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH3): 55.9; 55.8; C-2: 110.8;
C-40: 112.9; C-5: 113.6; C-b: 118.2; C-6: 123.1; C-1: 127.1; C-50: 137.8; C-a: 142.þ3;
0
=
C-3: 148.9; C-4: 150.8; C-2 : 154.1; C(C O): 163.4. ESI-MS (m=z): 291.3405 [M þ H] .
Anal. calcd. for C14H14N2O3S (290.34): C, 57.92; H, 4.86. Found: C, 57.91; H, 4.88.
(2E)-3-(3,4-Dimethoxyphenyl)-N-pyridin-2-ylacrylamide (Table 2, 3c)
1
The mixture was irradiated for 1 min. Yield: 97%. Mp 153–155 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.80, 3.84 (s, 3H, OCH3), 6.69 (d, 1H, Hb,
3J ¼ 15.9 Hz), 6.92 (d, 1H, Ar, H5), 7.15 (dd, 1H, Ar, H6), 7.21 (d, 1H, Ar, H2),
3
7.30 (ddd, 1H, Ar, H5’), 7.65 (d, 1H, Ha, J ¼ 15.9 Hz), 7.75 (dd, 1H, Ar, H4’),
8.19 (dd, 1H, Ar, H3’), 8.54 (dd, 1H, Ar, H6’), 12.10 (s, 1H, NH). 13C NMR
(75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH3): 55.9; 56.0; C-2: 110.2; C-5: 112.0;
C-30: 114.4; C-b: 118.3; C-50:122.9; C-6: 124.2;. C-1: 127.6; C-40: 139.2; C-a: 140.9;
0
0
=
C-3: 149.1; C-6 : 149.8; C-4: 151.3; C-2 : 152.5; C(C O): 168.7. ESI-MS

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
545
(m=z): 285.3109 [M þ H]þ. Anal. calcd. for C16H16N2O3 (284.31): C, 67.59; H, 5.67.
Found: C, 67.62; H, 5.66.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(6-methylpyridin-2-yl)acrylamide
(Table 2, 3d)
1
The mixture was irradiated for 1 min. Yield: 95%. Mp 158–160 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 2.46 (s, 3H, CH3), 3.81, 3.83 (s, 3H, OCH3),
3
6.67 (d, 1H, Hb, J ¼ 16.1 Hz), 6.90 (dd, 1H, Ar, H5’), 7.07 (d, 1H, Ar, H5), 7.14 (dd,
3
1H, Ar, H6), 7.23 (d, 1H, Ar, H2), 7.63 (d, 1H, Ha, J ¼ 16.1 Hz), 7.67 (dd, 1H, Ar,
H4’), 8.16 (dd, 1H, Ar, H3’), 11.90 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d
ppm, 25 ꢁC): C(CH3): 23.1; C(OCH3): 56.2, 56.4; C-2: 109.8; C-5: 111.4; C-30: 117.9;
C-b: 118.8; C-50:123.4; C-6: 124.2; C-1: 127.9; C-40: 137.2; C-a: 139.9; C-3: 149.þ2;
0
0
=
C-4: 151.9; C-6 : 155.2; C-2 : 156.5; C(C O): 168.1. ESI-MS (m=z): 299.3411 [M þ H] .
Anal. calcd. for C17H18N2O3 (298.34): C, 68.44; H, 6.08. Found: C, 68.40; H, 6.11.
(2E)-N-1,3-Benzothiazol-2-yl-3-phenylacrylamide (Table 2, 3e)
1
The mixture was irradiated for 3 min. Yield: 90%. Mp 246–247 ꢁC. H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.81 (d, 1H, Hb, J ¼ 16.0 Hz), 7.25–7.30 (m,
1H, Ar, H4), 7.35 (ddd, 1H, Ar, H6’), 7.40 (ddd, 1H, Ar, H7’), 7.45 (dd, 2H, Ar,
3
H3, H5), 7.63 (dd, 2H, Ar, H2, H6), 7.78 (d, 1H, Ha, J ¼ 16.0 Hz), 7.80–7.88 (m,
2H, Ar, H5’, H8’), 12.00 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d ppm,
25 ꢁC): C-b: 118.4; C-80: 119.1; C-50: 120.5; C-60: 121.0; C-70: 123.7; C-3, C-5:
128.1; C-2, C-6: 129.1; C-4: 130.0; C-40: 131.6; C-1: 134.1;. C-a:þ143.1; C-20: 148.6;
0
=
C-9 : 158.0; C(C O): 164.0. ESI-MS (m=z): 281.3443 [M þ H] . Anal. calcd. for
C16H12N2OS (280.34): C, 68.55; H, 4.31. Found: C, 68.51; H, 4.39.
