Synthesis and mesomorphic properties of esters derived from alkanediols

Article abstract of DOI:10.1134/S1070428007120068

New alkane-α,ω-diyl esters, propane-1,3-diyl and butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3-bromobenzoates], were synthesized and were found to form nematic mesophase. The effects of the lateral substituent and the length of the central and terminal hydrocarbon chains on the mesomorphic properties of butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3- bromobenzoates] were studied. Structural factors responsible for mesogenic properties of these compounds were determined by conformation analysis.

Full text of DOI:10.1134/S1070428007120068

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2007, Vol. 43, No. 12, pp. 1773–1780. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © S.I. Maksimenko, N.S. Novikova, R.V. Kondrat’eva, V.E. Kuz’min, L.N. Ognichenko, M.Yu. Yarkova, 2007, published in Zhurnal
Organicheskoi Khimii, 2007, Vol. 43, No. 12, pp. 1772–1779.
Synthesis and Mesomorphic Properties of Esters
Derived from Alkanediols
S. I. Maksimenko, N. S. Novikova, R. V. Kondrat’eva, V. E. Kuz’min,
L. N. Ognichenko, and M. Yu. Yarkova
Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine,
Lyustdorfskaya doroga 86, Odessa, 65080 Ukraine
e-mail: physchem@paco.net; nadyanovikova@rambler.ru
Received August 8, 2006
Abstract—New alkane-α,ω-diyl esters, propane-1,3-diyl and butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3-
bromobenzoates], were synthesized and were found to form nematic mesophase. The effects of the lateral
substituent and the length of the central and terminal hydrocarbon chains on the mesomorphic properties of
butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3-bromobenzoates] were studied. Structural factors responsible for
mesogenic properties of these compounds were determined by conformation analysis.
DOI: 10.1134/S1070428007120068
Liquid crystalline compounds with a bent structure
(so-called banana-shaped) find increasing applications
as components for LCD materials; therefore, studies on
the relations between the structure and liquid crystal-
line properties constitute an important problem. Most
compounds of this type contain five aromatic rings and
are either benzylideneimino derivatives or esters de-
rived from resorcinol, naphthalene-2,7-diol, or biphen-
yl-3,4′-diol and benzene-1,3-dicarboxylic acid [1–3].
In some cases, the central fragment was an alkane
chain rather than aromatic ring [1, 4]. Examples of
such structures are compounds Іa–Id which are called
twin mesogens or dimeric liquid crystals [4].
compounds having exclusively ester groups as bridg-
ing fragments. Taking into account empirical data for
liquid crystals [5], we anticipated to obtain molecular
structures favoring reduced mesophase temperature via
introduction of a lateral substituent into the aromatic
ring linked to the central aliphatic fragment.
Alkane-α,ω-diyl bis[4-(4-alkoxybenzoyloxy)-3-
bromobenzoates] VIII and IX were synthesized as
shown in Scheme 1. 3-Bromo-4-hydroxybenzoic acid
(V) prepared according to the known procedure [6]
was acylated with 4-alkoxybenzoyl chlorides in anhy-
drous pyridine. As intermediate compounds we isolat-
ed 4-(4-alkoxybenzoyloxy)-3-bromobenzoic acids
VIa–VIh [7] some of which (compounds VIa–VIc and
VIh) were not reported previously. The purity of acids
VIa–VIh was checked by thin-layer chromatography,
and their structure was proved by the 1H NMR data.
The lateral fragments of alkanediol esters І include
a C=N group; therefore, there is a necessity of separat-
ing mixtures of syn and anti isomers, and their phase
transition temperatures are fairly high. Aromatic car-
boxylic acid esters are free from the above disadvan-
tages; therefore, in the present work we synthesized
All (alkoxybenzoyloxy)benzoic acids VIa–VIh are
mesogenic: they give rise to nematic mesophase, and
O
O
O
O
N
N
AlkO
OAlk
Ia–Id
Alk = CnH2n + 1; n = 4, 7–9.
1773

MAKSIMENKO et al.
1774
Scheme 1.
