Development of a new traceless aniline linker for solid-phase synthesis of azomethines. Application to parallel synthesis of a rod-shaped liquid crystalline library

Article abstract of DOI:10.1016/j.tet.2005.08.086

A new traceless linker was developed to synthesize a library of 42 compounds possessing an azomethine linkage using combinatorial solid-phase parallel synthesis. The loading of the substrates on a solid support and cleavage from the solid support were performed by an imine synthesis and by imine-exchanged process under mild conditions, respectively. Thioesters with a hydroxy group on the central core exhibited liquid crystalline properties with the widest transition temperatures in the library.

Full text of DOI:10.1016/j.tet.2005.08.086

Tetrahedron 61 (2005) 10643–10651
Development of a new traceless aniline linker for solid-phase
synthesis of azomethines. Application to parallel synthesis
of a rod-shaped liquid crystalline library
a
a
a
a
Hideaki Hioki,a, Mizuki Fukutaka, Hideki Takahashi, Miwa Kubo, Kimihito Matsushita,
*
Mitsuaki Kodama,a Kanji Kubo,b Keiko Idetab and Akira Morib,
*
aFaculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
bInstitute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
Received 20 July 2005; revised 20 August 2005; accepted 22 August 2005
Available online 19 September 2005
Abstract—A new traceless linker was developed to synthesize a library of 42 compounds possessing an azomethine linkage using
combinatorial solid-phase parallel synthesis. The loading of the substrates on a solid support and cleavage from the solid support were
performed by an imine synthesis and by imine-exchanged process under mild conditions, respectively. Thioesters with a hydroxy group on
the central core exhibited liquid crystalline properties with the widest transition temperatures in the library.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
traceless linker to synthesize rod-shaped azomethine
derivatives,7 which are typical liquid crystals.8
Solid-phase organic synthesis has been commonly used for
combinatorial synthesis to rapidly discover new drugs and
materials. Many types of linkers were recently developed in
combinatorial solid-phase syntheses because the selection
of an adequate linker is important to efficiently build the
desired libraries.1 Linkers should be easy to load starting
materials onto the solid support, must be stable during the
reactions and must be cleavable without damage to the
product at the final stage. Especially, traceless linkers have
advantages because the point of attachment on the solid
support is not apparent in the target molecules.2
2. Results and discussion
2.1. Development of a new aniline linker and synthesis of
a liquid crystalline library
The structure of the target molecules 1 synthesized on the
Liquid crystals are widely used in optoelectric devices and
electron-transporting materials. Considerable synthetic
effort and time are required to develop new liquid crystals.
We previously demonstrated an efficient combinatorial
synthesis to search for new liquid crystals and to system-
atically investigate the substitution effect on mesomorphism
by preparing liquid crystalline libraries on a solid support.3–6
In this paper, we focus on the development of a new
Keywords: Liquid crystals; Combinatorial synthesis; Traceless linker;
Azomethines.
*
Corresponding authors. Tel.:C81 88 622 9611; fax: C81 88 655 3051
(H.H.); tel.:C81 92 583 7806; fax: C81 92 583 7810 (A.M.); e-mail
addresses: hioki@ph.bunri-u.ac.jp; mori-a@cm.kyushu-u.ac.jp
Scheme 1. Synthetic plan of an azomethine-type liquid crystalline library.
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.08.086

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H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
solid phase is shown in Scheme 1. They are composed of a
rigid aromatic core with an azomethine linkage, an alkoxy
side chain, and an ester or amide group. We planned to
construct a liquid crystalline library through solid-phase
synthesis by employing imine-exchange reactions9 because
the target molecules 1 have no extra functional groups to
attach to the solid support. In addition, because the
azomethine linkage is labile to acids and bases, we designed
a new linker suitable for synthesizing the liquid crystals
with an azomethine linkage on a solid support under mild
conditions. In the first step, l members of 4-formylbenzoic
acids 2 are condensed with an amine 3 on the solid support
to afford resin-bound azomethine 4 (step 1). In the second
step, m members of alcohols, thiols, and amines 5 are
reacted with 4 to give azomethine 6 (step 2). Finally, the
azomethines on the solid support are cleaved by n members
of 4-alkoxyanilines 7 through an imine-exchange process to
give 1 (step 3). In the consecutive procedure, l!m!n
members of compounds are synthesized in these three steps.
reaction, which gave the desired product 10 in only 16%
yield due to the instability of resin-bound azomethine 9. To
stabilize the resin-bound azomethine, we synthesized a
linker 11 from 8 and a 4-aminobenzoic acid derivative. The
loading of methyl 4-formylbenzoate and cleavage with
4-octyloxyaniline on the resin 12 gave the azomethine 10 in
75% yield. A three-step procedure involving 4-formyl-
benzoic acid loading followed by condensation with
1-nonanol and cleavage with 4-octyloxyaniline afforded
14aa8 in 47% yield. This reduced yield might result from
partial alcoholysis of a resin-bound azomethine 13 during
the condensation step. (Scheme 2)
4-Alkoxyaniline linker 15 was synthesized to stabilize a
resin-bound azomethine intermediate. Simple loading and
cleavage using 15 gave the desired product 10 in 70% yield.
The equilibrium between 10 and 16 was not shifted
effectively in favor of 10 due to their comparable stability
even addition of 4 equiv of 4-octyloxyaniline. (Scheme 3)
Methyl 4-formylbenzoate was linked to aminomethylated
SynPhase Lantern 8, a multipin solid support, through imine
formation to give resin-bound methyl benzoate 9. 4-Octyl-
oxyaniline was added to proceed to the imine-exchange
The product yields were dependent on the delicate stability
balance of the resin-bound azomethine. The ideal linker
should resist alcoholysis during condensation and cause an
equilibrium shift favorable to the product in the final step.
Scheme 2. Model synthesis of azomethines on a solid support from 8 or 11. Reaction conditions: (a) methyl 4-formylbenzoate, DMF, rt, 24 h;
(b) 4-octyloxyaniline, 50 8C, 3 h; (c) 4-tert-butoxycarbonylaminobenzoic acid, DIC, HOBt, DCM, then TFA, DCM; (d) 4-formylbenzoic acid, DMF, rt, 24 h;
(e) 1-nonanol, DIC, DMAP, DCM, rt, 3 h.
Scheme 3. Model synthesis of azomethine 10 on a solid support using an aniline linker 15. Reaction conditions: (a) 6-(4-tert-butoxycarbonylaminophenoxyl)-
hexanoic acid, DIC, HOBt, DCM, then TFA, DCM; (b) methyl 4-formylbenzoate, DMF, rt, 24 h; (c) 4-octyloxyaniline, 50 8C, 3 h.

H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
10645
Scheme 4. Model synthesis of azomethines on a solid support using an aniline linker 17. Reaction conditions: (a) 4-(4-tert-butoxycarbonylaminophenyl)-
butyric acid, DIC, HOBt, DCM, then TFA, DCM; (b) methyl 4-formylbenzoate, DMF, rt, 24 h; (c) 4-octyloxyaniline, 50 8C, 3 h; (d) 4-formylbenzoic acid,
DMF, rt, 24 h; (e) 1-nonanol, DIC, DMAP, DCM, rt, 3 h.
