Synthesis and characterization of some novel higher C,N-diphenyl nitrones, isoxazolines, and mercaptobenzimidazoles as oleochemicals

Article abstract of DOI:10.1080/10426507.2012.657312

Some novel long-chain nitrones, isoxazolines, and (1H-benzo[d]-imidazol-2- ylthio) derivatives were synthesized. Nitrones, N-{4-[2-(tetradecylthio)acetoxy] benzylidene}aniline oxide, and N-[4-(12-oxo-2,5,8,11-tetraoxadocosan-22-yloxy) benzylidene]aniline oxide were prepared via the reaction of -phenylhydroxylamine with the corresponding aromatic aldehydes. The isoxazolines were prepared from undec-10-en-1-ol and benzonitrile-N-oxide which was generated in situ. The 1H-benzo[d]-imidazol-2-ylthio derivatives were synthesized via the replacement reaction of -bromo esters and 2-mercaptobenzimidazole.

Full text of DOI:10.1080/10426507.2012.657312

This article was downloaded by: [Moskow State Univ Bibliote]
On: 04 October 2013, At: 13:34
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered
office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Phosphorus, Sulfur, and Silicon and the
Related Elements
Publication details, including instructions for authors and
subscription information:
http://www.tandfonline.com/loi/gpss20
Synthesis and Characterization
of Some Novel Higher C,N-
Diphenyl Nitrones, Isoxazolines,
and Mercaptobenzimidazoles as
Oleochemicals
A. Yıldırım a & M. Çetin a
a Department of Chemistry, Uludağ University, Bursa, Turkey
Accepted author version posted online: 23 Jan 2012.
To cite this article: A. Yıldırım & M. Çetin (2012) Synthesis and Characterization of
Some Novel Higher C,N-Diphenyl Nitrones, Isoxazolines, and Mercaptobenzimidazoles as
Oleochemicals, Phosphorus, Sulfur, and Silicon and the Related Elements, 187:8, 952-964, DOI:
10.1080/10426507.2012.657312
To link to this article: http://dx.doi.org/10.1080/10426507.2012.657312
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the
“Content”) contained in the publications on our platform. However, Taylor & Francis,
our agents, and our licensors make no representations or warranties whatsoever as to
the accuracy, completeness, or suitability for any purpose of the Content. Any opinions
and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
should not be relied upon and should be independently verified with primary sources
of information. Taylor and Francis shall not be liable for any losses, actions, claims,
proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or
howsoever caused arising directly or indirectly in connection with, in relation to or arising
out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any
substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,
systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &

Conditions of access and use can be found at http://www.tandfonline.com/page/terms-
and-conditions

Phosphorus, Sulfur, and Silicon, 187:952–964, 2012
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2012.657312
SYNTHESIS AND CHARACTERIZATION OF SOME NOVEL
HIGHER C,N-DIPHENYL NITRONES, ISOXAZOLINES,
AND MERCAPTOBENZIMIDAZOLES AS OLEOCHEMICALS
A. Yıldırım and M. C¸ etin
Department of Chemistry, Uludag˘ University, Bursa, Turkey
GRAPHICAL ABSTRACT
O
H
S
O
O
S
N
N
N
O
26
O
S
N
HN
Abstract Some novel long-chain nitrones, isoxazolines, and (1H-benzo[d]-imidazol-2-ylthio)
derivatives were synthesized. Nitrones, N-{4-[2-(tetradecylthio)acetoxy]benzylidene}aniline
oxide, and N-[4-(12-oxo-2,5,8,11-tetraoxadocosan-22-yloxy)benzylidene]aniline oxide were
prepared via the reaction of β-phenylhydroxylamine with the corresponding aromatic aldehy-
des. The isoxazolines were prepared from undec-10-en-1-ol and benzonitrile-N-oxide which
was generated in situ. The 1H-benzo[d]-imidazol-2-ylthio derivatives were synthesized via the
replacement reaction of ω-bromo esters and 2-mercaptobenzimidazole.
Keywords Benzimidazoles; fatty acids; isoxazolines; nitrones
INTRODUCTION
Synthetic fatty acids and their derivatives are widely used products, mainly as in-
dustrial raw materials. Examples for potential uses of these materials include oil field
chemicals.1 Long-chain compounds are widely used in the oil industry as corrosion in-
hibitors.2–5 Industrial corrosion is a serious problem that causes severe economic losses
Received 8 November 2011; accepted 9 January 2012.
Address correspondence to A. Yıldırım, Department of Chemistry, Uludag˘ University, Bursa, Turkey.
E-mail: yildirim@uludag.edu.tr
952