COOH
COOH
COCl
SOCl2
COOH
AlkO
AlkO
O
IIa–IIh
IIIa–IIIh
Pyridine
+
O
Br
Br
COOH
AlkO
Br2
VIa–VIh
HO
HO
IV
V
O
7
COCl
(CH2)m
1
6
O
O
O
2
3
10
13
SOCl2
HO(CH2)mOH
9
11
12
5
8
O
O
4
Br
14
Br
AlkO
AlkO
2
VIIa, VIIb, VIId–VIIh
VIII, IXa–IXh
HO(CH2)3OH, DCC, DMAP
Alk = C6H13
VIc
Alk = CnH2n + 1; III, VI, VII, IX, n = 4 (a), 5 (b), 6 (c), 7 (d), 8 (e), 9 (f), 10 (g), 16 (h); VIII, m = 3, n = 9; IX, m = 4.
higher homolog VIh additionally has smectic phase.
The phase transition temperatures and types of meso-
phases of compounds VIa–VIh, determined by polar-
izing microscopy, are given in Table 1. Comparison of
the mesomorphic properties of 4-(4-alkoxybenzoyl-
oxy)-3-bromobenzoic acids VIa–VIh and their unsub-
stituted analogs [8] shows that the presence of a bulky
bromine atom reduces the phase transition temperature
to isotropic liquid.
Propane-1,3-diyl and butane-1,4-diyl bis[4-(4-alk-
oxybenzoyloxy)-3-bromobenzoates] VIII and IX were
synthesized by two methods: (1) direct reaction of
acids VI with the corresponding alkanediols in the
presence of N,N′-dicyclohexylcarbodiimide (DCC) and
4-dimethylaminopyridine (DMAP) in anhydrous
methylene chloride and (2) transformation of acids VI
into acid chlorides VII and subsequent acylation of
propane-1,3-diol and butane-1,4-diol in anhydrous
benzene. The first procedure includes only one step,
but the yields of the final products are poor, and their
purification is more difficult. Therefore, most syn-
theses were carried out according to the second two-
step procedure.
the structure was confirmed by 1H NMR spectroscopy.
Table 2 contains phase transition temperatures of bis-
esters VIII and IXa–IXh, determined by polarizing
microscopy. The data in Table 2 show that propane-
1,3-diyl bis[3-bromo-4-(4-nonyloxybenzoyloxy)ben-
zoate] (VIII) is not mesogenic and that extension of
the central hydrocarbon chain by one methylene group
gives rise to mesophase in the series of butane-1,4-diyl
bis[4-(4-alkoxybenzoyloxy)-3-bromobenzoates] IXa–
IXh. Compounds IX exhibit monotropic nematic
phase (the type of mesomorphism was determined ac-
cording to textures observed under polarized light).
Comparison of mesomorphic properties of bis-
esters VIII and IX and previously reported propane-
1,3-diyl [4-(4-alkoxybenzylideneimino)benzoates] Ia–
Id [4] having similar terminal substituents shows that
replacement of azomethine bridging group by ester
linker and introduction of an additional lateral substit-
uent (bromine atom) reduces the phase transition tem-
perature and changes the type of mesophase or even
eliminates mesogenic properties (compound VIII). In
order to interpret these data from the viewpoint of
molecular conformations, the structures of some com-
pounds were simulated using SPARTAN 04 program
implementing molecular-mechanics conformational
Compounds VIII and IX were purified by column
chromatography, their purity was checked by TLC, and
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007

SYNTHESIS AND MESOMORPHIC PROPERTIES OF ESTERS
1775
Table 1. Phase transition temperatures of 3-bromo-4-[4-alkoxybenzoyloxy]benzoic acids VIa–VIh
Phase transition temperature,a °C
Compound
no.
Cr
T1
Sm
T2
N
T3
I
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
142
0(72)
126
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
•
–
–
•
199.3
(d197.1)b
196.4
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
VIa
–
–
•
VIb
VIc
VId
VIe
VIf
–
0.0(85.2)
140
(194.6)
192.3
–
–
•
–
0(79)
121
(181.7)
186.0
–
–
•
–
0(99)
111
(186).0
173.0
–
–
•
–
0(93)
144
(173).0
183.0
–
–
•
–
(117)
117
(183).0
187.0
–
–
–
–
•
VIg
VIh
(104)
0.113.3
00.(97.4)
(186).0
161.4
–
•
110.6
•
(160.8)
a
Cr stands for crystalline phase, Sm for smectic phase, N for nematic phase, and I for isotropic liquid.