Scheme 5. Partial alcoholysis and subsequent condensation in the second step.
Scheme 6. Parallel synthesis of an azomethine library on a solid support. Reaction conditions: (a) 2 kinds of 4-formylbenzoic acid (4-formylbenzoic acid,
4-formyl-3-hydroxybenzoic acid), DMF, rt, 24 h; (b) 4 kinds of alcohols, thiol, and amine (n-C9H19OH, Et(OC2H4)2OH, n-C9H19SH, (Me2CHCH2)2NH), DIC,
DMAP, DCM, rt, 3 h; (c) 7 kinds of 4-alkoxyanilines (nZ4–10), DMF, 50 8C, 24 h.

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H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
Finally, 4-alkylaniline linker 17 was investigated. (Scheme
4) The resin-bound intermediate 18 was expected to have
moderate stability between 12 and 16. The product 10 was
obtained in 94% yield by simple loading and cleavage. The
three-step procedure involving condensation with 1-nonanol
gave 14aa8 in 66% yield.
2.2. Library synthesis of rod-shaped liquid crystals
The linker 17 was most suitable for the synthesis of
azomethines on the solid support in our experiment. We
applied the linker 17 to parallel synthesis of a rod-shaped
liquid crystalline library shown in Scheme 6. 4-Formyl-
benzoic acid and 4-formyl-3-hydroxybenzoic acid were
linked to 17 to afford two members of resin-supported
azomethines 19a and 19b. The reaction of 19a with two
alcohols, a thiol, and an amine gave the corresponding esters
22aa, 22ab, a thioester 22ac and an amide 22ad. On the
other hand, 19b was reacted with an alcohol and a thiol to
form an ester 22ba and a thioester 22bc. Finally, all six
members of azomethines are reacted with 7 kinds of
4-alkoxyanilines to afford the 42 final products through
imine-exchange reactions. Esters 14aa4–14aa10 (nZ4–10)
and 14ab4–14ab10 (nZ4–10) and thioesters 14ac4–14ac10
(nZ4–10) were obtained in moderate yield after chromato-
graphic purification (Table 1). On the other hand, amides
14ad4–14ad10 (nZ4–10) were obtained in low yield,
Because the original linker 17 must be recovered after
cleavage of the resin-bound azomethines, we investigated
the possibility of recycling of the linker 17. In the case of
simple loading and cleavage, the yield of the repeated using
was comparable to the first one. However, the yield
decreased considerably from 66 to 40% for the recycling
in the three-step procedure. (Scheme 4) To elucidate the
details of the reaction occurred on the resin, the recycled
resin was treated with methyl 4-formylbenzoate. The
methylester 10 was obtained in 15% yield. This result
indicates that azomethine 21 was partially formed on the
solid support via alcoholysis of 19a and consecutive
condensation in the second step. (Scheme 5).
Table 1. Isolated yields and transition temperatures of all library members
Compounds
X
H
R
n
Yield (%)
Transition temperatures (8C) and enthalpy changes (kJ molK1 a
)
14aa4
14aa5
14aa6
14aa7
14aa8
14aa9
14aa10
14ab4
14ab5
14ab6
14ab7
14ab8
14ab9
14ab10
14ac4
14ac5
14ac6
14ac7
14ac8
14ac9
14ac10
14ad4
14ad5
14ad6
14ad7
14ad8
14ad9
14ad10
14ba4
14ba5
14ba6
14ba7
14ba8
14ba9
14ba10
14bc4
14bc5
14bc6
14bc7
14bc8
14bc9
14bc10
OC9H19
4
5
55
58
Cr 58.7 (25.2) SmA 81.3 (3.3) Iso
Cr 58.1 (27.0) SmA 76.0 (3.0) Iso
6
7
8
9
10
4
5
6
7
8
9
10
4
5
6
7
8
9
10
4
5
6
7
8
9
10
4
5
6
7
8
9
10
4
5
6
7
59
57
66
58
55
71
53
57
58
52
51
60
53
58
82
52
53
33
33
25
12
18
16
20
22
24
47
46
52
50
47
43
Cr 57.8 (27.6) SmA 84.3 (3.8) Iso
Cr 65.1 (30.4) SmA 84.4 (3.8) Iso
Cr 63.7 (28.1) SmA 88.3 (3.9) Iso
Cr1 67.8 (12.4) Cr2 70.4 (15.8) SmC 85.7 SmA 87.6 (4.2) Iso
Cr 75.1 (17.3) SmC 80.7 SmA 89.6 (4.4) Iso
Cr 74.2 (32.2) [SmA 42.8 (3.1)] Isob
Cr 57.0 (27.5) [SmA 27.5 (2.4)] Iso
Cr 62.2 (31.1) [SmA 40.3 (3.2)] Iso
Cr 43.5 (23.0) [SmA 38.8 (3.0)] Iso
Cr1 40.0 (5.3) Cr2 43.5 (15.3) SmA 46.7 (3.9) Iso
Cr 58.4 (28.6) Iso
Cr 56.9 (28.0) Iso
Cr 78.3 (16.7) SmF 82.9 (0.8) SmA 150.8 (3.5) Iso
Cr 72.8 (21.8) SmF 83.4 (1.1) SmC 100.5 SmA 148.5 (3.5) Iso
Cr 70.2 (14.7) SmF 92.7 (1.6) SmC 111.2 SmA 149.8 (4.3) Iso
Cr 75.1 (23.2) SmF 95.2 (1.8) SmC 131.0 SmA 147.8 (4.4) Iso
Cr 76.9 (19.1) SmF 102.4 (2.3) SmC 133.7 SmA 148.7 (4.3) Iso
Cr 87.1 (24.4) SmF 102.6 (2.9) SmC 137.4 SmA 143.5 (4.3) Iso
Cr 90.0 (22.7) SmF 106.6 (3.4) SmC 142.6 SmA 146.1 (5.8) Iso
Cr 98.7 Iso
Cr 72.7 Iso
Cr 83.3 Iso
Cr 85.2 Iso
Cr 105.5 Iso
Cr 93.4 Iso
Cr 78.5 Iso
Cr 70.6 (19.8) SmA 128.7 (4.2) Iso
Cr 73.2 (21.3) SmA 123.8 (4.2) Iso
Cr 77.0 (18.3) SmA 126.7 (4.7) Iso
Cr 76.0 (23.3) SmC 81.0 SmA 124.0 (4.8) Iso
Cr 85.7 (25.4) SmC 99.0 SmA 125.0 (5.0) Iso
Cr 92.0 (27.1) SmC 113.0 (0.2) SmA 123.7 (4.6) Iso
Cr 85.1 (31.6) SmC 118.2 (0.1) SmA 124.3 (5.4) Iso
Cr1 47.8 (1.3) Cr2 62.7 (8.2) SmA 188.1 (4.4) Iso
Cr 68.6 (13.6) SmA 185.2 (5.3) Iso
Cr1 55.9 (3.3) Cr2 58.7 (8.8) SmA 185.7 (5.2) Iso
Cr 60.1 (11.2) SmC 149.0 SmA 182.5 (5.5) Iso
Cr 64.7 (12.5) SmC 161.0 SmA 182.1 (5.6) Iso
Cr 71.2 (14.3) SmC 171.0 (0.2) SmA 178.6 (6.1) Iso
Cr 70.7 (16.1) SmC 173.5 (0.2) SmA 177.6 (6.4) Iso
H
O(C2H4O)2Et
H
SC9H19
H
N(CH2CHMe2)2
OH
OH
OC9H19
30
SC9H19
17 (38)c
20 (38)
18 (40)
21 (39)
19 (40)
20 (32)
17 (34)
8
9
10
a The transition temperatures and the enthalpy changes shown in parentheses were determined by the second heating of DSC except for 14ad series. The
transition temperatures of 14ad series were determined by the second heating of optical microscopy.