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
953
because of destruction-based process of metal and alloy equipments and devaluation of
industrial products.
Long-chain N-alkyl-α-alkyl nitrones are exceptionally effective as process stabilizers
for polyolefins.6 Some homologous nitrones display mesomorphic properties.7 There are
many methods known in the literature for the synthesis of nitrones. For instance, nitrones
can be obtained via the oxidation of secondary amines with oxone as the sole oxidant in a
biphasic basic medium,8 via the manganese dioxide oxidation of hydroxylamines,9 and via
the condensation reaction between aldehydes and hydroxylamine.10
There is a literature report describing the pharmacological properties of isoxazo-
lines.11 Isoxazolines are generally prepared by 1,3-dipolar cycloaddition between alkenes
and nitrile oxides which are generated in situ.3,12 Benzimidazole derivatives exhibit a wide
range of pharmacological activities and industrial applications.13–15
RESULTS AND DISCUSSION
The starting 2-(tetradecylthio)acetic acid (3) was prepared according to a procedure
given in a patent16 with some modifications. Thereafter, this acid was reacted with two
equivalents of oxalyl chloride to give the desired acyl chloride (4). 2-(Tetradecylthio)acetyl
chloride (4) was treated with 4-hydroxybenzaldehyde to give a good yield of aldehyde
(5) (Scheme 1). The IR spectrum of the compound showed peaks at 1760 cm–1 and 1720
cm–1 for the COO and CHO groups, respectively. The 1H NMR spectrum of the compound
showed singlets at δ 10.01 ppm and δ 3.45 ppm for the CHO and the CH2SCH2COO
groups, respectively. Thereafter, the aldehyde 5 was treated with β-phenylhydroxylamine17
Scheme 1

954
A. YILDIRIM AND M. C¸ ETIN
in a dark and closed vessel to afford the nitrone as a white crystalline compound with 61%
yield after crystallization from THF. The absence of a peak for CHO in the IR and 1H NMR
spectra confirmed the structure of the condensation product. The characteristic IR peaks of
6 were observed at 1753 cm–1 for the COO group, at 1554 cm–1 for the C=N group, and at
1167 cm–1 for the N–O group. The 1H NMR spectrum of 6 showed a singlet at δ 7.94 ppm
for the ON=CH group.
Here we report also syntheses of compounds 11 and 13 with one-tailed hydrophobic
groups (Schemes 2 and 3). To accomplish the synthesis of the 11, first 11-bromoundecanoic
acid (7) was converted to its acyl chloride (8) by treatment with oxalyl chloride which
provided the desired ester 9 after reaction with triethylene glycol monomethyl ether. The
isolated ester 9 exhibited acceptable purity for the IR analysis. Then, this compound was
heated with 4-hydroxybenzaldehyde in the presence of potassium carbonate and catalytic
amounts of sodium iodide in anhydrous acetone to afford the aromatic long-chain aldehyde
10 as a colorless oil with 72% yield. Characteristic IR peaks were obtained at 1732 cm–1
for the COO group and at 1688 cm–1 for the CHO group. The 1H NMR spectrum showed
two singlets at δ 9.87 ppm for the CHO group and at δ 3.38 ppm for the OCH3 group. The
amphiphilic nitrone N-[4-(12-oxo-2,5,8,11-tetraoxadocosan-22-yloxy)benzylidene]aniline
oxide (11) was obtained with 57% yield upon reaction of 10 with β-phenylhydroxylamine
in the dark (Scheme 2).
For the synthesis of the amphiphilic 2-[2-(2-methoxyethoxy)ethoxy]ethyl-11-(1H-
benzo[d]imidazol-2-ylthio)undecanoate (13), the ester 9 obtained in Scheme 2 was heated
with 2-mercaptobenzimidazole18 12 in the presence of potassium carbonate and a catalytic
amount of sodium iodide.
Scheme 2