In parentheses are given the data for monotropic mesophase which is formed upon cooling the isotropic liquid.
b
search. Figures 1–3 show the most thermodynamically
stable conformations of molecules Id, VIII, and IXf
having nonyloxy groups as terminal substituents; the
strain energies are also given.
As follows from the results of calculations (Fig. 1),
the benzene rings adjacent to the central alkane frag-
ment in molecule Id are almost coplanar to each other.
The benzene rings bearing terminal substituents also
lie in parallel planes, thus forcing the terminal substit-
uents to adopt an extended shape. Such structure is
characterized by the minimal strain energy, and it dis-
plays the most ordered smectic mesophase (Table 2).
Mutual repulsion of the large bromine atoms in mole-
cule VIII (Fig. 2) distorts coplanar arrangement of
the aromatic rings adjacent to the central aliphatic
fragment, and replacement of the azomethine group by
Fig. 1. Calculated structure of propane-1,3-diyl bis[4-(4-nonyloxybenzylideneimino)benzoate] (Id); different projections are shown;
E = 87 kcal/mol.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007

MAKSIMENKO et al.
1776
Table 2. Phase transition temperatures of alkane-α,ω-diyl bis[4-(4-alkoxybenzoyloxy)-3-bromobenzoates VIII and IXa–IXh
and propane-1,3-diyl bis[4-(4-alkoxybenzylideneimino)benzoates] Ia–Id
Phase transition temperatures,a °C
Compound
no.
Cr
T1
Sm
T2
N
T3
I
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
072
122
–
–
–
–
–
•
–
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
VIII
IXa
–
–
0(57)
–
–
82.7)
100
–
–
–
•
–
IXb
IXc
IXd
IXe
IXf
00.(68.8)
108
–
–
81.7)
–
–
–
Mxb
–
•
–
0.0(66.0)
102
–
–
85).0
–
–
–
00.(64.8)
093
–
–
72.5)
–
–
–
•
–
0.0(74.4)
00.90.1
0(67)
–
–
89.5)
–
–
–
·
–
–
–
71.9)
0.068.9
0(30)
–
–
–
·
–
IXg
IXh
–
–
58.7)
077
–
–
–
–
·
–
00.(43.7)
142
–
60.7)
•
143
–
b(108)d
–
–
–
–
–
–
–
–
–
–
–
–
–
–
Ia
Ib
122
c
–
(•)
–
119
c
–
Ic
(•)
–
(104)
–
121
c
Id
(•)
(098)
a
b
c
d
For notations, see note a to Table 1.
Unidentified mesophase.
Crystallization temperatures were not given in [4].
In parentheses are given the data for monotropic mesophase which is formed upon cooling the isotropic liquid.
reference. The phase transition temperatures were
determined by polarizing microscopy using a POLAM
P-312 microscope. The purity of the products was
checked by TLC on Silufol UV-254 plates (detection
under UV light). Aluminum oxide L (5–40 μm) was
used for column chromatography (eluent benzene–
acetone, 10:1).
ester leads to flexure of the terminal fragments, so that
the molecule loses its rod-like shape and hence meso-
genic properties. Extension of the central hydrocarbon
bridge (Fig. 3) restores coplanar arrangement of the
adjacent aromatic rings, but orientation of the terminal
substituents implies that such molecular structure
could give rise to less ordered (than smectic) nematic
phase.
4-Alkoxybenzoyl chlorides IIIa–IIIh were syn-
thesized according to the procedure described in [9].
Compound IIIa: yield 83%, bp 130°C (2 mm), nD20
1.5487; IIIb: yield 95%, bp 140°C (2 mm), nD20
1.5422; IIIc: yield 91%, bp 190°C (3 mm), nD20
1.5370; IIId: yield 77.6%, bp 208°C (4 mm), nD20
1.5310; IIIe: yield 77.3%, bp 200°C (3 mm), nD20
=
=
=
=
=
EXPERIMENTAL
1
The H NMR spectra were measured from 5–10%
solutions on a Varian VXR-300 spectrometer
(300 MHz) relative to tetramethylsilane as internal
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007

SYNTHESIS AND MESOMORPHIC PROPERTIES OF ESTERS
1777
Fig. 2. Calculated structure of propane-1,3-diyl bis[3-bromo-4-(4-nonyloxybenzoyloxy)benzoate] (VIII); different projections are
shown; E = 134 kcal/mol.