b Mesomorphic phases, transition temperatures and enthalpy changes in brackets were observed in the first cooling process.
c Values in parentheses refer to yields for 16 equiv of 1-nonanethiol in step 2.

H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
10647
possibly because the imine-exchange reaction between 19a
3. Conclusion
and diisobutylamine partially occurs at the second step. The
yields of 14b series (XZOH) were lower than correspond-
ing 14a series (XZH) probably due to partial self-
condensation between a phenolic hydroxy and carboxylic
group in 19b on the resin. Addition of large excess
(16 equiv) of thiol at the second step improved the yield
in 14bc series.
We developed a new traceless linker, which made it possible
to synthesize a library of liquid crystals with an azomethine
linkage using imine-exchange reactions through combina-
torial solid-phase parallel syntheses. This linker has the
advantage of being able to release the final product under
mild conditions. Thioesters at the terminal position with
hydroxy group on the central core exhibited smectic phases
with the widest transition temperatures in the library
consisting of 42 members. Thermal stability of the library
members was explained by consideration of the linearity
and planarity of the molecules and flexibility and bulkiness
of the substituents of the ester and the amide groups.
2.3. Mesomorphic behavior
The transition temperature and the thermal behavior of the
library members were determined using a polarizing
microscope equipped with a hot stage and differential
scanning calorimetry (DSC) measurement. The results are
summarized in Table 1. Esters 14aa4–14aa10 (nZ4–10)
exhibited smectic A (SmA) and C (SmC) phases, in which
the SmA phase was demonstrated by observation of fan and
homeotropic textures while the SmC phase was assigned by
observation of fan and schlieren textures. The X-ray
diffraction study of 14aa10 (nZ10) indicated that the
4. Experimental
4.1. General
All commercially available chemicals were used without
further purification except 4-alkoxyanilines. The 4-alkoxy-
anilines were further purified by recrystallization. The
SynPhase Lantern 8 was purchased from Mimotopes Pty
Ltd (Victoria, Australia). Melting points were determined
using a Bu¨chi B-545 apparatus and are uncorrected. IR
spectra were recorded with a JASCO FT/IR410 spectro-
photometer equipped with SensIR Technologies Dura-
scopee for ATR (attenuated total reflectance) and only
˚
layer spacings of the SmA and SmC phases were 34.3 A at
˚
87 8C and 33.8 A at 78 8C, respectively. Because the
˚
calculated molecular length of 14aa10 (nZ10) is 37.1 A,
molecules should partially intercalate in the SmA phase and
the molecules are tilted 24 8 in the SmC phase when they
form a monolayer arrangement. On the other hand, 14ac10
(nZ10) had SmA, SmC, and smectic F (SmF) phases. The
SmF phase was assigned by the observation of the mosaic
texture. The X-ray diffraction study of 14ac10 (nZ10)
indicated that the layer spacings of the SmA, SmC, and SmF
1
characteristic peaks are reported. H NMR spectra were
recorded at 200 or 300 MHz with Varian Gemini-200 or
Mercury-300 spectrometers, using tetramethylsilane as
the internal standard. Mass spectra were taken on JEOL
AX-500. Elemental analyses were performed using
PerkinElmer 2400. The transition temperatures and the
mesomorphic phase were observed by a polarizing
microscope (Olympus BHSP BH-2) equipped with a hot
stage (Linkam TH-600RMS). Enthalpy changes were
measured using a differential scanning calorimeter (Seiko
DSC 200). The X-ray diffraction measurements were
carried out with a Rigaku Rint 2100 system using Ni-
filtered Cu Ka radiation at various temperatures. The
measuring temperatures were controlled with a Linkam
HFS-91 hot stage.
˚
˚
˚
phases were 33.1 A at 145 8C, 32.2 A at 130 8C, and 34.5 A
at 98 8C, respectively. The calculated molecular length of
˚
14ac10 (nZ10) is 37.5 A. The molecular packing models
are similar to those of 14aa10 (nZ10). The layer spacing of
the tilted SmF phase is slightly larger than that of the SmA
phase. It might be due to that the SmA phase has more
molten side chains than the SmF phase appeared at the
lower temperature. Monoethyl diethylene glycol esters
14ab4–14ab10 had a less stable SmA phase monotropi-
cally. The reduction of the thermal stability of 14ab4–
14ab10 might be due to the flexibility of the diethylene
glycol chain. The secondary amides 14ad4–14ad10 were
not mesomorphic because of the increase in molecular width
of their branching.
4.2. Preparation of aniline linkers 11, 15, and 17
4.2.1. Ethyl 6-(4-tert-butoxycarbonylaminophenoxy)hex-
anoate. To a mixture of ethyl 6-[(4-methylbenzenesulfonyl)-
oxy]hexanoate12 (1.09 g, 3.47 mmol) and potassium car-
bonate (1.67 g, 12.1 mmol) in acetonitrile (5 mL) was added
N-Boc-4-hydroxyaniline (0.722 g, 3.45 mmol) in aceto-
nitrile (5 mL). The reaction mixture was heated at reflux
for 17 h. After being cooled to room temperature, the
reaction was quenched by addition of saturated aqueous
NH4Cl (10 mL). The mixture was extracted with ethyl
acetate (3!15 mL). The combined organic layers were
dried over sodium sulfate and concentrated to furnish the
crude product, which was purified by flash chromatography
(silica gel 45 g, ethyl acetate/hexane 1:5) followed by
recrystallization (ethyl acetate/hexane) to give the product
(776 mg, 2.21 mmol, 64%) as a colorless needles: mp
Thioesters 14ac4–14ac10 exhibited liquid crystalline
properties with the higher thermal stability compared to
corresponding esters 14aa4–14aa10, and 14ab4–14ab10.
