Fast synthesis employing a microwave assisted neat protocol of new monomers potentially useful for the preparation of PDLC films

Article abstract of DOI:10.2478/s11532-011-0046-2

It has been repor ted that the length of the molecular chain and the rigidity of molecules influence the structure of the polymer network in PDLC films and hence the electro-optical proper ties of the composites. Herein, a series of new aromatic monomeric monomethacrylates, bismethacrylates and monovinylbenzene derivatives with a mesogenic core were successfully synthesized under microwave irradiation. The microwave assisted synthesis resulted in decreased reaction times, reduced solvent requirement, increased operational simplicity, and in most cases, improved yields and selectivity. Versita Sp. z o.o.

Full text of DOI:10.2478/s11532-011-0046-2

Cent. Eur. J. Chem. • 9(4) • 2011 • 557-566
DOI: 10.2478/s11532-011-0046-2
Central European Journal of Chemistry
Fast synthesis employing a microwave assisted
neat protocol of new monomers potentially
useful for the preparation of PDLC films
Invited Paper
M. Teresa Barros*, Ana I. Mouquinho, Krasimira T. Petrova,
Mara D. Saavedra, João C. Sotomayor
REQUIMTE, CQFB, Deoartment of Chemistry, Faculty of Science and
Technology, New University of Lisbon, 2829-516 Caparica, Portugal1
Received 19 November 2010; Accepted 10 March 2011
Abstract:
It has been reported that the length of the molecular chain and the rigidity of molecules influence the structure of the polymer
network in PDLC films and hence the electro-optical properties of the composites. Herein, a series of new aromatic monomeric
monomethacrylates, bismethacrylates and monovinylbenzene derivatives with a mesogenic core were successfully synthesized under
microwave irradiation. The microwave assisted synthesis resulted in decreased reaction times, reduced solvent requirement, increased
operational simplicity, and in most cases, improved yields and selectivity.
Keywords: Monomers synthesis • Microwave irradiation • Solventless reactions • Liquid crystals • PDLC films
© Versita Sp. z o.o.
1. Introduction
the liquid crystal domains. In fact the electro-optical
properties and hence the possible marketing of such
devices is deeply influenced by the integrity of the films
over a long period of time. One possible approach toward
this stabilization uses a comonomer with the same
mesogenic unit as the liquid crystal mixture used for the
preparation of PDLC films [9]. Therefore, the focus of
this article is on the design and synthesis of a number of
photo- and thermo-polymerisable monomers, mimicking
some structural elements of the LC, a multicomponent
nematic mixture E7 for better miscibility and compatibility.
For this purpose a number of aromatic mono-and bi-
methacrylates, as well as mono-vinylbenzenes, have
been synthesized. We have developed mild and solvent-
free procedures, with reaction times as short as 1 to
5 min, using microwave (MW) irradiation [10] and which,
in many cases, appears to be a more selective affording
higher yields compared to classical thermal heating [11].
Microwave-enhanced chemistry is based on the efficient
heating of materials by “microwave dielectric heating”
effects. This phenomenon is dependent on the ability of
dipolarmaterials(solventorreagent)toabsorbmicrowave
energy and convert it into heat (tan δ). A reaction medium
with a high tan δ factor is required for efficient absorption
and, consequently, for rapid heating [12].
In the advanced materials field, liquid crystal - polymer
composites have been widely studied in the last two
decades for potential applications such as switchable
windows, displays, color projectors, and other electro–
optical systems [1-3] which are useful in the design
of integrated optical structures and devices. Polymer
dispersed liquid crystal (PDLC) films consist of micron-
sized nematic liquid-crystal (LC) droplets dispersed in a
polymeric matrix [4]. Polymers used for PDLC preparation
should exibit [5]: transparency greater than 95% for layers
with thickness of about 10 µm, high adhesion ability to
the designed substrates (glass or polymer), chemical
stability and inertion to the liquid crystal material, and
surface properties enforcing nucleation of LC droplets
close to a spherical shape. Thus, the microstructure of
the polymer network seriously affects their electro-optical
properties [6-8].
The literature on this topic contains a limited variety of
monomers for applications in PDLC films. We found that
the synthetic work in the field were mainly dedicated to the
preparation of mesogenic compounds to be incorporated
into the polymer matrix, but the polymer chemistry side of
the common PDLC films remained unexplored.
One of the key-points in designing a new polymeric
material for PDLC preparation is the stabilization of
* E-mail: mtbarros@dq.fct.unl.pt
557
1 REQUIMTE, CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal

Fast synthesis employing a microwave assisted
neat protocol of new monomers potentially useful
for the preparation of PDLC films
To the best of our knowledge, the MW-assisted
formation of aromatic methacrylic mono- and diesters,
and aromatic vinylbenzyl ethers by the protocols
described in this article, has not yet been reported.
Aromatic methacrylates are highly reactive
monomers due to the presence of aromatic ring and
thus form an interesting class of polymers. Poly(phenyl
methacrylates) possess high tensile strength, high
thermal stability and high glass transition temperatures.
Therefore, they find wide applications in the preparation
of materials such as photo luminescent [13], photo resist
[14], adhesives for leather [15], photosensitive [16],
biomaterials [17], optical telecommunication materials
[18] and polymer supported catalyst [19], etc. Based
on this information we have developed the synthesis
of a library of compounds with distinct structural
features: monomethacrylated monomers (Fig. 2); bis-
methacrylated monomers (Fig. 3); methacryl esters and
amides with spacer arms (Fig. 5); and vinylbenzenoyl
derivatives (Fig. 6).
5CB
NC
NC
NC
NC
7CB
80CB
O
5CT
Figure 1. Structures of the components of the nematic liquid crystal
mixture E7.
O
O
O
O
O
NH
N-phenylmethacrylamide
Benzyl methacrylate
Phenyl methacrylate
2
3
1
CH3
O
O
O
O
HN
O
N-benzylmethacrylamide
Biphenyl-4-yl methacrylate 1-phenylethyl methacrylate
4
5
6
O
O
A number of photo- and thermo-polymerisable
monomers, 1-27 (Figs. 2-6), have been designed
to mimic some structural elements of the LC (E7,
Fig. 1) [20]. In order to achieve better miscibility during
preparation of PDLC-films, as well a possible control
on the LC microdroplets size, and hence on their
electro-optical properties, several monomers containing
aromatic systems and nitrile groups were synthesized.
Esterification is one of the most general and widely
used reactions in organic chemistry. A well-known
conventional procedure for synthesis of aromatic
methacryl esters and amides is from the corresponding
phenol or amine and methacryl chloride in the presence
NC
O
NC
O
4'-isocyanobiphenyl-4-yl methacrylate
4-isocyanophenyl methacrylate
8
7
Figure 2. Monomethacrylated monomers.
O
O
O
O
O
O
O
NH
O
H
N
1,4-phenylene bis(2-methylacrylate)
O
O
9
N,N'-(1,2-phenylene)bis(2-
methylacrylamide)
10
Biphenyl-2,2'-diyl bis(2-
methylacrylate)
11
O
O
O
N
N
H
H
of
a base, usually triethylamine (Schemes 1,2;
Tables 1,2) [21].