(2E)-N-1,3-Benzothiazol-2-yl-3-(3,4-dimethoxyphenyl)acrylamide
(Table 2, 3f)
The mixture was irradiated 2 min. Yield: 93%. Mp 215–217 ꢁC. 1H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.81, 3.82 (s, 3H, OCH3), 6.79 (d, 1H, Hb,
3J ¼ 16.2 Hz), 6.89 (d, 1H, Ar, H5), 7.10 (dd, 1H, Ar, H6), 7.28 (d, 1H, Ar, H2),
3
7.35 (ddd, 1H, Ar, H6’), 7.41 (ddd, 1H, Ar, H7’), 7.82 (d, 1H, Ha, J ¼ 16.2 Hz),
7.88 (dd, 1H, Ar, H8’), 8.00 (dd, 1H, Ar, H5’), 12.10 (s, 1H, NH). 13C NMR
(75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH3): 55.5, 55.4; C-2: 110.9; C-5: 112.2;
C-b0: 117.9; C-80: 118.8; C-500:120.9; C-60: 121.3; C-70: 124.1; C-6: 0124.7; C-1: 129.0;
=
C-4 : 131.5; C-a: 142.8; C-2 : 148.5; C-3: 148.9; C-4: 151.0; C-9 : 157.9; C(C O):
164.2. ESI-MS (m=z): 341.4021 [M þ H]þ. Anal. calcd. for C18H16N2O3S (340.40):
C, 63.51; H, 4.74. Found: C, 63.55; H, 4.70.
(2E)-N-1,3-Benzothiazol-2-yl-3-(2,5-dimethoxyphenyl)acrylamide
(Table 2, 3g)
1
The mixture was irradiated for 2 min. Yield: 92%. Mp 173–174 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.77, 3.86 (s, 3H, OCH3), 6.92 (d, 1H, Hb,

´
R. F. PELLON AND M. L. DOCAMPO
546
3J ¼ 15.7 Hz), 7.07 (dd, 1H, Ar, H4), 7.12 (d, 1H, Ar, H3), 7.18 (d, 1H, Ar, H6), 7.31
3
0
(dt, 1H, Ar, H6’), 7.44 (dt, 1H, Ar, H7 ), 7.76 (d, 1H, Ha, J ¼ 15.7 Hz), 7.91 (dd, 1H,
Ar, H8’), 7.99 (dd, 1H, Ar, H5’), 12.40 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d
ppm, 25 ꢁC): C(OCH3): 55.4, 56.0; C-3: 113.3; C-b: 117.1; C-6: 117.9; C-80: 118.8;
C-4: 120.2; C-50:121.0; C-60: 121.4; C-70: 124.5; C-1: 126.2; C-40: 131.5; C-a: 139.9;
0
0
=
C-2 : 148.5; C-2: 153.0; C-5: 152.4; C-9 : 157.9; C(C O): 164.3. ESI-MS (m=z):
341.4003 [M þ H]þ. Anal. calcd. for C18H16N2O3S (340.40): C, 63.51; H, 4.74.