The thermal stability of the SmA phase of 14ac4–14ac10
was enhanced by approximately 60 8C when compared with
14aa4–14aa10 because the thioester linkage is superior in
linearity and longitudinal length to corresponding ester
linkage.10 The clearing temperature for 14b series (XZOH)
was 40–60 8C higher than that for 14a series (XZH) as a
result of hydrogen bond formation between azomethine
nitrogen and phenolic hydrogen, which enhanced the
planarity of the molecule.11 The thioesters possessing a
hydroxy group on the aromatic nuclei (14bc series, RZ
SC9H19, XZOH) showed smectic phase in the widest
temperature range.
1
73.2 8C; H NMR (300 MHz, CDCl3) d 1.26 (3H, t, JZ

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H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
7.1 Hz), 1.44–1.57 (2H, m), 1.51 (9H, s), 1.69 (2H, quint,
JZ7.4 Hz), 1.78 (2H, quint, JZ6.3 Hz), 2.33 (2H, t, JZ
7.4 Hz), 3.92 (2H, t, JZ6.3 Hz), 4.13 (2H, q, JZ7.1 Hz),
6.34 (1H, br s), 6.82 (2H, d, JZ8.8 Hz), 7.24 (2H, d, JZ
8.8 Hz); IR (ATR) 3364, 1733, 1690 cmK1; MS (CI): m/z
296 (100%), 351 ([M]C, 59%); HRMS (CI): calcd for
C19H29NO5 ([M]C), 351.2046, found 351.2057. Anal.
Calcd for C19H29NO5: C, 64.93; H, 8.32; N, 3.37. Found:
C, 65.21; H, 8.55; N, 4.14.
reacted with 4-(4-tert-butoxycarbonylaminophenyl)butyric
acid (8.32 g, 61.6 mmol, 4 equiv), HOBt$H2O (8.32 g,
61.6 mmol, 4 equiv), and DIC (19.3 mL, 123 mmol,
8 equiv) in a 4:1 solution (220 mL) of DCM and DMF at
room temperature for 15 h. The solution was removed by
decantation and the Lanterns were washed with DMF (3!
3 min) and DCM (3!3 min). The N-protected Lanterns
were shaken in DCM (500 mL, 2!3 h) containing 15%
TFA. The Lanterns were washed with DMF (3!3 min) and
treated with a 1:1 solution (500 mL) of DMF and DCM
containing 5% TEA (2!10 min). The solution was
removed by decantation and the Lanterns were washed
with a 1:1 solution of DMF and DCM (2!10 min) and
DCM (2!10 min) to give aniline linker 17.
4.2.2. 6-(4-tert-Butoxycarbonylaminophenoxy)hexanoic
acid. To a solution of ethyl 6-(4-tert-butoxycarbonyl-
aminophenoxy)hexanoate (776 mg, 2.21 mmol) in ethanol
(12 mL) was added 1 M NaOH solution (4 mL). The
reaction mixture was stirred at room temperature for 10 h
and quenched by addition of saturated aqueous NaH2PO4
(10 mL). The mixture was extracted with ethyl acetate (3!
15 mL). The combined organic layers were dried over
sodium sulfate and concentrated to give the crude product,
which was purified by flash chromatography (silica gel 30 g,
ethyl acetate) and followed by recrystallization (ethyl
acetate/hexane). The product (575 mg, 1.78 mmol, 81%)
Linkers 11, and 15 were prepared by the same procedure
above from 8 and 4-tert-butoxycarbonylaminobenzoic acid
or 6-(4-tert-butoxycarbonylaminophenoxy)hexanoic acid.
4.2.5. Loading of methyl 4-formylbenzoate and cleavage
with 4-octyloxyaniline using the resin 8, 11, 15 and 17.
Two pieces of the Lantern of the solid supported aniline 17
(A-series, loading 75 mmol!2, 150 mmol) were reacted
with methyl 4-formylbenzoate (130.5 mg, 790 mmol,
5.3 equiv) in DMF solution at room temperature for 24 h.
The solution was removed by decantation and the Lanterns
were washed with DMF (3!0.5 min) and DCM (3!
0.5 min) to give the solid supported ester 18. The solid
supported ester 18 was reacted with 4-octyloxyaniline
(132.8 mg, 4 equiv) in DMF (5 mL) at 50 8C for 3 h. The
Lanterns were washed with DMF (3!3 min). The
combined DMF solution was evaporated and purified by
HPLC (hexane/EtOAc 9:1) to give 10 in 94% yield
(51.9 mg, 141 mmol) as colorless solid. When the same
procedure was applied to the recovered resin, the product 10
was obtained in 89% yield.
1
was isolated as a colorless needles: mp 115 8C; H NMR
(300 MHz, CDCl3) d 1.45–1.57 (2H, m), 1.51 (9H, s), 1.71
(2H, quint, JZ7.6 Hz), 1.79 (2H, quint, JZ6.3 Hz), 2.39
(2H, t, JZ7.6 Hz), 3.92 (2H, t, JZ6.3 Hz), 6.45 (1H, br s),
6.81 (2H, d, JZ8.9 Hz), 7.23 (2H, d, JZ8.9 Hz); IR (ATR)
3362, 1697, 1672 cmK1; MS (CI): m/z 268 (100%), 323
([M]C, 62%); HRMS (CI): calcd for C17H25NO5 ([M]C),
323.1733, found 323.1727. Anal. Calcd for C17H25NO5: C,
63.14; H, 7.79; N, 4.33. Found: C, 63.35; H, 8.01; N, 4.51.
4.2.3. 6-(4-tert-Butoxycarbonylaminophenyl)butyric
acid. To a mixture of 4-(4-aminophenyl)butyric acid
(3.00 g, 16.7 mmol) in dioxane (25 mL) and water
(25 mL) were added triethylamine (3.6 mL, 25.8 mmol)
followed by di-tert-butyl dicarbonate (5.61 g, 25.7 mmol) in
dioxane (25 mL). The reaction mixture was stirred at room
temperature for 24 h and quenched slowly by addition of
3 M HCl solution (100 mL) to the reaction mixture. The
mixture was extracted with ethyl acetate (3!100 mL). The
combined organic layers were washed with brine (2!
60 mL), dried over sodium sulfate and concentrated to
furnish the crude product, which was further purified by
flash chromatography (silica gel 40 g, ethyl acetate/hexane
1:1). The product (4.36 g, 15.6 mmol, 94%) was isolated
as a colorless solid: mp 119.4 8C; 1H NMR (300 MHz,
DMSO-d6) d 1.47 (9H, s), 1.74 (2H, tt, JZ 8.2, 7.4 Hz), 2.16
(2H, t, JZ7.4 Hz), 2.50 (2H, t, JZ8.2 Hz), 7.05 (2H, d, JZ
8.5 Hz), 7.36 (2H, d, JZ8.5 Hz), 9.23 (1H, s); IR (ATR)
1700, 1522 cmK1; MS (CI): m/z 223 (100%), 279 ([M]C,
39%); HRMS (CI): calcd for C15H21NO4 ([M]C), 279.1471,
found 279.1461. Anal. Calcd for C15H21NO4: C, 64.50; H,
7.58; N, 5.01. Found: C, 64.64; H, 7.77; N, 5.18.