Fig. 3. Calculated structure of butane-1,4-diyl bis[3-bromo-4-(4-nonyloxybenzoyloxy)benzoate] (IXd); different projections are
shown; E = 136 kkal/mol.
1.5281; IIIf: yield 78.3%, bp 220°C (3 mm), nD20
1.5246; IIIg: yield 87.9%, bp 200°C (3 mm), nD20
1.5234; IIIh; yield 95%, mp 50°C.
=
=
24 mmol of acid V in 30 ml of anhydrous pyridine, and
the mixture was stirred for 21 h at 20°C. It was then
poured into ice-cold water and acidified with hydro-
chloric acid to pH 2, the colorless crystalline solid was
filtered off, washed with water until neutral washings
(pH 7), dried, and dispersed in ~300 ml of cold alco-
hol, and the precipitate was filtered off and recrystal-
lized from benzene.
3-Bromo-4-hydroxybenzoic acid (V) was pre-
pared as described in [6]. Yield 65%, mp 178°C;
1
published data [6]: mp 177.5°C. H NMR spectrum
(CDCl3), δ, ppm: 7.09 d (1H, 5-H), 7.98–8.01 d.d (1H,
6-H), 8.26 d (1H, 2-H).
3-Bromo-4-(4-butoxybenzoyloxy)benzoic acid
(VIa). Yield 88%. 1H NMR spectrum (CDCl3), δ, ppm:
0.89 t (3H, CH3), 1.41–1.55 m (2H, CH3CH2), 1.76–
4-(4-Alkoxybenzoyloxy)-3-bromobenzoic acids
VIa–VIh (general procedure). Benzoyl chloride IIIa–
IIIh, 24 mmol, was added dropwise to a suspension of
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007

MAKSIMENKO et al.
1778
7.43 d (1H, C6H3), 8.11–8.13 d.d (1H, C6H3), 8.20 d
(2H, C6H4), 8.42 d (1H, C6H3).
1.89 m (2H, OCH2CH2), 4.06 t (2H, CH2O), 6.99 d
(2H, C6H4), 7.43 d (1H, C6H3), 8.11–8.13 d.d (1H,
C6H3), 8.20 d (2H, C6H4), 8.42 d (1H, C6H3). Found,
%: C 54.82; H 4.43; Br 20.18. C18H17BrO5. Calculated,
%: C 54.98; H 4.36; Br 20.32.
3-Bromo-4-(4-hexadecyloxybenzoyloxy)benzoic
acid (VIh). Yield 73%. 1H NMR spectrum (CDCl3), δ,
ppm: 0.88 t (3H, CH3), 1.18–1.41 m (24H, CH2), 1.42–
1.56 m (2H, OCH2CH2CH2), 1.74–1.92 m (2H,
OCH2CH2), 4.06 t (2H, CH2O), 7.00 d (2H, C6H4),
7.42 d (1H, C6H3), 8.11–8.13 d.d (1H, C6H3), 8.19 d
(2H, C6H4), 8.42 d (1H, C6H3). Found, %: C 64.27;
H 7.20; Br 14.27. C30H41BrO5. Calculated, %: C 64.17;
H 7.36; Br 14.23.
3-Bromo-4-(4-pentyloxybenzoyloxy)benzoic acid
(VIb). Yield 71%. 1H NMR spectrum (CDCl3), δ, ppm:
0.89 t (3H, CH3), 1.15–1.41 m (2H, CH2), 1.41–1.55 m
(2H, CH3CH2CH2), 1.76–1.89 m (2H, OCH2CH2),
4.06 t (2H, OCH2), 6.99 d (2H, C6H4), 7.43 d (1H,
C6H3), 8.11–8.13 d.d (1H, C6H3), 8.20 d (2H, C6H4),
8.42 d (1H, C6H3). Found, %: C 56.09; H 4.86;
Br 19.45. C19H19BrO5. Calculated, %: C 56.03; H 4.70;
Br 19.62.