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
955
Scheme 3
Undec-10-en-1-ol (15) was synthesized by reduction of undec-10-enoic acid (14)
with lithium alanate. Then, the unsaturated alcohol 15 and benzonitrile-N-oxide (16) were
reacted to give isoxazoline 17 via cycloaddition reaction (Scheme 4). Benzonitrile-N-oxide
(16) was generated in situ as described by Hassner and Lokanatha.19 The cycloadduct 17
was oxidized with pyridinium chlorochromate to give the corresponding aldehyde 18. The
IR spectrum of 18 showed an absorption band at 1716 cm–1 due to the CHO stretching
vibration. The adsorption band at 3279 cm–1 due to the OH group of 17 disappeared.
Scheme 4
The oxidized product also confirms the chemical structure of the prepared isox-
azoline 17. For the synthesis of 21, first isoxazoline 17 was treated with chloroacetyl
chloride (19) to give the chloroacetylated isoxazoline 20 in quantitative yield as a white
waxy solid, which was used as obtained in the next step. Finally, 20 was heated with
2-mercaptobenzimidazole (12), in the presence of potassium carbonate and a catalytic
amount of sodium iodide. Purification of the crude product on a short column packed
with silica gel and petroleum ether-dichloromethane as eluent yielded 76% of pure 21 as a
yellowish–orange solid (Scheme 5). In the 1H NMR spectrum of the 21, the protons of the
methylene SCH2COO group showed a singlet at δ 3.95 ppm.

956
A. YILDIRIM AND M. C¸ ETIN
Scheme 5
2-(Dodecylthio)-N,N-bis(2-hydroxyethyl)acetamide (24) was prepared from the cor-
responding acyl chloride 23 via treatment with MgO as a basic reagent (Scheme 6). This
reagent provides chemoselective acylation at the nitrogen atom of diethanolamine.20 The
characteristic IR peaks of the compound were obtained at 3379 cm–1 for the OH groups
1
and at 1628 cm–1 for the C O group. The H NMR spectrum showed one doublet of
triplets at δ 3.85 ppm for the CH2CH2OH protons, a singlet at δ 3.41 ppm for the two
protons of the CH2SCH2C O group, and a broad singlet at δ 3.31 ppm for the two OH
protons. The synthesis of the three-armed 26 was accomplished by the reaction of 2-
mercaptobenzimidazole18 (12) with the ester 25 (Scheme 7). The characteristic IR peaks
Scheme 6

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
957
Scheme 7
of 26 were observed at 3244 cm–1 for the NH, at 1736 cm–1 for C O of the ester groups,
and at 1639 cm–1 for C O of the amide group. The 1H NMR spectrum showed one doublet
at δ 10.37 ppm for the NH protons, a triplet at δ 4.25 ppm for the four protons of the two
CH2–OC O groups, a doublet of triplet at δ 3.67 ppm for the N(CH2CH2)2 protons, a
singlet at δ 3.37 ppm for the CH2SCH2C O protons, and one triplet at δ 3.32 for the four
protons of the two CH2S-benzimidazole groups.
CONCLUSION
The synthesis and characterization of some novel long-chain 1,3-dipolar compounds,
isoxazolines, and thio substituted benzimidazoles is described.
EXPERIMENTAL
All the reagents and solvents used were purchased from either Merck or
Fluka Chemie and used without further purification. β-Phenylhydroxylamine and