The same procedures were also tested to the resin 8, 11, and
15. Their yields were described in the text.
Mp 135.5–136 8C; 1H NMR (200 MHz, CDCl3) d 0.89 (3H,
t, JZ7.0 Hz), 1.21–1.54 (12H, m), 1.80 (2 H, m), 3.95 (3H,
s), 3.98 (2H, d, JZ6.6 Hz), 6.94 (2H, d, JZ8.8 Hz), 7.27
(2H, d, JZ8.8 Hz), 7.96 (2H, d, JZ8.4 Hz), 8.13 (2H, d,
JZ8.4 Hz), 8.54 (1H, s); IR (ATR) 1721, 1621 cmK1; MS
(CI): m/z 368 ([MCH]C, 100%); HRMS (CI): calcd for
C23H30NO3 ([MCH]C), 368.2226, found 368.2235. Anal.
Calcd for C23H29NO3: C, 75.17; H, 7.95; N, 3.81. Found: C,
75.14; H, 7.95; N, 3.78.
4.2.6. Loading of 4-formylbenzic acid, condensation with
1-nonanol and cleavage with 4-octyloxyaniline on the
resin 15 and 17. Three pieces of the solid supported aniline
17 (A-series, loading 75 mmol!3, 225 mmol) were reacted
with 4-carboxybenzaldehyde (179.4 mg, 1.19 mmol,
5.3 equiv) in DMF solution (4 mL) at room temperature
for 24 h. The solution was removed by decantation and the
Lanterns were washed with DMF (3!0.5 min), and DCM
(3!0.5 min) to give the solid supported azomethine 19a.
The azomethine 19a were reacted with 4-N,N-dimethyl-
aminopyridine (6.9 mg, 56 mmol, 0.25 equiv), 1-nonanol
(157 mL, 900 mmol, 4 equiv) and 1,3-diisopropylcarbo-
diimide (273 mL, 1.76 mmol, 8 equiv) in DCM (4 mL) at
4.2.4. Acylation and Boc-deprotection on the Synphase
Lantern. Four hundred and five pieces of the aminomethyl-
ated Lantern 8 (D-series, loading: 38 mmol!405,
15.4 mmol) were shaken twice for 10 min in a 1:1 solution
(500 mL) of DMF and DCM containing 5% TEA. The
solution was removed by decantation and the Lanterns were
shaken with a 1:1 solution of DMF and DCM (3!3 min)
and DCM (2!10 min). The neutralized Lanterns were

H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
10649
room temperature for 3 h. The solution was removed
by decantation and the Lanterns were washed with DMF
(3!0.5 min), and DCM (3!0.5 min) to give the solid
supported nonyl ester 22aa. The solid supported ester 22aa
were reacted with 4-n-octyloxyaniline (202 mg, 0.91 mmol,
4 equiv) in DMF (5 mL) at 50 8C for 3 h. The Lanterns were
washed with DMF (3!3 min). The combined DMF
solution was evaporated and purified by HPLC (hexane/
EtOAc 19:1) to give 14aa8 (nZ8) in 66% yield (71.2 mg,
148 mmol) as pale yellow solid. When the same procedure
was applied to the recovered resin, the product 14aa8 was
obtained in 40% yield (43.5 mg, 90.7 mmol). The resulting
lantern was treated with methyl 4-formylbenzoate
(147.7 mg, 900 mmol, 4 equiv) in DMF at 50 8C for 3 h.
The Lanterns were washed with DMF (3!3 min). The
combined DMF solution was evaporated and purified by
HPLC (hexane/EtOAc 4:1) to give 10 in 15% yield
(12.4 mg, 33.7 mmol) as pale yellow solid.
All new compounds described gave satisfied spectral and
elemental analytic data. One example of spectral data for
one homologue of each compound type and only elemental
analytic data of new compounds are given.
4.3.3.1. Nonyl 4-[(4-butoxyphenylimino)methyl]ben-
zoate (14aa4, nZ4). Pale yellow needles; 1H NMR
(200 MHz, CDCl3) d 0.88 (3H, t, JZ6.8 Hz), 0.99 (3H, t,
JZ7.1 Hz), 1.28–1.60 (14H, m), 1.72–1.82 (4H, m), 3.99
(2H, t, JZ6.6 Hz), 4.34 (2H, t, JZ6.6 Hz), 6.93 (2H, d, JZ
8.8 Hz), 7.27 (2H, d, JZ8.8 Hz), 7.95 (2H, d, JZ8.3 Hz),
8.12 (2H, d, JZ8.3 Hz), 8.54 (1H, s); IR (ATR) 1710,
1620 cmK1; MS (CI): m/z 423 ([M]C, 100%); HRMS (CI):
calcd for C27H37NO3 ([M]C), 423.2773, found 423.2774.
Anal. Calcd for C27H37NO3: C, 76.56; H, 8.80; N, 3.31.
Found: C, 76.85; H, 9.09; N, 3.37.
4.3.3.2. Nonyl 4-[(4-pentyloxyphenylimino)methyl]-
benzoate (14aa5, nZ5). Pale yellow needles. Anal. Calcd
for C28H39NO3: C, 76.85; H, 8.98; N, 3.20. Found: C, 77.03;
H, 9.15; N, 3.28.
The same procedures were also tested to the resin 11. The
product 14aa8 (nZ8) was obtained in 47% yield (50.8 mg,
106 mmol) as pale yellow solid.
4.3.3.3. Nonyl 4-[(4-hexyloxyphenylimino)methyl]-
benzoate (14aa6, nZ6). Pale yellow needles. Anal. Calcd
for C29H41NO3: C, 77.12; H, 9.15; N, 3.10. Found: C, 77.30;
H, 9.41; N, 3.23.
4.3. Parallel synthesis of liquid crystalline library on the
solid support 17
4.3.1. Loading of 4-formylbenzic acid (synthesis of 19a).
Eighty four pieces of the solid supported aniline 17
(D-series, loading: 38 mmol!84, 3.19 mmol) were reacted
with 4-carboxybenzaldehyde (2.54 g, 16.9 mmol, 5.3 equiv)
in DMF solution (80 mL) at room temperature for 24 h. The
solution was removed by decantation and the Lanterns were
washed with DMF (3!0.5 min), and DCM (3!0.5 min).
4.3.3.4. Nonyl 4-[(4-heptyloxyphenylimino)methyl]-
benzoate (14aa7, nZ7). Pale yellow needles. Anal. Calcd
for C30H43NO3: C, 77.38; H, 9.31; N, 3.01. Found: C, 77.64;
H, 9.50; N, 3.12.
4.3.3.5. Nonyl 4-[(4-octyloxyphenylimino)methyl]ben-
zoate (14aa8, nZ8). Pale yellow needles. Anal. Calcd for
C31H45NO3: C, 77.62; H, 9.46; N, 2.92. Found: C, 77.76; H,
9.74; N, 3.03.