N,N'-(4,4'-oxybis(4,1-phenylene))bis(2-methylacrylamide)
12
The syntheses have been achieved using
a
Microwave Synthetic Reactor under mild and solventless
procedures, in short reaction times. The monomode
reactor is preferentially used in chemistry due to wave
focusing (reliable homogeneity in the electric field) and
thus accurate control of the temperature throughout
the reaction with the possibility of operating with similar
temperature profiles in different experiments.
The protocol employed consisted in placing
equivalent amounts of the corresponding reagents in
a quartz tube, which was then subjected to microwave
irradiation at 200 W and reaction times indicated in
Tables 1-5. The reaction time was optimized by following
the reactions by TLC every 1 min and stopped when no
starting material remained.
Figure 3. Bis-methacrylated monomers.
The experimental conditions and results are listed
in Tables 1-5. The structure and purity of all isolated
1H and 13C NMR, DEPT,
compounds were proven by
COSY, HMQC, FTIR, elemental analyses and melting
point (see Supplemental Information).
Five-carbon spacer arm was introduced to
the structures 13-24 to increase the flexibility
(Scheme 3) and this was carried out as follows. To a
mixtureofthesubstrate(monoorbi-phenol)andK2CO3 in
the minimum amount of DMF necessary to homogenize
the reaction mixture, was added 1,5-dibromopentane,
and the mixture was subjected to MW irradiation to
produce the bromo derivative, after purification. This
intermediate was added to an equimolar mixture of
K2CO3 and methacrylic acid in DMF, and then subjected
to MW irradiation using a preprogrammed potency/
After completion, the reaction was allowed to cool
down to room temperature and after work up, the
product was purified by flash column chromatography.
558

M. T. Barros et al.
O
NEt3
O
(CH2)5
Br
O
(CH2)5
Br
+
O
R
X
R
XH
4-(5-bromopentyloxy)biphenyl
MW
(5-bromopentyloxy)benzene
14
13
Cl
X=O, NH
NC
O
(CH2)5
Br
NC
O
(CH2)5
Br
Scheme 1. Generalschemeforthesynthesisofmonomethacrylated
monomers from the corresponding phenols
or amines.
4-(5-bromopentyloxy)benzonitrile
4'-(5-bromopentyloxy)biphenyl-4-carbonitrile
15
16
O
(CH2)5
Br
Br
(H2C)5
O
O
(CH2)5
Br
O
O
NEt3
+
O
X
R
X
2
HX
R
XH
1,4-bis(5-bromopentyloxy) benzene
MW
17
Br
(H2C)5
O
Cl
X=O, NH
2,2'-bis(5-bromopentyloxy)biphenyl
18
Scheme 2. General scheme for the synthesis of bismethacrylated
Figure 4. Br-intermediates with spacer arm.
monomers.
O
O
Br(CH2)5Br
O
(CH2)5
O
O
(CH2)5 O
R
OH
R
O
(CH2)5Br
K2CO3
DMF, MW
5-(biphenyl-4-yloxy)pentyl methacrylate
5-phenoxypentyl methacrylate
20
19
O
H2C=C(CH3)CO2H
O
O
R
O
(CH2)5
O
NC
O
(CH2)5
O
NC
O
(CH2)5 O
K2CO3
DMF, MW
5-(4'-cyanobiphenyl-4-yloxy)pentyl methacrylate
5-(4-cyanophenoxy)pentyl methacrylate
22
21
Br(CH2)5Br
O
O
O
Br(H2C)5
(CH2)5
O
O
R
O
(CH2)5Br
HO
R OH
O
(H2C)5
O
O
(CH2)5
O
O
(CH2)5 O
K2CO3
DMF, MW
5,5'-(1,4-phenylenebis(oxy)) bis(pentane-
O
O
H2C=C(CH3)CO2H
O
5,1-diyl) bis(2-methylacrylate)
23
O (H2C)5
O
O
R
O
(CH2)5
O
K2CO3
DMF, MW
5,5'-(biphenyl-2,2'-diylbis(oxy))bis(pentane-
5,1-diyl) bis(2-methylacrylate)
24
Scheme 3. General scheme for the synthesis with introducing
of spacer arm between the aromatic system and the
methacrylate group.
Figure 5. Methacryl esters and amides with spacer arm.
NaH
+
R
XH
O
MW
Cl
R
X
O
X=O, NH
1-(phenoxymethyl)-4-vinylbenzene
1-(benzyloxymethyl)-4-vinylbenzene
26
25
Scheme 4. Generalschemeforthesynthesisofmonovinylbenzene
monomers.
O
and 14 [28]. Some others have been mentioned in the
chemical literature, but were lacking full characterization,
which have been provided here, as 4 [29], 9 [30], 10
[25], 11 [31], 13 [32], 15 [33], 16 [34], 25 [35], 26 [36].
The compounds 8, 12, 17, 18, 19, 20, 21, 22, 23, 24 and
27 were new compounds.
H2N
N
H
4-(4-aminophenoxy)-N-(4-vinylbenzyl) benzenamine
27
Figure 6. Monovinylbenzene monomers.
The experimental results showed that microwave
irradiation efficiently promoted the reactions and the
reaction times were remarkably shortened. In some
cases, as compounds 12 and 27, the faster heating
favoured side reactions and/or steric hindrance, resulting
in decreased yields. The procedures for introducing the
5-C spacer unit (Tables 3 and 4) proceeded smoothly
with phenols, but the formation of vinylbenzyl monomers
(Table 5) took place accompanied with side reactions,
and resulted in comparatively lower yields. In this case,
the highest yield achieved was for the monomer 26
(64%).
time protocol (Tables 3, 4). During this procedure it was
necessary to add a small amount of DMF as solvent
(1 mL) because both reagents were solid compounds.
DMF was chosen because of its dipolar nature and ability
to dissolve the starting compounds and the products of
the reactions coupled with a comparatively high boiling
point (153°C).
For the reaction of vinylbenzenes the common
method is by treating the corresponding substrate with
sodium hydride, and then adding the 4-vinylbenzyl
chloride (Scheme 4; Table 5) [22].
In some of the examples we have applied the
method to obtain known compounds, as in the case of
compounds 1 [23], 2 [24], 3 [23], 5 [25], 6 [26], 7 [27]
559

Fast synthesis employing a microwave assisted
neat protocol of new monomers potentially useful
for the preparation of PDLC films
Table 1. Monomethacrylated monomers: 1 eq CH =C(CH )COCl, Table 2. Bis-methacrylated
monomers:
4 eq Et3N, MW 200 W.
2 eq CH2=C(CH3)COCl,
2
3
2 eq Et3N, MW 200 W.