Found: C, 63.52; H, 4.71.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-methoxyphenyl)acrylamide
(Table 2, 3h)
The mixture was irradiated 2 min. Yield: 90%. Mp 221–222 ꢁC. 1H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.82 (s, 3H, OCH3), 6.82 (d, 1H, Hb,
3J ¼ 16.1 Hz), 7.04 (d, 2H, Ar, H3, H5), 7.31 (dt, 1H, Ar, H6’), 7.44 (dt, 1H, Ar,
3
0
H7 ), 7.62 (d, 2H, Ar, H2, H6), 7.75 (d, 1H, Ha, J ¼ 16.1 Hz), 7.87 (dd, 1H, Ar,
H8’), 798 (dd, 1H, Ar, H5’), 12.45 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d
ppm, 25 ꢁC): C(OCH3): 55.2; C-3, C-5: 114.4; C-b: 117.6; C-80: 119.6; C-50: 120.2;
C-60: 121.1; C-70: 124.2; C-1: 126.7; C-2, C-6: 129.7; C-40: 131.5; C-a: 142.7; C-20:
þ
0
=
148.5; C-9 : 158.0; C-4: 161.1; C(C O): 164.1. ESI-MS (m=z): 311.3725 [M þ H] .
Anal. calcd. for C17H14N2O2S (310.37): C, 65.79; H, 4.55. Found: C, 65.83; H, 4.49.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-ethoxyphenyl)acrylamide
(Table 2, 3i)
The mixture was irradiated 2 min. Yield: 92%. Mp 229–230 ꢁC. 1H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 1.35 (t, 3H, OCH2CH3), 4.10 (q, 2H,
3
OCH2CH3), 6.81 (d, 1H, Hb, J ¼ 15.8 Hz), 7.06 (d, 2H, Ar, H3, H5), 7.30 (dt, 1H,
0
Ar, H6’), 7.42 (ddd, 1H, Ar, H7 ), 7.60 (d, 2H, Ar, H2, H6), 7.74 (d, 1H, Ha,
3J ¼ 15.8 Hz), 7.86 (dd, 1H, Ar, H8’), 7.98 (dd, 1H, Ar, H5’), 12.39 (s, 1H, NH).
13C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH2CH3): 14.3; C(OCH2CH3):
63.2;. C-5: 114.9; C-b: 117.2; C-80: 119.8; C-50:120.7; C-60: 121.4; C-70: 123.8; C-1:
126.5; C-2, C-6: 129.9; C-40: 131.3; C-a: 142.7; C-þ20: 148.6; C-90: 159.0; C-4: 160.3;
=
C(C O): 164.5. ESI-MS (m=z): 325.3999 [M þ H] . Anal. calcd. for C18H16N2O2S
(324.40): C, 66.64; H, 4.97. Found: C, 66.79; H, 4.86.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-propoxyphenyl)acrylamide
(Table 2, 3j)
1
The mixture was irradiated for 2 min. Yield: 91%. Mp 218–220 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 0.99 (t, 3H, OCH2CH2CH3), 1.75 (m, 2H,
3
OCH2CH2CH3), 4.00 (t, 2H, OCH2CH2CH3), 6.81 (d, 1H, Hb, J ¼ 16.1 Hz), 7.02
0
(d, 2H, Ar, H3, H5), 7.32 (dt, 1H, Ar, H6’), 7.43 (dt, 1H, Ar, H7 ); 7.60 (d, 2H,
3
Ar, H2, H6), 7.74 (d, 1H, Ha, J ¼ 16.1 Hz), 7.85 (dd, 1H, Ar, H8’), 7.97 (dd, 1H,
13
Ar, H5’), 12.35 (s, 1H, NH). C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC):
C(OCH2CH2CH3): 10.1; C(OCH2CH2CH3): 21.8; C(OCH2CH2CH3): 69.0; C-5:
114.9; C-b: 117.5; C-80: 119.1; C-50: 120.4; C-60: 121.2; C-70: 124.1; C-1: 126.5; C-2,

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
547
0
0
0
=
C-6: 129.7; C-4 : 131.5; C-a: 142.8; C-2 : 148.8; C-9 : 158.2; C-4: 160.5; C(C O):
164.9. ESI-MS (m=z): 339.4231 [M þ H]þ. Anal. calcd. for C19H18N2O2S (338.42):