4-(4-Alkoxybenzoyloxy)-3-bromobenzoyl chlo-
rides VIIa–VIIh (general procedure). Thionyl chlo-
ride, 14.8 mmol, was added over a period of 30 min
under stirring and cooling to a solution of 4.2 mmol of
acid VIa–VIh in 20 ml of anhydrous benzene. The
mixture was then heated for 9 h under reflux on
a water bath, the solvent and excess thionyl chloride
were distilled off under reduced pressure, 15 ml of
anhydrous benzene was added to the residue, and the
solvent was distilled off under reduced pressure. The
products were used in further syntheses without addi-
tional purification.
3-Bromo-4-(4-hexyloxybenzoyloxy)benzoic acid
(VIc). Yield 67%. 1H NMR spectrum (CDCl3), δ, ppm:
0.88 t (3H, CH3), 1.15–1.40 m (4H, CH2), 1.41–1.56 m
[2H, CH2(CH2)2O], 1.76–1.89 m (2H, CH2CH2O),
4.06 t (2H, CH2O), 7.00 d (2H, C6H4), 7.43 d (1H,
C6H3), 8.12–8.14 d.d (1H, C6H3), 8.20 d (2H, C6H4),
8.42 d (1H, C6H3). Found, %: C 56.77; H 4.89;
Br 18.81. C20H21BrO5. Calculated, %: C 57.02; H 5.02;
Br 18.97.
3-Bromo-4-(4-heptyloxybenzoyloxy)benzoic acid
(VId) [7]. Yield 57%. H NMR spectrum (CDCl3), δ,
Propane-1,3-diyl [3-bromo-4-(4-nonyloxy-
benzoyloxy)benzoate] (VIII). Triethylamine, 1 ml,
was added to a solution of 2.08 g (4.2 mmol) of
benzoyl chloride VIIf in 15 ml of anhydrous benzene,
0.189 g (2.1 mmol) of propane-1,3-diol was added on
cooling, and the mixture was stirred for 15 h at 25°C,
the progress of the reaction being monitored by TLC.
The mixture was poured onto crushed ice and extracted
with chloroform (2 × 20 ml), and the extract was dried
over anhydrous magnesium sulfate, filtered from the
drying agent, and evaporated under reduced pressure.
The residue, a dark yellow oily substance, was washed
with ethanol (3 × 30 ml). Yield 1.2 g (19%), off-white
1
ppm: 0.88 t (3H, CH3), 1.15–1.40 m (6H, CH2), 1.41–
1.56 m (2H, OCH2CH2CH2), 1.77–1.89 m (2H,
OCH2CH2), 4.06 t (2H, OCH2), 7.00 d (2H, C6H4),
7.43 d (1H, C6H3), 8.12–8.14 d.d (1H, C6H3), 8.20 d
(2H, C6H4), 8.42 d (1H, C6H3).
3-Bromo-4-(4-octyloxybenzoyloxy)benzoic acid
1
(VIe) [7]. Yield 77%. H NMR spectrum (CDCl3), δ,
ppm: 0.89 t (3H, CH3), 1.16–1.40 m (8H, CH2), 1.41–
1.56 m (2H, OCH2CH2CH2), 1.75–1.89 m (2H,
OCH2CH2), 4.06 t (2H, OCH2), 7.00 d (2H, C6H4),
7.43 d (1H, C6H3), 8.11–8.13 d.d (1H, C6H3), 8.20 d
(2H, C6H4), 8.42 d (1H, C6H3).
1
powder. H NMR spectrum (CDCl3), δ, ppm: 0.89 t
(6H, CH3, J = 6.53 Hz), 1.29–1.61 m (24H, CH2),
1.78–1.87 m (4H, OCH2CH2), 2.22–2.35 m (2H,
OCH2CH2CH2O), 4.05 t (4H, OCH2, J = 6.53 Hz),
4.43 s (4H, OCH2CH2CH2O), 6.98 d (4H, 11-H, 13-H,
J = 9.02 Hz), 7.37 d (2H, 6-H, J = 8.09 Hz), 8.04–
8.07 d.d (2H, 7-H, J1 = 8.4, J2 = 1.87 Hz), 8.17 d
(4H, 10-H, 14-H, J = 9.02 Hz), 8.34 d (2H, 3-H, J =
1.86 Hz). Found, %: C 60.68; H 5.91; Br 16.38.
C49H58Br2O10. Calculated, %: C 60.87; H 6.05;
Br 16.53.