Reaction
time [min]
Yield
[%]
Reaction
time [min]
Yield
[%]
Product
Substrate
Product
Substrate
9
Hydroquinone
1,2-Phenylenediamine
2,2’-Biphenol
1
1
1
3
85
80
86
40
1
2
3
4
5
6
7
Phenol
Aniline
1
5
1
5
1
5
2
95
70
96
68
76
49
70
10
11
12
Benzyl alcohol
Benzylamine
4,4’-Oxydianiline
4-Phenylphenol
1-Phenylethanol
4-Cyanophenol
4’-Hydroxy-4-
biphenylcarbonitrile
Table 3. Introducing of spacer arm between the aromatic system
and the methacrylate group – synthesis of Br-intermediates:
Br(CH2)5Br, K2CO3, DMF, MW 200 W.
8
1
88
Reaction
time [min]
Yield
[%]
Product
Substrate
Additionally, in Table 6 we have compared the
microwave conditions with classical synthetic methods
found in the literature, for the compounds 2, 5, 6, 7
and 14. When using microwave irradiation, the yields
obtained were not always higher, but once again, the
results highlight the efficiency of microwave irradiation
to promote chemical reactions and to reduce reaction
time from hours to minutes.
In summary, we have provided a simple and
effective method for the synthesis of structurally diverse
functionalized monomers. The general approach to
synthesize a diverse compound collection from a
common substrate with different reagents provided
efficient access to collections of small molecules bearing
double bond to be screened as monomers for obtaining
new type of PDLC films.
13
14
15
16
Phenol
5
3
5
2
81
79
70
75
4-Phenylphenol
4-Cyanophenol
4’-Hydroxy-4-
biphenylcarbonitrile
Hydroquinone
2,2’-Biphenol
17
18
5
5
50
62
the microwave cavity, and subjected to MW irradiation
of 200 W for the required time (Table 1). After that the
mixture was dissolved in CH2Cl2 and washed with water
to neutral pH. The organic phase was dried, filtered, and
concentrated. The residue was purified by flash column
chromatography with hexane/ethyl acetate (gradient
from 1:1 to 1:2) to afford monomers 1, 2, 3 and 4 and
(gradient from 5:1 to 1:1) to afford monomers 5, 6, 7
and 8.
Phenyl methacrylate 1
1.64 g, 95%
2. Experimental Procedure
1H NMR (400 MHz, CDCl3) δ ppm 7.39 (t, J = 7.9 Hz, 2H,
Ar-H), 7.23 (t, J = 7.4 Hz, 1H, Ar-H), 7.12 (d, J = 7.6 Hz,
2H, Ar-H), 6.35 (s, 1H, CH2a), 5.75 (s, 1H, CH2b), 2.06
(s, 3H, CH3). 13C-RMN (CDCl3) δ 165.8 (C=O), 150.9
(Cq-Ar), 135.9 (Cq), 129.4 (C-Ar), 127.1 (CH2=), 125.7
(C-Ar), 121.6 (C-Ar), 18.4 (CH3). White oil. The data
were according to Aldrich® (reference 392162-15 mL).
N-phenylmethacrylamide 2 [24]
2.1. General Methods
Reagents and solvents were purified before use [38]
NMR spectra were recorded at 400 MHz on a Bruker
AMX-400 instrument in CDCl3 with chemical shift values
(δ) reported in ppm downfield from TMS. FTIR spectra
were recorded on Perkin-Elmer Spectrum BX apparatus
inKBrdispersions.Thereactionswereperformedusinga
MicroSynth Labstation (MileStone, USA) in open flasks,
equipped with a temperature control sensor and under
magnetic stirring [39]. The reactions were followed by
TLC every 1 min and stopped when no starting material
was observed or undesired products started to form.
1.21 g, 70%
1H NMR (400 MHz, CDCl3) δ ppm 7.56 (d, J = 7.9
Hz, 2H, Ar-H), 7.36-7.30 (m, 2H, Ar-H), 7.14-7.09 (m,
1H, Ar-H), 5.79 (s, 1H, CH2a), 5.45 (s, 1H, CH2b), 2.06
(s, 3H, CH3). 13C-RMN (CDCl3) δ 166.6 (C=O), 140.9
(Cq=), 137.8 (Cq-Ar), 129.0 (C-Ar), 124.4 (C-Ar), 120.0
(CH2=), 119.8 (C-Ar), 18.7 (CH3). FTIR (NaCl, cm-1): ν
3290 (NH), δ 1595 (NH), γ 891(NH), ν 1660 (C=O), ν
1620 (CH2=C) and 1494 (aromatic C=C), ν 1436 (C-N),
ν 1373 (CH3). White solid, mp: 180-189ºC. Anal. Calcd
for C10H11NO: C,73.92; H,6.96; N,8.61. Found: C,74.01;
H,6.88; N,8.69. The data were corresponding to the
literature [24].
2.2. Monomers Synthesis
2.2.1. Synthesis of monomethacrylated monomers 1-8
To 1.000 g of the corresponding phenol or amine under
Ar were added 2 eq triethylamine. The mixture was
cooled to 0°C in an ice bath, and 1 eq methacryl chloride
was added slowly. The reaction mixture was placed in
560

M. T. Barros et al.
Table 4. Synthesis of methacryl esters with spacer arm: CH =C(CH ) Table 5. Monovinylbenzene monomers: CH =CHC H CH Cl, NaH,
2
3
2
6
4
2
CO2H, K2CO3, DMF, MW 200W.
DMF, MW 200W.
Reaction
time [min]
Yield
[%]
Reaction
time [min]
Yield
[%]
Product
Substrate
Product
Substrate
19
20
21
22
23
24
13
14
15
16
17
18
5
1
5
1
5
5
70
75
65
65
85
68
25
26
27
Phenol
1
2
5
63
64
27
Benzyl alcohol
4,4’-Oxydianiline
Table 6. Comparison between the results of the MW and
conventional conditions described in the literature.
Reaction
conditions
Yield
[%]
Conventional
conditions, reference
Yield
[%]
Nº
Benzyl methacrylate 3
1.56 g, 96%
2
200 W, 5 min
200 W, 1 min
200 W, 5 min
200 W, 2 min
200 W, 3 min
70
76
49
70
79
0°C for 1 h and r.t. for 4 h [24]
0°C for 2 h and r.t. for 1 h [37]
enzyme, r.t. [26]
70
70
50
75
37
1H NMR (400 MHz, CDCl3) δ ppm 7.34 (m, 5H, Ar-H),
6.16 (s, 1H, =CH2a), 5.58 (s, 1H, =CH2b), 5.19 (s, 2H,
CH2), 1.97 (s, 3H, CH3). 13C-RMN (CDCl3) δ 167.2
(C=O), 136.2 (Cq-Ar), 136.1 (Cq), 128.5 (C-Ar), 128.1
(C-Ar), 127.9 (C-Ar), 125.7 (CH2=), 66.3 (CH2), 18.3
(CH3). White oil. The data were according to Aldrich®
(reference 409448-250 mL).
5
6
7
0°C for 2 h and r.t. for 1 h [27]
Reflux for 20 h [28]
14
δ ppm 166.6 (C=O), 141.9 (Cq-Ar), 136.6 (Cq=), 128.4
(C-Ar), 127.7 (C-Ar), 125.9 (C-Ar), 125.4 (CH2=), 72.5
(CH), 22.3 (CH3-CH), 18.4 (CH3-C=). FTIR (NaCl, cm-1):
ν 1713 (C=O), ν 1637 and 1495 (aromatic C=C), ν
1637 (CH2=C), ν 1378 (CH3). White oil. Anal. Calcd for
C12H14O2: C, 76.17; H, 6.92. Found: C, 76.24; H, 7.07.