Compound 19b was also synthesized by the same procedure
as described above.
4.3.3.6. Nonyl 4-[(4-nonyloxyphenylimino)methyl]-
benzoate (14aa9, nZ9). Pale yellow needles. Anal. Calcd
for C32H47NO3: C, 77.85; H, 9.60; N, 2.84. Found: C, 78.04;
H, 9.79; N, 2.99.
4.3.2. Condensation with 1-nonanol (synthesis of 22aa).
Twenty eight pieces of the solid supported azomethine 19aa
(D-series, loading: 38 mmol!28, 1.06 mmol) were reacted
with 4-N,N-dimethylaminopyridine (32.5 mg, 0.266 mmol,
0.25 equiv), 1-nonanol (0.74 mL, 4.2 mmol, 4 equiv) and
1,3-diisopropylcarbodiimide (1.3 mL, 8.5 mmol, 8 equiv) in
DCM at room temperature for 3 h. The solution was
removed by decantation and the Lanterns were washed with
DMF (3!0.5 min), and DCM (3!0.5 min).
4.3.3.7. Nonyl 4-[(4-decyloxyphenylimino)methyl]-
benzoate (14aa10, nZ10). Pale yellow needles. Anal.
Calcd for C33H49NO3: C, 78.06; H, 9.73; N, 2.76. Found: C,
78.02; H, 9.50; N, 2.90.
4.3.3.8. 2-(2-Ethoxyethoxy)ethyl 4-[(4-butoxyphenyl-
imino)methyl]benzoate (14ab4, nZ4). Pale yellow
needles; H NMR (300 MHz, CDCl3) d 0.99 (3H, t, JZ
Compounds 22ab, 22ac, 22ad, 22ba and 22bc were also
synthesized by the same procedure as described above.
1
7.3 Hz), 1.21 (3H, t, JZ7.0 Hz), 1.51 (2H, qt, JZ7.0,
6.6 Hz), 1.78 (2H, quint, JZ6.6 Hz), 3.54 (2H, q, JZ
7.3 Hz), 3.63 (2H, m), 3.71 (2H, m), 3.87 (2H, t, JZ4.8 Hz),
3.99 (2H, t, JZ6.6 Hz), 4.52 (2H, t, JZ4.8 Hz), 6.94 (2H, d,
JZ8.8 Hz), 7.27 (2H, d, JZ8.8 Hz), 7.95 (2H, d, JZ
8.4 Hz), 8.15 (2H, d, JZ8.4 Hz), 8.54 (1H, s); IR (ATR)
1705, 1621 cmK1; MS (CI): m/z 413 ([M]C, 100%); HRMS
(CI): calcd for C24H31NO5 ([M]C), 413.2202, found
413.2188. Anal. Calcd for C24H31NO5: C, 69.71; H,7.56;
N, 3.39. Found: C, 69.86; H, 7.39; N, 3.44.
4.3.3. Cleavage from the solid support (synthesis of
14aa4). Two pieces of the solid supported ester 22aa (D-
series, loading: 38 mmol!2, 76 mmol) were reacted with 4-
n-butyloxyaniline (63 mg, 0.38 mmol, 5 equiv) in DMF
(5 mL) at 50 8C for 3 h. The Lanterns were washed with
DMF (3!3 min). The combined DMF solution was
evaporated and purified by HPLC (hexane/EtOAc 19:1) to
give 14aa4 (nZ4) in 55% yield (17.8 mg, 42.0 mmol) as
pale yellow solid.
All library members were also synthesized by the same
procedure as described above.
4.3.3.9. 2-(2-Ethoxyethoxy)ethyl 4-[(4-pentyloxyphenyl-
imino)methyl]benzoate (14ab5, nZ5). Pale yellow needles.

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H. Hioki et al. / Tetrahedron 61 (2005) 10643–10651
Anal. Calcd for C25H33NO5: C, 70.23; H,7.78; N, 3.28.
Found: C, 70.27; H, 7.90; N, 3.28.
Calcd for C32H47NO2S: C, 75.39; H, 9.29; N, 2.75. Found:
C, 75.30; H, 9.53; N, 3.03.
4.3.3.21. S-Nonyl 4-[(4-decyloxyphenylimino)methyl]-
thiobenzoate (14ac10, nZ10). Pale yellow needles. Anal.
Calcd for C33H49NO2S: C, 75.67; H, 9.43; N, 2.67. Found:
C, 75.97; H, 9.75; N, 2.84.
4.3.3.10. 2-(2-Ethoxyethoxy)ethyl 4-[(4-hexyloxyphenyl-
imino)methyl]benzoate (14ab6, nZ6). Pale yellow needles.
Anal. Calcd for C26H35NO5: C, 70.72; H, 7.99; N, 3.17.
Found: C, 70.87; H, 8.10; N, 3.16.
4.3.3.22. N,N-Diisobutyl-4-[(4-butoxyphenylimino)-
methyl]benzamide (14ad4, nZ4). Pale yellow needles;
1H NMR (200 MHz, CDCl3) d 0.74 (6H, d, JZ6.6 Hz), 0.99
(3H, t, JZ7.3 Hz), 1.01 (6H, d, JZ7.0 Hz), 1.53 (2H, m),
1.80 (3H, m), 2.14 (1H, m), 3.10 (2H, d, JZ7.3 Hz), 3.38
(2H, d, JZ7.7 Hz), 3.99 (2H, t, JZ6.6 Hz), 6.94 (2H, d, JZ
8.8 Hz), 7.24 (2H, d, JZ8.8 Hz), 7.45 (2H, d, JZ8.1 Hz),
4.3.3.11. 2-(2-Ethoxyethoxy)ethyl 4-[(4-heptyloxy-
phenylimino)methyl]benzoate (14ab7, nZ7). pale yellow
needles. Anal. Calcd for C27H37NO5: C, 71.18; H, 8.19; N,
3.07. Found: C, 71.43; H, 8.38; N, 2.95.
4.3.3.12. 2-(2-Ethoxyethoxy)ethyl 4-[(4-octyloxy-
phenylimino)methyl]benzoate (14ab8, nZ8). Pale yellow
needles. Anal. Calcd for C28H39NO5: C, 71.61; H, 8.37; N,
2.98. Found: C, 71.86; H, 8.56; N, 2.97.
7.91 (2H, d, JZ8.1 Hz), 8.52 (1H, s); IR (ATR) 1622 cmK1
;
MS (CI): m/z 409 ([MC1]C, 100%); HRMS (CI): calcd for
C26H37N2O2 ([MCH]C), 409.2855, found 409.2872. Anal.
Calcd for C26H36N2O2: C, 76.43; H, 8.88; N, 6.86. Found:
C, 76.62; H, 9.07; N, 6.89.