3-Bromo-4-(4-nonyloxybenzoyloxy)benzoic acid
(VIf) [7]. Yield 64%. H NMR spectrum (CDCl3), δ,
ppm: 0.89 t (3H, CH3), 1.19–1.41 m (10H, CH2), 1.41–
1.55 m (2H, OCH2CH2CH2), 1.77–1.89 m (2H,
OCH2CH2), 4.06 t (2H, OCH2), 6.99 d (2H, C6H4),
7.43 d (1H, C6H3), 8.12-8.14 d.d (1H, C6H3), 8.20 d
(2H, C6H4), 8.42 d (1H, C6H3).
1
3-Bromo-4-(4-decyloxybenzoyloxy)benzoic acid
1
(VIg) [7]. Yield 46%. H NMR spectrum (CDCl3), δ,
ppm: 0.89 t (3H, CH3), 1.15–1.41 m (12H, CH2), 1.41–
1.55 m (2H, OCH2CH2CH2), 1.76–1.89 m (2H,
OCH2CH2), 4.06 t (2H, OCH2), 6.99 d (2H, C6H4),
Compounds IXa, IXb, and IXd–IXh were synthe-
sized in a similar way.
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SYNTHESIS AND MESOMORPHIC PROPERTIES OF ESTERS
1779
7.37 d (2H, 6-H, J = 8.41 Hz), 8.04–8.07 d.d (2H, 7-H,
J1 = 8.4, J2 = 1.86 Hz), 8.17 d (4H, 10-H, 14-H, J =
8.72 Hz), 8.33 d (2H, 3-H, J = 1.87 Hz). Found, %:
C 60.32; H 6.02; Br 16.77. C48H56Br2O10. Calculated,
%: C 60.51; H 5.92; Br 16.77.
Butane-1,4-diyl bis[3-bromo-4-(4-butoxyben-
zoyloxy)benzoate] (IXa) was obtained from 2 g
(9.4 mmol) of compound VIIa and 0.423 g (4.7 mmol)
1
of butane-1,4-diol. Yield 1.5 g (38%). H NMR spec-
trum (CDCl3), δ, ppm: 0.89 t (6H, CH3, J = 6.53 Hz),
1.28–1.53 m (4H, CH2), 1.78–1.87 m (4H, OCH2CH2),
1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t (4H, OCH2,
J = 6.53 Hz), 4.43 s [4H, OCH2(CH2)2CH2O], 6.98 d
(4H, 11-H, 13-H, J = 9.02 Hz), 7.37 d (2H, 6-H, J =
8.09 Hz), 8.04–8.07 d.d (2H, 7-H, J1 = 8.4, J2 =
1.87 Hz), 8.17 d (4H, 10-H, 14-H, J = 9.02 Hz), 8.33 d
(2H, 3-H, J = 1.86 Hz). Found, %: C 57.35; H 4.60;
Br 19.08. C40H40Br2O10. Calculated, %: C 57.16;
H 4.80; Br 19.01.
Butane-1,4-diyl bis[3-bromo-4-(4-nonyloxyben-
zoyloxy)benzoate] (IXf) was obtained from 3.65 g
(7.6 mmol) of compound VIIf and 0.34 g (3.8 mmol)
1
of butane-1,4-diol. Yield 0.4 g (11%). H NMR spec-
trum (CDCl3), δ, ppm: 0.89 t (6H, CH3, J = 6.53 Hz),
1.29–1.61 m (24H, CH2), 1.78–1.87 m (4H, OCH2CH2),
1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t (4H, OCH2,
J = 6.53 Hz), 4.43 s (4H), 6.98 d (4H, 11-H, 13-H, J =
8.71 Hz), 7.37 d (2H, 6-H, J = 8.09 Hz), 8.04–8.07 d.d
(2H, 7-H, J1 = 8.4, J2 = 1.56 Hz), 8.17 d (4H, 10-H,
14-H, J = 8.71 Hz), 8.34 d (2H, 3-H, J = 1.24 Hz).