The data were corresponding to the literature [26].
4-isocyanophenyl methacrylate 7 [27]
N-benzylmethacrylamide 4 [29]
1.11 g, 68%
1H NMR (400 MHz, CDCl3) δ ppm 7.32 (m, 5H, Ar-H),
5.72 (s, 1H, =CH2a), 5.35 (s, 1H, =CH2b), 4.50 (d, J =
5.5 Hz, 2H, CH2), 1.99 (s, 3H, CH3). 13C-RMN (CDCl3)
δ 168.3 (C=O), 139.8 (Cq), 138.2 (Cq-Ar), 128.7 (C-Ar),
127.8(C-Ar),127.5(C-Ar),119.7(=CH2),43.7(CH2),18.7
(CH3). FTIR (NaCl, cm-1): ν 3450 (NH), δ 1515 (NH), γ
736 (NH), ν 1667 (C=O), ν 1625 (CH2=C) and (aromatic
C=C), ν 1454 (CN), ν 1422 (CH2), ν 1375 (CH3). White
solid, mp 79-84ºC. Anal. Calcd for C11H13NO: C,75.40;
H,7.48; N,7.99. Found: C,74.94; H,7.60; N,8.15.
Biphenyl-4-yl methacrylate 5 [25]
1.10 g, 70%
1H NMR (400 MHz, CDCl3) δ ppm 7.71 (d, J = 8.6 Hz,
2H, Ar-H), 7.30-7.25 (m, 2H, Ar-H), 6.38 (s, 1H, =CH2a),
5.83 (s, 1H, =CH2b), 2.07 (s, 3H, CH3). 13C NMR (100
MHz, CDCl3) δ ppm 164.8 (C=O), 154.2 (CqAr-O), 135.2
(Cq=), 133.7 (C-Ar), 128.4 (=CH2), 123.6 (C-Ar), 118.2
(CN), 109.7 (CqAr-CN), 18.2 (CH3). FTIR (NaCl, cm-1): ν
2232 (CN), ν 1736 (C=O), ν 1637 (CH2=C), ν 1602 and
1451 (aromatic C=C), ν 1378 (CH3), ν 1266 (C-O). Yellow
solid, mp: 78-85ºC Anal. Calcd for C11H9NO2: C, 70.58;
H, 4.85; N, 7.48. Found: C, 70.45; H, 5.01; N, 7.35. The
data were corresponding to the literature [27].
1.15 g, 76%
1H NMR (400 MHz, CDCl3) δ ppm 7.59 (dd, J = 10.6, 8.45
Hz, 4H, Ar-H), 7.44 (t, J = 7.6 Hz, 2H, Ar-H), 7.36 (d, J =
7.3 Hz, 1H, Ar-H), 7.22 (t, J = 12.3 Hz, 2H, Ar-H), 6.38
(s, 1H, =CH2a), 5.78 (s, 1H, =CH2b), 2.09 (s, 3H, CH3).
13C NMR (100 MHz, CDCl3) δ ppm 165.9 (C=O), 150.3
(CqAr-O), 140.4 (Cq-Ar), 138.9 (Cq=), 135.9 (Cq-Ar), 128.8
(C-Ar), 128.1 (C-Ar), 127.3 (C-Ar), 127.1 (C-Ar), 121.9
(=CH2), 18.4 (CH3). FTIR (NaCl, cm-1): ν 1734 (C=O), ν
1638 and 1485 (aromatic C=C), ν 1638 (CH2=C), ν 1378
(CH3), ν 1128 (C-O). White solid, mp:101-106ºC. Anal.
Calcd for C16H14O2: C, 80.65; H, 5.92. Found C, 80.70;
H, 6.05. The data were corresponding to the literature
[37].
4’-isocyanobiphenyl-4-yl methacrylate 8
1.19 g, 88%
1H NMR (400 MHz, CDCl3) δ ppm 7.69 (dd, J1 = 8.19 Hz,
J2 = 23.74 Hz, 4H, Ar-H), 7.60 (d, J = 8.48 Hz, 2H, Ar-H),
7.24 (d, J = 8.51 Hz, 1H, Ar-H), 6.38 (s, 1H, =CH2a),
5.80 (s, 1H, =CH2b), 2.08 (s, 3H, CH3). 13C NMR (100
MHz, CDCl3) δ ppm 165.7 (C=O), 151.4 (CqAr-O), 144.7
(CqAr-Ar), 136.7 (CqAr-Ar), 135.6 (Cq=), 132.6 (C-Ar),
128.3 (C-Ar), 127.6 (CH2=), 122.3 (C-Ar), 118.8 (CN),
110.9 (CqAr-CN), 18.3 (CH3). FTIR (NaCl, cm-1): ν 2229
(NC), ν 1732 (C=O), ν 1608 and 1421 (aromatic C=C),
ν 1320 (CH3), ν 1169 (C-O). White solid, mp 124-129ºC
Anal. Calcd for C17H13NO2: C, 77.55; H, 4.98; N, 5.32; O
12.15. Found: C, 77.70; H, 5.10; N, 5.43.
1-phenylethyl methacrylate 6 [26]
0.76 g, 49%
1H NMR (400 MHz, CDCl3) δ ppm 7.31 (m, 5H, Ar-H),
6.16 (s, 1H, =CH2a), 5.94 (q, J = 6.6 Hz, 1H, =CH2b),
5.64-5.53 (m, 1H, CH), 1.96 (s, 3H, CH3-C=), 1.57 (d,
J = 6.6 Hz, 3H, CH3-CH). 13C NMR (100 MHz, CDCl3)
561

Fast synthesis employing a microwave assisted
neat protocol of new monomers potentially useful
for the preparation of PDLC films
=CH2a), 5.45 (s, 2H, =CH2b), 1.99 (s, 6H, CH3). 13C-RMN
(CDCl3) δ ppm 166.5 (C=O), 153.9 (CqAr-O), 140.8 (Cq=),
133.1 (CqAr-N), 121.8 (C-Ar), 119.8 (CH2=), 119.2 (C-Ar),
18.7 (CH3). FTIR (KBr, cm-1) ν 3281 (NH), δ 1529 (NH),
γ 837(NH), ν 1663 (C=O) and (CH2=C), ν 1625 and 1452
(aromatic C=C), ν 1371 (CH3), ν 1226 (C-O). White solid,
mp: 78-83ºC. Anal. Calcd for C20H20N2O3: C, 71.41; H,
5.99; N, 8.33. Found: C, 71.55; H, 6.04; N, 8.24.