C, 67.43; H, 5.36. Found: C, 67.52; H, 5.44.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-butoxyphenyl)acrylamide
(Table 2, 3k)
1
The mixture was irradiated for 2 min. Yield: 92%. Mp 196–197 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 0.94 (m, 3H, OCH2CH2CH2CH3), 1.44 (m,
2H, OCH2CH2CH2CH3), 1.72 (m, 2H, OCH2CH2CH2CH3), 4.03 (t, 2H,
3
OCH2CH2CH2CH3), 6.80 (d, 1H, Hb, J ¼ 16.0 Hz), 7.05 (d, 2H, Ar, H3, H5), 7.33
0
(dt, 1H, Ar, H6’), 7.45 (ddd, 1H, Ar, H7 ), 7.61 (d, 2H, Ar, H2, H6), 7.75 (d, 1H,
3
Ha, J ¼ 16.0 Hz), 7.84 (dd, 1H, Ar, H8’), 7.99 (dd, 1H, Ar, H5’), 12.40 (s, 1H,
13
NH). C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH2CH2CH2CH3): 13.8;
C(OCH2CH2CH2CH3): 18.8; C(OCH2CH2CH2CH3): 30.8; C(OCH2CH2CH2CH3):
67.6; C-5: 115.2; C-b: 117.8; C-80: 119.4; C-50:120.6; C-60: 121.5; C-70: 123.9; C-1:
126.1; C-2, C-6: 130.0; C-40: 131.8; C-a: 143.1; C-þ20: 148.9; C-90: 158.3; C-4: 160.9;
=
C(C O): 164.5. ESI-MS (m=z): 353.4532 [M þ H] . Anal. calcd. for C20H20N2O2S
(352.45): C, 68.16; H, 5.72. Found: C, 67.98; H, 5.88.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-methylphenyl)acrylamide
(Table 2, 3l)
The mixture was irradiated 3 min. Yield: 89%. Mp 241–242 ꢁC. 1H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 2.35 (CH3), 6.87 (d, 1H, Hb, J ¼ 16.2 Hz),
0
7.29 (d, 2H, Ar, H3, H5), 7.34 (dt,1H, Ar, H6’), 7.42 (ddd, 1H, Ar, H7 ), 7.53 (d,
2H, Ar, H2, H6), 7.79 (d, 1H, Ha, 3J ¼ 16.2 Hz), 7.89 (dd, 1H, Ar, H8’), 7.95
(dd,1H, Ar, H5’), 12.50 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d ppm,
25 ꢁC): C(CH3): 20.8; C-b: 118.1; C-80: 119.3; C-50: 120.5; C-60: 121.3; C-70: 123.8;
C-2, C-6: 128.1; C-3, C-5: 128.9; C-40: 131.9; C-1: 138.1; C-a: 142.3; C-4: 147.8;
þ
0
0
=
C-2 : 148.8; C-9 : 157.5; C(C O): 163.9. ESI-MS (m=z): 295.3704 [M þ H] . Anal.
calcd. for C17H14N2OS (294.37): C, 69.36; H, 4.79. Found: C, 69.40; H, 4.72.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-ethylphenyl)acrylamide
(Table 2, 3m)
1
The mixture was irradiated for 3 min. Yield: 90%. Mp 166–167 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 1.20 (t, 2H, CH2CH3), 3.25 (q, 2H, CH2CH3),
3
6.92 (d, 1H, Hb, J ¼ 16.3 Hz), 7.26 (d, 2H, Ar, H3, H5), 7.35 (dt,1H, Ar, H6’), 7.44
3
0
(ddd, 1H, Ar, H7 ), 7.58 (d, 2H, Ar, H2, H6), 7.78 (d,1H, Ha, J ¼ 16.3 Hz), 7.85
(dd,1H, Ar, H8’), 7.99 (dd, 1H, Ar, H5’), 12.48 (s, 1H, NH). 13C NMR
(75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(CH2CH3): 15.0; C(CH2CH3): 27.9; C-b:
118.3; C-80: 119.7; C-50: 120.8; C-60: 121.0; C-70: 124.2; C-2, C-6: 128.0; C-3, C-5:
128.3; C-40: 131.6; C-1: 138.8; C-a: 142.9; C-4: 146.1; C-20: 148.3; C-90: 157.9;
C(C O): 163.4. ESI-MS (m=z): 309.4015 [M þ H] . Anal. calcd. for C18H16N2OS
þ
=
(308.40): C, 70.10; H, 5.23. Found: C, 70.27; H, 5.11.