Found, %: C 61.09; H 6.34; Br 16.36. C50H60Br2O10.
Calculated, %: C 61.23; H 6.17; Br 16.29.
Butane-1,4-diyl bis[3-bromo-4-(4-pentyloxyben-
zoyloxy)benzoate] (IXb) was obtained from 3.15 g
(7.4 mmol) of compound VIIb and 0.33 g (3.7 mmol)
1
of butane-1,4-diol. Yield 0.683 g (21%). H NMR
spectrum (CDCl3), δ, ppm: 0.89 t (6H, CH3, J =
6.53 Hz), 1.29–1.61 m (8H, CH2), 1.78–1.87 m (4H,
OCH2CH2), 1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t
(4H, OCH2, J = 6.53 Hz), 4.43 s [4H, OCH2(CH2)2-
CH2O], 6.98 d (4H, 11-H, 13-H, J = 9.02 Hz), 7.37 d
(2H, 6-H, J = 8.09 Hz), 8.04–8.07 d.d (2H, 7-H, J1 =
8.4, J2 = 1.87 Hz), 8.17 d (4H, 10-H, 14-H, J =
9.02 Hz), 8.34 d (2H, 3-H, J = 1.86 Hz). Found, %:
C 57.87; H 5.26; Br 18.33. C42H44Br2O10. Calculated,
%: C 58.08; H 5.11; Br 18.40.
Butane-1,4-diyl bis[3-bromo-4-(4-heptyloxyben-
zoyloxy)benzoate] (IXd) was obtained from 2.09 g
(4.6 mmol) of compound VIId and 0.207 g (2.3 mmol)
of butane-1,4-diol. Yield 0.297 g (14%). 1H NMR spec-
trum (CDCl3), δ, ppm: 0.90 t (6H, CH3, J = 6.53 Hz),
1.23–1.54 m (16H, CH2), 1.75–1.90 m (4H, OCH2CH2),
1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t (4H, OCH2,
J = 6.53 Hz), 4.43 s [4H, OCH2(CH2)2CH2O], 6.98 d
(4H, 11-H, 13-H, J = 9.02 Hz), 7.37 d (2H, 6-H, J =
8.09 Hz), 8.04–8.07 d.d (2H, 7-H, J1 = 8.4, J2 =
1.87 Hz), 8.17 d (4H, 10-H, 14-H, J = 9.02 Hz), 8.33 d
(2H, 3-H, J = 1.86 Hz). Found, %: C 59.91; H 5.55;
Br 17.50. C46H52Br2O10. Calculated, %: C 59.75;
H 5.67; Br 17.28.
Butane-1,4-diyl bis[3-bromo-4-(4-decyloxyben-
zoyloxy)benzoate] (IXg) was obtained from 3.12 g
(6.5 mmol) of compound VIIg and 0.25 g (3.3 mmol)
1
of butane-1,4-diol. Yield 0.3 g (14%). H NMR spec-
trum (CDCl3), δ, ppm: 0.89 t (6H, CH3, J = 6.53 Hz),
1.28–1.53 m (28H, CH2), 1.78–1.87 m (4H, OCH2CH2),
1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t (4H, OCH2,
J = 6.53 Hz), 4.43 s [4H, OCH2(CH2)2CH2O], 6.98 d
(4H, 11-H, 13-H, J = 8.71 Hz), 7.37 d (2H, 6-H, J =
8.09 Hz), 8.04–8.07 d.d (2H, 7-H, J1 = 8.4, J2 =
1.56 Hz), 8.17 d (4H, 10-H, 14-H, J = 8.71 Hz), 8.33 d
(2H, 3-H, J = 1.24 Hz). Found, %: C 61.87; H 6.34;
Br 16.94. C52H64Br2O10. Calculated, %: C 61.91;
H 6.39; Br 15.84.