2.2.2. Synthesis of bis-methacrylated monomers 9-12
To 1.000 g of the corresponding biphenol or diamine
underAr were added 4 eq triethylamine. The mixture was
cooled to 0°C in ice bath, and 2 eq methacryl chloride or
anhydride was added slowly. The reaction mixture was
placed in the microwave cavity, and subjected to MW
irradiation of 200 W for the required time (Table 2). After
that the mixture was dissolved in CH2Cl2 and washed
with water to neutral pH. The organic phase was dried,
filtered, and concentrated. The residue was purified by
flash column chromatography with hexane/ethyl acetate
(gradient from 1:1 to 1.2) to afford monomers 9, 12 and
gradient from 5:1 to 1:1 to afford monomers 10, 11.
1,4-phenylene bis(2-methylacrylate) 9 [30]
1.90 g, 85%
1H NMR (400 MHz, CDCl3) δ ppm 7.14 (s, 4H, Ar-H),
6.34 (s, 2H, =CH2a), 5.75 (s, 2H, =CH2a), 2.05 (s, 6H,
CH3). 13C NMR (100 MHz, CDCl3) δ ppm 165.6 (C=O),
148.2 (CqAr-O), 135.6 (Cq=), 127.3 (CH2=), 122.3 (C-Ar),
18.3 (CH3). FTIR (NaCl, cm-1) ν 1736 (C=O), ν 1638
(CH2=C) ν 1638 and 1502 (aromatic C=C), ν 1380 (CH3),
ν 1265 (C-O). White solid, mp: 86-93ºC. Anal. Calcd for
C14H14O4: C, 68.28; H, 5.73.Found: C, 68,17; H 5.86.
N,N’-(1,2-phenylene)bis(2-methylacrylamide) 10
[25]
2.2.3. Synthesis of brominated intermediates 13-18
To a suspension of 2 eq (mono-) or 4 eq K2CO3 (bi-
substituted derivatives) in 1 mL DMF was added 1.000 g
of the corresponding phenol, then 1 eq for mono- or 2 eq
for bi-substituted derivatives of 1,5-dibromopentane was
added slowly. Thus obtained mixture was subjected to
MW irradiation of 200 W for the required time (Table 3).
After that the reaction mixture was dissolved in diethyl
ether, washed with dist. water, and the organic phase
was dried, filtered and concentrated. The residue was
purified by flash column chromatography with hexane/
ethyl acetate (gradient from 5:1 to 1:1) to afford the
compounds 13-18.
(5-bromopentyloxy)benzene 13 [32]
2.09 g, 81%
1H NMR (400 MHz, CDCl3) δ ppm 7.36-7.18 (m, 2H,
Ar-H), 6.95-6.86(m, 3H,Ar-H), 4.01-3.92(m, 2H, CH2-O),
3.46-3.41 (m, 2H, CH2-Br), 1.97-1.89 (m, 2H, CH2), 1.86-
1.76 (m, 2H, CH2), 1.67-1.57 (m, 2H, CH2). 13C NMR
(100 MHz, CDCl3) δ 159.0 (CqAr), 129.4 (C-Ar), 120.6
(C-Ar), 114.4 (C-Ar), 67.4 (CH2-O), 33.5 (CH2-Br), 32.5
(CH2), 28.4 (CH2), 24.8 (CH2). FTIR (NaCl,cm-1) ν 1598
and 1473 (aromatic C=C), ν 1389(CH2), ν 1171(C-O), ν
1152 (CH2-Br). White oil. Anal. Calcd for C11H15BrO: C,
54.34; H, 6.22; Br, 32.86; Found: C, 54.40; H, 6.34; Br,
32.92.
1.81 g, 80%
1H NMR (400 MHz, CDCl3) δ ppm 8.86 (s, 2H, NH), 7.28
(dd, J = 5.75, 3.74 Hz, 2H, Ar-H), 7.07 (dd, J = 5.83, 3.56
Hz, 2H, Ar-H), 5.92 (s, 2H, =CH2a), 5.48 (s, 2H, =CH2b),
2.00 (s, 6H, CH3). 13C-RMN (CDCl3) δ ppm 167.3 (C=O),
139.1 (Cq=), 130.6 (Cq-Ar), 125.9 (C-Ar), 125.7 (CH2=),
121.8 (C-Ar), 18.5 (CH3). FTIR (NaCl,cm-1) ν 3419 (NH),
δ 1509 (NH), γ 739 (NH), ν 1654 (C=O), ν 1626 and
1478 (aromatic C=C), ν 1626 (C=C), ν 1446 (C-N), ν
1375 (CH3). Yellow solid, mp: 119-123ºC Anal. Calcd
for: C14H16N2O2: C, 68.83; H, 6.60; N, 11.47. Found: C,
68.75; H, 6.68; N, 11.53.
4-(5-bromopentyloxy)biphenyl 14 [28]
1.60 g, 79%
1H NMR (400 MHz, CDCl3) δ ppm 7.52 (dd, J = 13.54,
8.06 Hz, 4H, Ar-H), 7.40 (t, J = 7.60 Hz, 2H, Ar-H), 7.28
(t, J = 7.30 Hz, 1H, Ar-H), 6.94 (d, J = 8.63 Hz, 2H,
Ar-H), 3.98 (t, J = 6.29 Hz, 2H, CH2-O), 3.40 (td, J =
16.62, 6.72 Hz, 2H, CH2-Br), 2.01-1.88 (m, 2H, CH2),
1.88-1.76 (m, 2H, CH2), 1.59 (tdd, J = 14.97, 9.58, 7.64
Hz, 2H, CH2). 13C NMR (100 MHz, CDCl3) δ ppm 158.5
(CqAr-O), 140.8 (CqAr-Ar), 133.6 (CqAr-Ar), 128.7 (C-Ar),
128.1 (C-Ar), 126.6 (C-Ar), 114.7 (C-Ar), 67.58 (CH2-O),
33.6 (CH2-Br), 32.4 (CH2), 28.4 (CH2), 24.8 (CH2). FTIR
(NaCl, cm-1): ν 1610 and 1519 (aromatic C=C), 1487 ν
(CH2), 1285 ν (CH2-Br), 1246 ν (C-O). White solid, mp:
50-53ºC Anal. Calcd for C17H19BrO: C, 63.96; H, 6.00;
Br, 25.03. Found: C, 64.00; H, 6.09, Br, 25.07. Which
were corresponding to the literature [28].