´
R. F. PELLON AND M. L. DOCAMPO
548
(2E)-N-1,3-Benzothiazol-2-yl-3-(2-chlorophenyl)acrylamide
(Table 2, 3n)
1
The mixture was irradiated for 2 min. Yield: 91%. Mp 235–237 ꢁC. H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.74 (d, 1H, Hb, J ¼ 15.9 Hz), 7.17 (ddd, 1H,
0
Ar, H4), 7.29 (ddd, 1H, Ar, H6’), 7.34 (ddd, 1H, Ar, H5), 7.41 (ddd, 1H, Ar, H7 ),
3
7.51 (dd, 1H, Ar, H6), 7.70 (d, 1H, Ha, J ¼ 15.9 Hz), 7.75 (dd, 1H, Ar, H3), 7.80
(dd, 1H, Ar, H8’), 7.91 (dd, 1H, Ar, H5’), 12.47 (s, 1H, NH). 13C NMR
(75.03 MHz, DCCl3, d ppm, 25 ꢁC): C-b: 117.9; C-80: 119.0; C-50: 120.3; C-60:
121.1; C-70: 124.3; C-5: 127.1; C-6:0128.7; C-4: 130.0; C-3: 130.8; C-40: 132.1; C-2:
0
=
134.4; C-1: 135.1; C-a: 142.1; C-2 : 147.9; C-9 : 157.1; C(C O): 163.4. ESI-MS
(m=z): 315.7919 [M þ H]þ. Anal. calcd. for C16H11ClN2OS (314.79): C, 61.05; H,
3.52. Found: C, 61.10; H, 3.48.
(2E)-N-1,3-Benzothiazol-2-yl-3-(4-chlorophenyl)acrylamide
(Table 2, 3o)
1
The mixture was irradiated for 2 min. Yield: 90%. Mp 242–243 ꢁC. H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.77 (d, 1H, Hb, J ¼ 15.8 Hz), 7.27 (ddd,1H,
0
Ar, H6’), 7.37 (ddd, 1H, Ar, H7 ), 7.42–7.45 (m 2H, Ar, H3, H5), 7.50–7.52 (m,
3
2H, Ar, H2, H6), 7.71 (d, 1H, Ha, J ¼ 15.8 Hz), 7.81 (dd, 1H, Ar, H8’), 7.96 (dd,
13
1H, Ar, H5’), 12.40 (s, 1H, NH). C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC):
C-b: 119.1; C-80: 119.5; C-50: 120.8; C-60: 121.0; C-70: 124.5; C-3, C-5: 128.8; C-2,
C-6: 130.2; C-40: 131.1; C-1: 134.9; C-4: 135.6; Cþ-a: 142.8; C-20: 147.4; C-90: 157.5;
=
C(C O): 164.2. ESI-MS (m=z): 315.7918 [M þ H] . Anal. calcd. for C16H11ClN2OS
(314.79): C, 61.05; H, 3.52. Found: C, 61.08; H, 3.50.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(6-methoxy-1,3-benzothiazol-2-
yl)acrylamide (Table 2, 3p)
1
The mixture was irradiated for 2 min. Yield: 93%. Mp 228–229 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.81, 3.82, 3.84 (s, 3H, OCH3), 6.68 (dd, 1H,
3
Ar, H7’), 6.82 (d, 1H, Hb, J ¼ 15.8 Hz), 7.05 (d, 1H, Ar, H5), 7.16 (dd, 1H, Ar,
H6), 7.24 (d, 1H, Ar, H2), 7.57 (d, 1H, Ar, H5’), 7.65 (d, 1H, Ar, H8’), 7.73 (d,
3
1H, Ha, J ¼ 15.8 Hz), 12.33 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d ppm,
25 ꢁC): C(OCH3): 55.3, 55.4, 55.5, C-50: 104.6; C-2: 110.5; C-5: 111.8; C-70, 114.7;
C-b: 117.9; C-800, 120.9; C-6: 123.1; C-1: 126.9; C-40, 132.9; C-a: 142.7; C-20: 145.8;
0
=
C-3: 148.9; C-9 : 150.3; C-4: 151.0; C-6 : 156.0; C(C O): 163.9. ESI-MS (m=z):
371.4139 [M þ H]þ. Anal. calcd. for C19H18N2O4S (370.42): C, 61.61; H, 4.90.