4.3.3.13. 2-(2-Ethoxyethoxy)ethyl 4-[(4-nonyloxy-
phenylimino)methyl]benzoate (14ab9, nZ9). Pale yellow
needles. Anal. Calcd for C29H41NO5: C, 72.02; H, 8.54; N,
2.90. Found: C, 72.29; H, 8.82; N, 3.07.
4.3.3.23. N,N-Diisobutyl-4-[(4-pentyloxyphenylimino)-
methyl]benzamide (14ad5, nZ5). Pale yellow needles.
Anal. Calcd for C27H38N2O2: C, 76.74; H, 9.06; N, 6.63.
Found: C, 76.65; H, 9.37; N, 6.60.
4.3.3.14. 2-(2-Ethoxyethoxy)ethyl 4-[(4-decyloxy-
phenylimino)methyl]benzoate (14ab10, nZ10). Pale
yellow needles. Anal. Calcd for C30H43NO5: C, 72.40; H,
8.71; N, 2.81. Found: C, 72.42; H, 8.78; N, 2.85.
4.3.3.24. N,N-Diisobutyl-4-[(4-hexyloxyphenylimino)-
methyl]benzamide (14ad6, nZ6). Pale yellow needles.
Anal. Calcd for C28H40N2O2: C, 77.02; H, 9.23; N, 6.42.
Found: C, 77.19; H, 9.55; N, 6.43.
4.3.3.15. S-Nonyl 4-[(4-butoxyphenylimino)methyl]-
thiobenzoate (14ac4, nZ4). Pale yellow needles; 1H
NMR (200 MHz, CDCl3) d 0.88 (3H, t, JZ6.6 Hz), 0.98
(3H, t, JZ7.3 Hz), 1.20–1.88 (18H, m), 3.09 (2H, t, JZ
7.3 Hz), 3.99 (2H, t, JZ6.2 Hz), 6.94 (2H, d, JZ9.2 Hz),
7.27 (2H, d, JZ9.2 Hz), 7.95 (2H, d, JZ8.1 Hz), 8.05 (2H,
4.3.3.25. N,N-Diisobutyl-4-[(4-heptyloxyphenylimino)-
methyl]benzamide (14ad7, nZ7). Pale yellow needles.
Anal. Calcd for C29H42N2O2: C, 77.29; H, 9.39; N, 6.22.
Found: C, 77.26; H, 9.69; N, 6.22.
d, JZ8.1 Hz), 8.53 (1H, s); IR (ATR) 1650, 1620 cmK1
;
MS (CI): m/z 439 ([M]C, 100%); HRMS (CI): calcd for
C27H37NO2S ([M]C), 439.2545, found 439.2569. Anal.
Calcd for C27H37NO2S: C, 73.76; H, 8.48; N, 3.19. Found:
C, 73.65; H, 8.51; N, 3.24.
4.3.3.26. N,N-Diisobutyl-4-[(4-octyloxyphenylimino)-
methyl]benzamide (14ad8, nZ8). Pale yellow needles.
Anal. Calcd for C30H44N2O2: C, 77.54; H, 9.54; N, 6.03.
Found: C, 77.76; H, 9.55; N, 6.06.
4.3.3.16. S-Nonyl 4-[(4-pentyloxyphenylimino)methyl]-
thiobenzoate (14ac5, nZ5). Pale yellow needles. Anal.
Calcd for C28H39NO2S: C, 74.13; H, 8.66; N, 3.09. Found:
C, 74.17; H, 8.37; N, 3.25.
4.3.3.27. N,N-Diisobutyl-4-[(4-nonyloxyphenylimino)-
methyl]benzamide (14ad9, nZ9). Pale yellow needles.
Anal. Calcd for C31H46N2O2: C, 77.78; H, 9.69; N, 5.85.
Found: C, 77.79; H, 9.97; N, 5.84.
4.3.3.17. S-Nonyl 4-[(4-hexyloxyphenylimino)methyl]-
thiobenzoate (14ac6, nZ6). Pale yellow needles. Anal.
Calcd for C29H41NO2S: C, 74.47; H, 8.84; N, 2.99. Found:
C, 74.68; H, 9.12; N, 3.08.
4.3.3.28. N,N-Diisobutyl-4-[(4-decyloxyphenylimino)-
methyl]benzamide (14ad10, nZ10). Pale yellow needles.
Anal. Calcd for C32H48N2O2: C, 78.00; H, 9.82; N, 5.69.
Found: C, 78.12; H, 10.04; N, 5.66.
4.3.3.18. S-Nonyl 4-[(4-heptyloxyphenylimino)methyl]-
thiobenzoate (14ac7, nZ7). Pale yellow needles. Anal.
Calcd for C30H43NO2S: C, 74.80; H, 9.00; N, 2.91. Found:
C, 74.83; H, 9.21; N, 3.00.
4.3.3.29. Nonyl 4-[(4-butoxyphenylimino)methyl]-3-
hydroxybenzoate (14ba4, nZ4). Yellow needles; 1H
NMR (200 MHz, CDCl3) d 0.89 (3H, t, JZ6.8 Hz), 0.99
(3H, t, JZ6.6 Hz), 1.25–1.60 (14H, m), 1.70–1.86 (4H, m),
4.00 (2H, t, JZ6.6 Hz), 4.32 (2H, t, JZ6.6 Hz), 6.95 (2H,
d, JZ9.0 Hz), 7.30 (2H, d, JZ9.0 Hz), 7.43 (1H, d, JZ
8.1 Hz), 7.60 (1H, dd, JZ8.1, 1.1 Hz), 7.67 (1H, d, JZ
1.5 Hz), 8.66 (1H, s); 13.48 (1H, s); 13.50 (1H, s); IR (ATR)
1713, 1616 cmK1; MS (CI): m/z 440 ([MCH]C, 100%);
HRMS (CI): calcd for C27H38NO4 ([MCH]C), 440.2801,
found 440.2799. Anal. Calcd for C27H37NO4: C, 73.77; H,
8.48; N, 3.19. Found: C, 73.79; H, 8.65; N, 3.17.
4.3.3.19. S-Nonyl 4-[(4-octyloxyphenylimino)methyl]-
thiobenzoate (14ac8, nZ8). Pale yellow needles. Anal.
Calcd for C31H45NO2S: C, 75.10; H, 9.15; N, 2.83. Found:
C, 74.87; H, 9.39; N, 2.97
4.3.3.20. S-Nonyl 4-[(4-nonyloxyphenylimino)methyl]-
thiobenzoate (14ac9, nZ9). Pale yellow needles. Anal.

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10651
4.3.3.30. Nonyl 4-[(4-pentyloxyphenylimino)methyl]-
3-hydroxybenzoate (14ba5, nZ5). Yellow needles. Anal.
Calcd for C28H39NO4: C, 74.14; H, 8.67; N, 3.09. Found: C,
73.93; H, 8.85; N, 3.09.
4.3.3.40. S-Nonyl 4-[(4-octyloxyphenylimino)methyl]-
3-hydroxybenzoate (14bc8, nZ8). Light orange needles.
Anal. Calcd for C31H45NO3S: C, 72.76; H, 8.86; N, 2.74.