Butane-1,4-diyl bis[3-bromo-4-(4-hexadecyloxy-
benzoyloxy)benzoate] (IXh) was obtained from 2.09 g
(3.6 mmol) of compound VIIh and 0.162 g (1.8 mmol)
of butane-1,4-diol. Yield 0.213 g (10%). 1H NMR spec-
trum (CDCl3), δ, ppm: 0.89 t (6H, CH3, J = 6.53 Hz),
1.28–1.64 m (4H, CH2), 1.78–1.87 m (4H, OCH2CH2),
1.96 br.s [4H, OCH2(CH2)2CH2O], 4.05 t (4H, OCH2,
J = 6.53 Hz), 4.43 s [4H, OCH2(CH2)2CH2O], 6.98 d
(4H, 11-H, 13-H, J = 8.71 Hz), 7.37 d (2H, 6-H, J =
8.09 Hz), 8.04–8.07 d.d (2H, 7-H, J1 = 8.4, J2 =
1.56 Hz), 8.17 d (4H, 10-H, 14-H, J = 8.71 Hz), 8.34 d
(2H, 3-H, J = 1.24 Hz). Found, %: C 65.20; H 7.44;
Br 13.49. C64H88Br2O10. Calculated, %: C 65.30;
H 7.54; Br 13.58.
Butane-1,4-diyl bis[3-bromo-4-(4-octyloxyben-
zoyloxy)benzoate] (IXe) was obtained from 2.1 g
(4.5 mmol) of compound VIIe and 0.203 g
(2.25 mmol) of butane-1,4-diol. Yield 0.218 g (10%).
1H NMR spectrum (CDCl3), δ, ppm: 0.90 t (6H, CH3,
J = 6.23 Hz), 1.30–1.50 m (20H, CH2), 1.78–1.87 m
(4H, OCH2CH2), 1.96 br.s [4H, OCH2(CH2)2CH2O],
4.05 t (4H, OCH2, J = 6.54 Hz), 4.43 s [4H, OCH2-
(CH2)2CH2O], 6.98 d (4H, 11-H, 13-H, J = 8.72 Hz),
Butane-1,4-diyl bis[3-bromo-4-(4-hexyloxyben-
zoyloxy)benzoate] (IXc). A mixture of 2 g (4.8 mmol)
of 3-bromo-4-(4-hexyloxybenzoyloxy)benzoic acid
(VIc), 0.096 g (0.48 mmol) of 4-dimethylamino-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007

MAKSIMENKO et al.
1780
pyridine, and 0.216 g (2.4 mmol) of butane-1,4-diol in
20 ml of anhydrous methylene chloride was stirred for
10 min, 0.988 g (4.8 mmol) of N,N′-dicyclohexyl-
carbodiimide was added, and the mixture was stirred
for 16 h at room temperature. When the reaction was
complete (TLC), the precipitate was filtered off, and
the filtrate was diluted with 30 ml of methylene
chloride, washed in succession with a 5% solution of
acetic acid (2 × 50ml), 5% aqueous sodium hydroxide
(2×25 ml), and water (3×25 ml) to pH 7, and dried
over anhydrous magnesium sulfate. The solvent was
distilled off under reduced pressure, and the residue
was recrystallized from hexane–diethyl ether (1:3) and
additionally purified by column chromatography. Yield
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0.097 g (5%). H NMR spectrum (CDCl3), δ, ppm:
p. 2556.
0.89 t (6H, CH3, J = 6.53 Hz), 1.29–1.61 m (12H,
CH2), 1.78–1.87 m (4H, OCH2CH2), 1.96 br.s [4H,
OCH2(CH2)2CH2O], 4.05 t (4H, OCH2, J = 6.53 Hz),
4.43 s [4H, OCH2(CH2)2CH2O], 6.98 d (4H, 11-H,
13-H, J = 8.71 Hz), 7.37 d (2H, 6-H, J = 8.09 Hz),
8.04–8.07 d.d (2H, 7-H, J1 = 8.4, J2 = 1.56Hz), 8.17 d
(4H, 10-H, 14-H, J = 8.71 Hz), 8.34 d (2H, 3-H, J =
1.24 Hz). Found, %: C 58.93; H 5.20; Br 17.80.
C44H48Br2O10. Calculated, %: C 58.94; H 5.40;
Br 17.82.
7. Novіkova, N.S. Kіlіmenchuk, O.D., Kondrat’’єva, R.V.,
and Derkach, L.G., Ukr. Patent no. 5633, 2005; Byull.
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Khim. Geterotsikl. Soedin., 1991, p. 386.
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007