Found: C, 61.78; H, 4.83.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(6-ethoxy-1,3-benzothiazol-2-
yl)acrylamide (Table 2, 3q)
1
The mixture was irradiated for 2 min. Yield: 91%. Mp 224–225 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 1.35 (t, 3H, OCH2CH3), 3.82, 3.84 (s, 3H,
OCH3), 4.85 (q, 2H, OCH2CH3), 6.69 (dd, 1H, Ar, H7’), 6.80 (d, 1H, Hb,

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
549
3J ¼ 15.2 Hz), 7.03 (d, 1H, Ar, H5), 7.18 (dd, 1H, Ar, H6), 7.28 (d, 1H, Ar, H2), 7.59
3
(d, 1H, Ar, H5’), 7.64 (d, 1H, Ar, H8’), 7.75 (d,1H, Ha, J ¼ 15.2 Hz), 12.31 (s, 1H,
NH). 13C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C(OCH2CH3): 14.3;
C(OCH3): 55.4, 55.5; C(OCH2CH3): 63.5; C-50: 105.7; C-2: 110.8; C-5: 111.9; C-70:
114.9; C-b: 117.5; C-80: 120.7; C-6: 122.9; C-1: 127.0; C-40: 132.6; C-a: 142.4; C-20:
0
0
=
145.3; C-3: 148.8; C-9 : 150.2; C-4: 150.8; C-6 : 152.9; C(C O): 163.8. ESI-MS
(m=z): 385.4508 [M þ H]þ. Anal. calcd. for C20H20N2O4S (384.45): C, 62.48; H,
5.24. Found: C, 62.35; H, 5.38.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(6-methyl-1,3-benzothiazol-2-
yl)acrylamide (Table 2, 3r)
1
The mixture was irradiated for 2 min. Yield: 89%. Mp 227–228 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 2.45 (s, 3H, CH3), 3.80, 3.85 (s, 3H, OCH3),
3
6.83 (d, 1H, Hb, J ¼ 15.6 Hz), 7.03 (d, 1H, Ar, H5), 7.17 (dd, 1H, Ar, H6), 7.21
(dd, 1H, Ar, H7’), 7.26 (d, 1H, Ar, H2), 7.60 (d,1H, Ar, H8’), 7.71 (d, 1H, Ha,
3J ¼ 15.6 Hz), 7.78 (d,1H, Ar, H5’), 12.45 (s, 1H, NH). 13C NMR (75.03 MHz,
DCCl3, d ppm, 25 ꢁC): C(CH3): 20.6; C(OCH3): 55.4, 55.3; C-2: 110.9; C-5: 111.8;
C-b0: 117.3; C-80: 119.7; C-50: 120.8; C-6: 123.9; C-70: 126.9; C-1: 127.2; C-60: 131.6;
0
0
=
C-4 : 132.6; C-a: 142.6; C-2 : 146.4; C-3: 148.9; C-4: 150.9; C-9 : 152.0; C(C O):
163.9. ESI-MS (m=z): 355.4249 [M þ H]þ. Anal. calcd. for C19H18N2O3S (354.42):
C, 64.39; H, 5.12. Found: C, 64.41; H, 5.19.