Biphenyl-2,2’-diyl bis(2-methylacrylate) 11 [31]
1.49 g, 86%
1H NMR (400 MHz, CDCl3) δ ppm 7.19-7.39 (m, 8H,
Ar-H), 6.02 (s, 2H, =CH2a), 5.53 (s, 2H, =CH2b), 1.83
(s, 6H, CH3). 13C NMR (100 MHz, CDCl3) δ ppm 165.4
(C=O), 148.3 (CqAr-O), 135.4 (Cq=), 131.1 (CqAr-Ar), 128.8
(C-Ar), 126.9 (CH2=), 125.6 (C-Ar), 122.2 (C-Ar), 18.1
(CH3). FTIR (NaCl, cm-1) ν 1734 (C=O), ν 1678 (CH2=C),
ν 1638 and 1504 (aromatic C=C), ν 1378 (CH3), ν 1267
(C-O). White oil. Anal. Calcd for C20H18O4:C, 74.52; H,
5.63. Found: C, 74.68; H, 5.69.
N,N’-(4,4’-oxybis(4,1-phenylene))bis(2-
methylacrylamide) 12
0.67 g, 40%
1H NMR (400 MHz, CDCl3) δ 7.72 ppm (d, J = 8.96 Hz,
4H, Ar-H), 6.95 (d, J = 8.97 Hz, 4H, Ar-H), 5.81 (s, 2H,
562

M. T. Barros et al.
4-(5-bromopentyloxy)benzonitrile 15 [33]
0.94 g, 70%
1H NMR (400 MHz, CDCl3) δ ppm 7.58 (d, J = 8.57 Hz,
White oil. Anal. Calcd for C22H28Br2O2: C, 54.56; H, 5.83;
Br, 33.00; Found:C, 54.50; H, 5.49; Br, 33.04.
2H, Ar-H), 6.93 (d, J = 8.57 Hz, 2H, Ar-H), 4.02 (t, J = 2.2.4. Synthesis of methacryl esters with spacer arm
6.25 Hz, 2H, CH2-O), 3.45 (t, J = 6.65 Hz, 2H, CH2-Br), 19-24
2.00-1.90 (m, 2H, CH2), 1.89-1.79 (m, 2H, CH2), 1.71- 1.000 g of the intermediates 13-18 were added slowly
1.58 (m, 2H, CH2). 13C NMR (100 MHz, CDCl3) δ ppm to equimolar mixture of K2CO3 and methacrylic acid in
162.2 (CqAr-O), 133.9 (C-Ar), 119.2 (CN), 115.1 (C-Ar), 1 mL DMF while stirring. The mixture was subjected to
103.8 (CqAr-CN), 67.9 (CH2-O), 33.4 (CH2-Br), 32.3 MW irradiation of 200W for the required time (Table 4).
(CH2), 28.1 (CH2), 24.7 (CH2). FTIR (NaCl, cm-1) ν 2226 After that the reaction mixture was dissolved in diethyl
(NC), ν 1606 and 1508 (aromatic C=C), ν 1470 (CH2), ν ether and washed with dist. water. The organic phase
1264 (C-O), ν 1172 (CH2-Br). White solid, mp: 53-56ºC was dried, filtered and concentrated. The residue was
Anal. Calcd for C12H14BrNO: C, 53.75; H, 5.26; Br, 29.80; purified by flash column chromatography with hexane/
N, 5.22. Found: C, 53.79; H, 5.27; Br, 29.88; N, 5.20.
4’-(5-bromopentyloxy)biphenyl-4-carbonitrile 16 19 and gradient from 5:1 to 1:1 to afford monomers 20-
[34] 24.
1.32 g, 75%
ethyl acetate (gradient from 1:1 to 1:2) to afford monomer
5-phenoxypentyl methacrylate 19
1H NMR (400 MHz, CDCl3) δ ppm 7.60-7.54 (m, 4H, 0.71 g, 70%
Ar-H), 6.94 (d, J = 8.33 Hz, 4H, Ar-H), 4.02 (t, J = 6.17 1H NMR (400 MHz, CDCl3) δ 7.32-7.20 (m, 2H, Ar-H),
Hz, 2H, CH2-O), 3.44 (t, J = 6.59 Hz, 2H, CH2-Br), 2.01- 6.94-6.87 (m, 3H, Ar-H), 6.10 (s, 1H, CH2a), 5.55 (s, 1H,
1.89 (m, 2H, CH2), 1.85 (td, J = 13.84, 9.30 Hz, 2H, CH2b), 4.21-4.15 (m, 2H, CH2-OOC), 3.99-3.95 (m, 2H,
CH2), 1.65 (m, 2H, CH2). 13C NMR (100 MHz, CDCl3) δ CH2-OAr), 1.95 (s, 3H, CH3), 1.87-1.80 (m, 2H, CH2),
ppm 162.1 (CqAr-O), 145.1 (CqAr-Ar), 133.8 (C-Ar), 132.7 1.79-1.73 (m, 2H, CH2), 1.62-1.55 (m, 2H, CH2). 13C
(CqAr-Ar), 128.8 (C-Ar), 119.1 (CN), 115.1 (C-Ar), 103.6 NMR (100 MHz, CDCl3) δ 167.4 (C=O), 159.0 (CqAr-O),
(CqAr-CN), 67.9 (CH2-O), 33.4 (CH2-Br), 32.2 (CH2), 28.0 136.4 (Cq=); 129.4 (C-Ar), 125.2 (CH2=), 120.5 (C-Ar),
(CH2), 24.6 (CH2). FTIR (NaCl, cm-1) ν 2226 (NC), ν 114 (C-Ar), 67.4 (CH2-O), 64.5 (CH2-OOC), 29.0 (CH2),
1604 and 1494 (aromatic C=C), ν 1472 (CH2), ν 1265 28.3 (CH2), 22.6 (CH2), 18.3 (CH3). FTIR (NaCl,cm-1) ν
(C-O), ν 1179 (CH2-Br). White solid, mp 82-84ºC. Anal. 1637 (C=O), ν 1599 and 1454 (aromatic C=C), ν 1401
Calcd for C18H18BrNO: C, 62.80; H, 5.27; Br 23.21; N, (CH2), ν 1168(C-O). White oil, Anal. Calcd for C15H20O3:
4.07. Found: C, 62.78; H, 5.37; Br 23.29; N,3.97.
1,4-bis(5-bromopentyloxy)benzene 17
1.85 g, 50%
C, 72.55; H, 8.12; Found: C, 72.50; H, 8.04.
5-(biphenyl-4-yloxy)pentyl methacrylate 20
0.76 g, 75%
1H NMR (400 MHz, CDCl3) δ 6.82 (s, 4H, Ar-H), 3.92 (t, 1H NMR (400 MHz, CDCl3) δ ppm 7.53 (dd, J = 13.46,
J=6.2 Hz, 4H, CH2-O), 3.43 (q, J=6.9 Hz, 4H, CH2-Br), 8.05 Hz, 4H, Ar-H), 7.41 (t, J = 7.57 Hz, 2H, Ar-H), 7.29
1.95-1.88 (m, 4H, CH2), 1.80-1.75 (m, 4H, CH2), 1.63- (t, J = 7.24 Hz, 1H, Ar-H), 6.96 (d, J = 8.52 Hz, 2H, Ar-H),
1.58 (m, 4H, CH2).13C NMR (100 MHz, CDCl3) δ 153.1 6.11 (s, 1H, =CH2a), 5.55 (s, 1H, =CH2b), 4.19 (t, J = 6.49
(CqAr-O), 115.4 (C-Ar), 68.2 (CH2-O), 33.6 (CH2-Br), 32.5 Hz, 2H, CH2-OOC), 4.01 (t, J = 6.29 Hz, 2H, CH2-OAr),
(CH2), 28.6 (CH2), 24.9 (CH2). FTIR (NaCl, cm-1) ν 1637 1.95 (s, 3H, CH3), 1.90-1.81 (m, 2H, CH2), 1.81-1.71 (m,
and 1508 (aromatic C=C), ν 1420 (CH2), ν 1265 (C-O), 2H, CH2), 1.59 (m, 2H, CH2). 13C NMR (100 MHz, CDCl3)
ν 1170 (CH2-Br). White solid, mp 94-99ºC Anal. Calcd δ ppm 167.5 (C=O), 158.6 (CqAr-O), 140.8 (CqAr-Ar), 136.4
for C16H24Br2O2: C, 47.08; H, 5.93; Br, 39.15; Found: C, (Cq=), 133.6 (CqAr-Ar), 129.4 (C-Ar), 128.8 (C-Ar), 128.0
46.99; H, 6.00; Br, 39.19.