Found: C, 73.02; H, 9.13; N, 2.81.
4.3.3.31. Nonyl 4-[(4-hexyloxyphenylimino)methyl]-3-
hydroxybenzoate (14ba6, nZ6). Yellow needles. Anal.
Calcd for C29H41NO4: C, 74.48; H, 8.84; N, 3.00. Found: C,
74.58; H, 8.51; N, 3.11.
4.3.3.41. S-Nonyl 4-[(4-nonyloxyphenylimino)-
methyl]-3-hydroxybenzoate (14bc9, nZ9). Light orange
needles. Anal. Calcd for C32H47NO3S: C, 73.10; H, 9.01; N,
2.66. Found: C, 73.08; H, 9.27; N, 2.73.
4.3.3.32. Nonyl 4-[(4-heptyloxyphenylimino)methyl]-
3-hydroxybenzoate (14ba7, nZ7). Yellow needles. Anal.
Calcd for C30H43NO4: C, 74.81; H, 9.00; N, 2.91. Found: C,
74.60; H, 9.20; N, 2.97.
4.3.3.42. S-Nonyl 4-[(4-decyloxyphenylimino)methyl]-
3-hydroxybenzoate (14bc10, nZ10). Light orange
needles. Anal. Calcd for C33H49NO3S: C, 73.42; H, 9.15;
N, 2.59. Found: C, 73.70; H, 9.44; N, 2.68.
4.3.3.33. Nonyl 4-[(4-octyloxyphenylimino)methyl]-3-
hydroxybenzoate (14ba8, nZ8). Yellow needles. Anal.
Calcd for C31H45NO4: C, 74.96; H, 9.33; N, 2.82. Found: C,
75.14; H, 9.27; N, 2.88.
Supplementary data
4.3.3.34. Nonyl 4-[(4-nonyloxyoxyphenylimino)-
methyl]-3-hydroxybenzoate (14ba9, nZ9). Yellow
needles. Anal. Calcd for C32H47NO4: C, 75.40; H, 9.29;
N, 2.75. Found: C, 75.43; H, 9.52; N, 2.79.
Supplementary data associated with this article can be found,
in the online version, at doi:10.1016/j.tet.2005.08.086
4.3.3.35. Nonyl 4-[(4-decyloxyphenylimino)methyl]-3-
hydroxybenzoate (14ba10, nZ10). Yellow needles. Anal.
Calcd for C33H49NO4: C, 75.68; H, 9.43; N, 2.67. Found: C,
75.48; H, 9.03; N, 2.59.
References and notes
4.3.3.36. S-Nonyl 4-[(4-butoxyphenylimino)methyl]-3-
hydroxybenzoate (14bc4, nZ4). Light orange needles; 1H
NMR (300 MHz, CDCl3) d 0.88 (3H, t, JZ6.9 Hz), 0.99
(3H, t, JZ7.1 Hz), 1.21–1.36 (10H, m), 1.38–1.58 (4H, m),
1.68 (2H, m), 1.79 (2H, m), 3.07 (2H, t, JZ7.1 Hz), 4.00
(2H, t, JZ6.3 Hz), 6.95 (2H, d, JZ9.1 Hz), 7.30 (2H, d, JZ
9.1 Hz), 7.43 (1H, d, JZ8.0 Hz), 7.50 (1H, dd, JZ8.0,
1.6 Hz), 7.59 (1H, d, JZ1.6 Hz), 8.65 (1H, s), 13.55 (1H, s);
IR (ATR) 1651, 1626 cmK1; MS (CI): m/z 456 ([MCH]C,
100%); HRMS (CI): calcd for C27H38NO3S ([MCH]C),
456.2572, found 456.2589. Anal. Calcd for C27H37NO3S: C,
71.17; H, 8.18; N, 3.07. Found: C, 71.21; H, 8.29; N, 3.45.
1. Guillier, F.; Orain, D.; Bradley, M. Chem. Rev. 2000, 100,
2091–2157.
2. Blaney, P.; Grigg, R.; Sridharan, V. Chem. Rev. 2002, 102,
2607–2624. Takahashi, T.; Inoue, H.; Yamamura, Y.; Doi, T.
Angew. Chem., Int. Ed. 2001, 40, 3230–3233.
3. Mori, A.; Akahoshi, I.; Hashimoto, M.; Doi, T.; Takahashi, T.
Tetrahedron Lett. 2004, 45, 813–815.
4. Hashimoto, M.; Mori, A.; Inoue, H.; Nagamiya, H.; Doi, T.;
Takahashi, T. Tetrahedron Lett. 2003, 44, 1251–1254.
5. Haino, T.; Tanaka, M.; Ideta, K.; Kubo, K.; Mori, A.;
Fukazawa, Y. Tetrahedron Lett. 2004, 45, 2277–2279.
6. Kang, S.; Thisayukta, J.; Takezoe, H.; Watanabe, J.; Ogino,
K.; Doi, T.; Takahashi, T. Liq. Cryst. 2004, 31, 1323–1336.
7. The preliminary account has been published. Hioki, H.;
Fukutaka, M.; Takahashi, H.; Kodama, M.; Kubo, K.; Ideta,
K.; Mori, A. Tetrahedron Lett. 2004, 45, 7591–7594.
8. Demus, D.; Goodby, J.; Gray, G. W.; Spiess, H.-W.; Vill, V.
Handbook of Liquid Crystals; VCH: Weinheim, 1998.
9. Condensation of resin-bound aniline and aromatic aldehydes
was reported, see: Patteux, C.; Levacher, V.; Dupas, G. Org.
Lett. 2003, 5, 3061–3063.
4.3.3.37. S-Nonyl 4-[(4-pentyloxyphenylimino)-
methyl]-3-hydroxybenzoate (14bc5, nZ5). Light orange
needles. Anal. Calcd for C28H39NO3S: C, 71.60; H, 8.37; N,
2.98. Found: C, 71.80; H, 8.52; N, 3.07.
4.3.3.38. Nonyl 4-[(4-hexyloxyphenylimino)methyl]-3-
hydroxybenzoate (14bc6, nZ6). Light orange needles.
Anal. Calcd for C29H41NO3S: C, 72.01; H, 8.54; N, 2.90.
Found: C, 72.27; H, 8.80; N, 2.96.
10. Kelker, H.; Hatz, R. Handbook of Liquid Crystals; Chemie
GmbH: Weinheim, 1998; p 55.
4.3.3.39. S-Nonyl 4-[(4-heptyloxyphenylimino)-
methyl]-3-hydroxybenzoate (14bc7, nZ7). Light orange
needles. Anal. Calcd for C30H43NO3S: C, 72.39; H, 8.71; N,
2.81. Found: C, 72.38; H, 8.96; N, 2.92.
11. Sakagami, S.; Takase, A. Chem. Lett. 1995, 521–522.
12. Burns, D. H.; Miller, J. D.; Chan, H.-K.; Delaney, M. O. J. Am.
Chem. Soc. 1997, 119, 2125–2133.