(2E)-3-(3,4-Dimethoxyphenyl)-N-[6-(methylsulfonyl)-1,3-
benzothiazol-2-yl]acrylamide (Table 2, 3s)
1
The mixture was irradiated for 2 min. Yield: 90%. Mp 196–197 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.12 (s, 3H, CH3), 3.83, 3.85 (s, 3H, OCH3),
3
6.77 (d, 1H, Hb, J ¼ 15.9 Hz), 7.02 (d, 1H, Ar, H5), 7.14 (dd, 1H, Ar, H6), 7.24
3
(d, 1H, Ar, H2), 7.55 (dd, 1H, Ar, H7’), 7.77 (d, 1H, Ha, J 15.9 Hz), 7.89 (d, 1H,
Ar, H8’), 8.23 (d, 1H, Ar, H5’), 12.46 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3,
d ppm, 25 ꢁC): C(CH3): 40.9; C(OCH3): 55.6, 55.7; C-2: 110.6; C-5: 111.7; C-b:
116.8; C-50: 121,5; C-6: 122.7; C-80: 123.1; C-70: 125.6; C-1: 127.1; C-40: 133.5;
0
0
0
=
C-6 : 134.9; C-a: 143.9; C-2 : 147.7; C-3: 149.1; C-4: 151.3; C-9 : 159.5; C(C O):
164.7. ESI-MS (m=z): 419.4901 [M þ H]þ. Anal. calcd. for C19H18N2O5S2 (418.49):
C, 54.53; H, 4.34. Found: C, 54.55; H, 4.29.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(6-nitro-1,3-benzothiazol-2-
yl)acrylamide (Table 2, 3t)
1
The mixture was irradiated for 2 min. Yield: 93%. Mp 230–232 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.81, 3.83 (s, 3H, OCH3), 6.84 (d, 1H, Hb,
3J ¼ 16.1 Hz), 7.04 (d, 1H, Ar, H5), 7.19 (dd, 1H, Ar, H6), 7.25 (d, 1H, Ar, H2),
3
7.77 (d, 1H, Ha, J ¼ 16.1 Hz), 7.88 (d, 1H, Ar, H6’), 8.08 (dd, 1H, Ar, H7’), 8.67
(d, 1H, Ar, H5’), 12.35 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d ppm,
25 ꢁC): C(OCH3): 55.8, 55.6; C-2: 110.8; C-5: 112.0; C-b: 117.0; C-50: 119.1; C-70:
120.6; C-80: 121.9; C-6: 123.2; C-1: 127.0; C-40: 131.8; C-60: 140.4; C-a: 140.9; C-20:

´
R. F. PELLON AND M. L. DOCAMPO
550
0
=
147.1; C-3: 148.6; C-4: 150.7; C-9 : 158.8; C(C O): 161.9. ESI-MS (m=z): 386.3925
[M þ H]þ. Anal. calcd. for C18H15N3O5S (385.39): C, 56.10; H, 3.92. Found: C,
55.97; H, 4.05.
(2E)-N-(4-Chloro-1,3-benzothiazol-2-yl)-3-(3,4-
dimethoxyphenyl)acrylamide (Table 2, 3u)
1
The mixture was irradiated for 3 min. Yield: 88%. Mp 158–159 ꢁC. H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 3.78, 3.80 (s, 3H, OCH3), 6.77 (d, 1H, Hb,
3J ¼ 15.9 Hz), 6.87 (d, 1H, Ar, H5), 7.00 (dd, 1H, Ar, H7’), 7.20 (dd, 1H, Ar, H6),
3
7.27 (d, 1H, Ar, H2), 7.36 (t, 1H, Ar, H6’), 7.75 (d, 1H, Ha, J ¼ 15.9 Hz), 7.79
(dd, 1H, Ar, H5’), 12.52 (s, 1H, NH). 13C NMR (75.03 MHz, DCCl3, d ppm,
25 ꢁC): C(OCH3): 55.8, 55.9; C-2: 110.7; C-5: 111.6; C-b: 116.8; C-50: 120.0; C-80:
121.0; C-60: 121.9; C-6: 122.7; C-70: 124.5; C-1: 127.1; C-40: 132.4; C-a: 142.9; C-20:
0
=
147.8; C-3: 149.2; C-4: 151.4; C-9 : 157.5; C(C O): 164.7. ESI-MS (m=z): 375.8411
[M þ H]þ. Anal. calcd. for C18H15ClN2O3S (374.84): C, 57.68; H, 4.03. Found: C,
57.55; H, 4.18.