2,2’-bis(5-bromopentyloxy)biphenyl 18
1.61 g, 62%
(C-Ar), 127.4 (C-Ar), 125.9 (CH2=), 115.4 (C-Ar), 114.1
(C-Ar), 67.7 (CH2-O), 64.5 (CH2-OOC), 28.9 (CH2), 28.4
(CH2), 22.6 (CH2), 17.8 (CH3). FTIR (NaCl, cm-1) ν 1710
1H NMR (400 MHz, CDCl3) δ ppm 7.31-7.20 (m, 4H, (C=O), ν 1654 (CH2=C), ν 1638 and 1518 (aromatic
Ar-H), 7.01-6.88 (m, 4H, Ar-H), 3.90 (t, J = 6.12 Hz, 4H, C=C), ν 1420 (CH2), ν 1321 (CH3), ν 1265 (C-O). White
CH2-O), 3.27 (t, J = 6.72 Hz, 4H, CH2-Br), 1.80-1.68 (m, solid, mp: 30-34ºC. Anal. Calcd for C21H24O3: C, 77.75;
4H, CH2), 1.67-1.57 (m, 4H, CH2), 1.41 (m, 4H, CH2). H, 7.46. Found: C, 77.86; H, 7.56.
13C NMR (100 MHz, CDCl3) δ ppm 156.4 (CqAr-O), 131.4
5-(4-cyanophenoxy)pentyl methacrylate 21
(CqAr-Ar, C-Ar), 128.3 (C-Ar), 120.2 (C-Ar), 112.2 (C-Ar), 0.66 g, 65%
68.1 (CH2-O), 33.8 (CH2-Br), 32.2 (CH2), 28.3 (CH2), 1H NMR (400 MHz, CDCl3) δ ppm 7.57 (d, J = 8.75 Hz,
24.8 (CH2). FTIR (NaCl, cm-1) ν 1637 and 1498 (aromatic 2H, Ar-H), 6.94 (d, J = 8.75 Hz, 2H, Ar-H), 6.10 (s, 1H,
C=C), ν 1443 (CH2), ν 1266 (C-O), ν 1127 (CH2-Br). =CH2a), 5.56 (s, 1H, =CH2b), 4.19 (t, J = 6.50 Hz, 2H,
563

Fast synthesis employing a microwave assisted
neat protocol of new monomers potentially useful
for the preparation of PDLC films
CH2-OOC), 4.02 (t, J = 6.30 Hz, 2H, CH2-O), 1.95 (s, CH3), 1.69-1.62 (m, 4H, CH2), 1.62-1.52 (m, 4H, CH2),
3H, CH3), 1.91-1.81 (m, 2H, CH2), 1.81-1.72 (m, 2H, 1.35 (m, 4H, CH2). 13C NMR (100 MHz, CDCl3) δ ppm
CH2), 1.59 (dd, J = 15.31, 8.12 Hz, 2H, CH2). 13C NMR 167.3 (C=O), 156.4 (CqAr-O), 136.4 (Cq=), 131.4 (CqAr-Ar,
(100 MHz, CDCl3) δ ppm 167.3 (C=O), 162.1 (CqAr-O), C-Ar), 128.3 (C-Ar), 125.1 (CH2=), 120.1 (C-Ar), 112.2
136.3 (Cq=), 133.3 (C-Ar), 125.2 (=CH2), 119.2 (CN), (C-Ar), 68.1 (CH2-O), 64.5 (CH2-OOC), 28.8 (CH2),
115.0 (C-Ar), 109.9 (CqAr-CN), 67.9 (CH2-O), 64.3 (CH2- 28.2 (CH2), 22.6 (CH2), 18.2 (CH3). FTIR (NaCl, cm-1) ν
OOC), 28.5 (CH2), 28.2 (CH2), 22.4 (CH2), 18.8 (CH3). 1720 (C=O), ν 1600 and 1503 (aromatic C=C), ν 1636
FTIR (NaCl, cm-1) ν 2226 (NC), ν 1712 (C=O), ν 1607 (CH2=C), ν 1443 (CH2), ν 1359 (CH3), ν 1296 (C-O).
and 1508 (aromatic C=C), ν 1421 (CH2), ν 1321 (CH3), White oil. Anal. Calcd for C30H38O6: C, 72.85; H, 7.74.
ν 1266 (C-O). White solid, mp 41-50ºC. Anal. Calcd for Found: C, 72.80; H, 7.70.
C16H19NO3: C, 70.31; H, 7.01; N, 5.12. Found: C, 70.41;
H, 7.06; N, 5.14.
2.2.5. Synthesis of vinylbenzene monomers 25-27
5-(4’-cyanobiphenyl-4-yloxy)pentyl methacrylate To a cooled to 0°C in an ice bath mixture of 1.000 g of the
22
0.66 g, 65%
corresponding phenol or amine with a catalytic amount of
Bu4N+I- and 1 mLDMF, were added 2 eq NaH, and stirred
1H NMR (400 MHz, CDCl3) δ ppm 7.65 (dd, J = 19.01, underAr.After 20 min were added 2 eq 1-(chloromethyl)-
8.16 Hz, 4H, Ar-H), 7.52 (d, J = 8.43 Hz, 2H, Ar-H), 6.98 4-vinylbenzene slowly. The reaction mixture was placed
(d, J = 8.44 Hz, 2H, Ar-H), 6.11 (s, 1H, =CH2a), 5.56 (s, in the microwave cavity, and subjected to MW irradiation
1H, =CH2b), 4.19 (t, J = 6.48 Hz, 2H, CH2-OOC), 4.02 (t, of 200 W for the required time (Table 5). After that the
J = 6.25 Hz, 2H, CH2-O), 1.95 (s, 3H, CH3), 1.92-1.82 mixture was dissolved in CH2Cl2, and washed with water
(m, 2H, CH2), 1.77 (m, 2H, CH2), 1.60 (dd, J = 15.09, to neutral pH. The organic phase was dried, filtered, and
7.99 Hz, 2H, CH2). 13C NMR (100 MHz, CDCl3) δ ppm concentrated. The residue was purified by flash column
167.4 (C=O), 159.6 (CqAr-O), 145.1 (CqAr-Ar), 136.4 (Cq=), chromatography with hexane/ethyl acetate (gradient
132.44 (CqAr-Ar, C-Ar), 131.2 (C-Ar), 128.2 (C-Ar), 127.0 from 1:1 to 1:2) to afford monomer 27 and gradient from
(C-Ar), 125.2 ((=CH2), 119.0 (CN), 115.0 (C-Ar), 109.9 5:1 to 1:1 to afford monomers 25, 26.