(2E)-3-(3,4-Dimethoxyphenyl)-N-(4-methyl-1,3-benzothiazol-2-
yl)acrylamide (Table 2, 3v)
The mixture was irradiated 3 min. Yield: 89%. Mp 204–205 ꢁC. 1H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 2.51 (s, 3H, CH3), 3.82, 3.84 (s, 3H, OCH3),
3
6.69 (dd, 1H, Ar, H7’), 6.78 (d, 1H, Hb, J ¼ 15.8 Hz), 6.99 (d, 1H, Ar, H5), 7.05
(t, 1H, Ar, H6’), 7.12 (dd, 1H, Ar, H6), 7.29 (d, 1H, Ar, H2), 7.68 (dd, 1H, Ar,
3
H5’), 7.74 (d, 1H, Ha, J ¼ 15.8 Hz), 12.51 (s, 1H, NH). 13C NMR (75.03 MHz,
DCCl3, d ppm, 25 ꢁC): C(CH3): 17.9; C(OCH3): 55.6, 55.4; C-2: 110.9; C-5: 111.7;
C-b0: 116.9; C-60: 119.0; C-6:0122.0; C-50: 123.4; C-70: 126.6; C-1: 128.1; C-80: 129.6;
0
=
C-4 : 131.8; C-a: 142.1; C-2 : 145.1; C-3: 149.8; C-4: 150.9; C-9 : 155.2; C(C O):
164.1. ESI-MS (m=z): 355.4199 [M þ H]þ. Anal. calcd. for C19H18N2O3S (354.42):
C, 64.39; H, 5.12. Found: C, 64.47; H, 5.19.
(2E)-N,3-Diphenylacrylamide (Table 2, 3w)
1
The mixture was irradiated for 1 min. Yield: 98%. Mp 293–295 ꢁC. H NMR
3
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.81 (d, 1H, Hb, J ¼ 15.6 Hz), 7.09 (dt,1H,
Ar, H4’), 7.25 (d, 1H, Ar, H4), 7.31 (dd, 2H, Ar, H3’, H5’), 7.44 (dd, 2H, Ar, H3,
3
H5), 7.71 (dd, 2H, Ar, H2’, H6’), 7.77 (d, 1H, Ha, J ¼ 15.6 Hz), 12.00 (s, 1H, NH).
13C NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C-b: 118.3; C-40: 122.2; C-20, C-60:
123.3; C-30, C-50: 127.8; C-3, C-2, C-6: 128.3; C-5: 128.9; C-4: 129.9; C-1: 134.7;
þ
0
=
C-1 : 139.2; C-a: 142.1; C(C O): 165.9. ESI-MS (m=z): 224.2719 [M þ H] . Anal.
calcd. for C15H13NO (223.27): C, 80.69; H, 5.87. Found: C, 80.67; H, 5.88.
4-f[(2E)-3-Phenylprop-2-enoyl]aminogbenzoic acid (Table 2, 3x)
The mixture was irradiated for 1.5 min. Yield: 97%. Mp 152–154 ꢁC. 1H NMR
(300.13 MHz, DCCl3, d ppm, 25 ꢁC): 6.85 (d, 1H, Hb, 3J ¼ 15.9 Hz), 7.39 (dd, 1H, Ar,

SYNTHESIS OF NOVEL CINNAMOYL AMIDES
551
H4), 7.47 (dd, 2H, Ar, H3, H5), 7.57 (d, 2H, Ar, H2’, H6’), 7.63 (dd, 2H, Ar, H2, H6),
3
7.87 (d, 1H, Ha, J ¼ 15.9 Hz), 7.91 (d, 2H, Ar, H3’, H5’), 12.20 (s, 1H, NH). 13C
NMR (75.03 MHz, DCCl3, d ppm, 25 ꢁC): C-b: 118.5; C-20, C-60: 121.8; C-40:
125.2; C-2, C-6: 127.8; C-3, C-5: 129.0; C-4: 130.3; C-30, C-50: 131.4; C-1: 134.5;
0
=
C-a: 141.9; C-1 : 143.2; C(C O): 163.8; C(COOH): 166.9. ESI-MS (m=z): 268.2779
[M þ H]þ. Anal. calcd. for C16H13NO3 (267.28): C, 71.90; H, 4.90. Found: C,
71.94; H, 4.87.
ACKNOWLEDGMENTS
´
´
The authors thank Antonio Marchal Igrain and Juan Jesu´s Lopez Gonzalez
´
from University of Jaen, Spain, for their kindness for measuring NMR spectra.
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