(CqAr-CN), 67.7 (CH2-O), 64.4 (CH2-OOC), 28.7 (CH2),
1-(phenoxymethyl)-4-vinylbenzene 25 [35]
28.3 (CH2), 22.5 (CH2), 18.2 (CH3). FTIR (NaCl, cm-1) ν 1.41 g, 63%
2227 (NC), ν 1711 (C=O), ν 1604 and 1494 (aromatic 1H RMN (400 MHz, CDCl3) δ ppm 7.41 (q, J = 8.21 Hz,
C=C), ν 1471(CH2), ν 1265 (C-O). White solid, mp 74- 4H, Ar-H), 7.28 (m, 2H, Ar-H), 6.96 (t, J = 8.39 Hz, 3H,
78ºC. Anal. Calcd for C22H23NO3: C, 75.62; H, 6.63; N, Ar-H), 6.72 (dd, J = 17.59, 10.89 Hz, 1H, CH=), 5.76
4.01. Found: C, 75.63; H, 6.62; N, 4.05.
(d, J = 17.59 Hz, 1H, =CH2a), 5.25 (d, J = 10.88 Hz,
5,5’-(1,4-phenylenebis(oxy))bis(pentane-5,1-diyl) 1H, =CH2b), 5.05 (s, 2H, CH2). 13C RMN (CDCl3) δ 158,7
bis(2-methylacrylate) 23
0.87 g, 85%
(CqAr-O), 136,5 (CqAr-C=), 136,4 (CqAr-CH2, CH=), 129,5
(C-Ar), 127,7 (C-Ar), 126,4 (C-Ar), 121,7 (C-Ar), 114,8
1H NMR (400 MHz, CDCl3) δ 6.81 (s, 4H, Ar-H), 6.10 (C-Ar), 114,0 (CH2=), 69,6 (CH2). FTIR (NaCl, cm-1)
(s, 2H, =CH2a), 5.55 (s, 2H, =CH2b), 4.20-4.14 (m, 4H, ν 1630 (CH2=C), ν 1600 and 1495 (aromatic C=C), ν
CH2-OOC), 3.94-3.89 (m, 4H, CH2-O), 1.94 (s, 6H, 1421 (CH2), ν 1379 (CH3), ν 1266 (C-O). White solid, mp
CH3), 1.84-1.70 (m, 8H, CH2), 1.60-1.53 (m, 4H, CH2). 109-114ºC. Anal. Calcd for C15H14O: C, 85.68; H, 6.71.
13C-RMN (CDCl3) δ 167.4 (C=O), 153.1 (CqAr-O), 136.5 Found: C, 85.66; H, 6.78.
(Cq=), 125.2 (CH2=), 115.4 (C-Ar), 68.3 (CH2-O), 64.5
1-(benzyloxymethyl)-4-vinylbenzene 26 [36]
(CH2-OOC), 29.0 (CH2), 28.4 (CH2), 22.6 (CH2), 18.3 1.33 g, 64%
(CH3). FTIR (NaCl, cm-1) ν 1716 (C=O), ν 1636 and 1508 1H NMR (400 MHz, CDCl3) δ ppm 7.40-7.28 (m, 9H,
(aromatic C=C), ν 1406 (CH2), ν 1165 (C-O). White oil. Ar-H), 6.70 (dd, J = 17.59, 10.88 Hz, 1H, CH=), 5.74
Anal. Calcd for C23H32O7: C, 68.87; H, 8.19. Found: C, (d, J = 17.59 Hz, 1H, =CH2a), 5.23 (d, J = 10.88 Hz, 1H,
68.80; H, 8.13.
5,5’-(biphenyl-2,2’-diylbis(oxy))bis(pentane-5,1- (CDCl3) δ 137,3 (CqAr-C), 136,1 (CqAr-C), 135,8 (CqAr-C),
=CH2b), 5.08 (s, 2H, CH2), 5.06 (s, 2H, CH2). 13C-RMN
diyl) bis(2-methylacrylate) 24
0.70 g, 68%
135.3 (CH=), 128,3 (C-Ar), 128,0 (C-Ar), 126,1 (C-Ar),
114,0 (CH2=), 66,0 (CH2), 65,7 (CH2). FTIR (NaCl, cm-1)
1H NMR (400 MHz, CDCl3) δ ppm 7.25 (dd, J = 15.18, ν 1631 and 1513 (aromatic C=C), ν 1631 (CH2=C), ν
7.40 Hz, 4H, Ar-H), 7.00-6.88 (m, 4H, Ar-H), 6.06 (s, 1454 (CH2), ν 1361 (C-O). Yellow oil. Anal. Calcd for
2H, =CH2a), 5.53 (s, 2H, =CH2b), 4.10-3.98 (m, 4H, CH2- C16H16O: C, 85.68; H, 7.19. Found: C,85.60; H, 7.26.
OOC), 3.90 (t, J = 6.21 Hz, 4H, CH2-O), 1.92 (s, 6H,
564

M. T. Barros et al.
4-(4-aminophenoxy)-N-(4-vinylbenzyl)
benzenamine 27
Supporting Information
0.43 g, 27%
Supporting information for this article, including
experimental procedures, characterization data and
copies of NMR and FTIR spectra of all products, is
available online.
1H NMR (400 MHz, CDCl3) δ ppm 7.38 (d, J = 7.99 Hz,
2H, Ar-H), 7.32 (d, J = 7.87 Hz, 2H, Ar-H), 6.81 (dd, J
= 12.76, 8.74 Hz, 4H, Ar-H), 6.70 (dd, J = 17.60, 10.90
Hz, 1H, CH=), 6.60 (dd, J = 17.39, 8.66 Hz, 4H, Ar-H),
5.73 (d, J = 17.60 Hz, 1H, =CH2a), 5.23 (d, J = 10.85
Hz, 1H, =CH2b), 4.27 (s, 2H, CH2). 13C-RMN (CDCl3) δ
ppm 150.8 (CqAr-O), 149.9 (CqAr-O), 143.8 (CqAr-N), 141.5
(CqAr-N), 139.0 (CqAr-N), 136.4 (CH=), 127.7 (C-Ar),
126.4 (C-Ar), 116.2 (CH2=), 113.9 (C-Ar), 113.7 (C-Ar),
48.7 (CH2). FTIR (NaCl, cm-1) ν 3053 (NH), δ 1504
(NH), γ 736 (NH), ν 1622 (aromatic C=C and CH2=C), ν
1407 (CH2). Brown solid, mp 100-105ºC. Anal. Calcd for
C30H28N2O: C, 79.72; H, 6.37; N, 8.85. Found: C, 79.72;
H, 6.30; N, 8.89.
Acknowledgment
This work has been supported by Fundação para a
Ciência e a Tecnologia (PTDC/CTM/69145/2006).
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