958
A. YILDIRIM AND M. C¸ ETIN
2-mercaptobenzimidazole (12) were prepared according to the literature procedures.17,18
Silica gel plates 60 F 254, Merck-1.05554 were used for thin layer chromatography (TLC).
Column chromatography was performed using silica gel 60 (230–400 mesh). All moisture
sensitive reactions were carried out under protection with CaCl2. Air sensitive reactions
¨
were performed under N2. Melting points were determined using a BUCHI Melting Point
B-540 apparatus in open capillary tubes and are uncorrected. IR spectra (KBr or neat, ν in
cm–1) were measured on a Nicolet FTIR 6700 spectrometer. 1H NMR spectra (δ in ppm, J
in Hz) were recorded on a Varian Mercury Plus spectrometer (400 MHz) in CDCl3 using
TMS as an internal standard. The elemental analyses were performed on a EuroEA 3000
CHNS analyzer.
Supplemental Materials: IR data of all compounds can be found in “Supplemental
Materials” files of the online version of this publication.
2-(Tetradecylthio)acetic Acid (3)16
In a 250 mL two-necked flask, KOH (7.8 g, 139 mmol) was dissolved in 100 mL of
MeOH, and thioglycolic acid (2) (4.5 mL, 64.5 mmol) was dropped cautiously in over a 10-
min period. Then, 1-bromotetradecane (1) (10 mL, 36.8 mmol) was dropped slowly into the
reaction mixture with vigorous agitation. The observed slurry was stirred effectively under
N2 at room temperature (r.t.). for 1 day. The mixture was acidified with concentrated HCl,
and H2O was added. The precipitated white solid was filtered under vacuum and washed
successively with H2O. The crude product was dried at r.t. for 1 day and crystallized from
70% EtOH to afford 6.6 g (62%) of white crystalline 3; mp 68–69 ◦C (lit.16 68 ◦C).
2-(Tetradecylthio)acetyl Chloride (4)
In a 50 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube), 3 (2 g, 6.93 mmol) was dissolved in 15 mL of toluene. The flask was cooled
to 0 ◦C in an ice bath, and oxalyl chloride (1.3 mL, 15.1 mmol) was added over a 30-min
period. Then, the temperature was allowed to rise to r.t. ◦and the mixture was stirred at
this temperature for 1 h and for and additional 3 h at 70 C. Thereafter, the solvent and
the excess of oxalyl chloride were removed under vacuum. The residue was dissolved in
50 mL of petroleum ether and washed with 25 mL of ice-water. The organic phase was dried
over anhydrous Na2SO4, the solvent was removed under vacuum and the brown–orange
oily product (1.94 g, 91%) was obtained. The crude acyl chloride 4 was used in the next
step without further purification.
4-Formylphenyl 2-(Tetradecylthio)acetate (5)
In a 50 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube), 4-hydroxybenzaldehyde (0.77 g, 6.31 mmol) and NEt3 (1 mL, 7.17 mmol, 1.1
equiv.) were successively dissolved in 20 mL CH2Cl2. The flask was cooled to 0 ◦C in an
ice bath and acyl chloride 4 (1.94 g, 6.32 mmol) in 10 mL CH2Cl2 was added over a 30-min
period. Then, the temperature was allowed to rise to r.t. and the mixture was stirred at this
temperature for 2.5–3 h. After the aldehyde was consumed (checked by TLC), the organic
phase was washed successively with 2 × 25 mL H2O and dried over anhydrous Na2SO4.
The solvent was removed under vacuum to give a red–orange oily product which solidified
upon standing. This was purified by column chromatography on silica gel (petroleum

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
959
◦
1
ether-AcOEt) to afford 5 as a white crystalline solid. Yield (2.02 g, 82%); mp 49 C; H
NMR: 0.88 (t, J = 7.2, 3H, CH3), 1.32–1.25 (m, 20 H, 10 CH2), 1.41 (quin, J = 7.6, 2 H,
CH2CH2CH2CH2SCH2), 1.66 (quin, J = 7.2, 2 H, CH2CH2CH2SCH2), 2.73 (t, J = 7.6
Hz, 2 H, CH2CH2SCH2), 3.45 (s, 2 H, CH2SCH2COO), 7.31 (d, J = 8.4, 2 H, Ar-H), 7.94
(d, J = 9.2, 2 H, Ar-H), 10.01 (s, 1 H, CHO). Anal. Calcd. for C23H36O3S: C, 70.36; H,
9.24; O, 4.36; O, 12.23; S, 8.17. Found: C, 70.40; H, 9.23; O, 12.21; S, 8.16.
N-{4-[2-(Tetradecylthio)acetoxy]benzylidene}aniline Oxide (6)
In a 50 mL round-bottom flask aldehyde 5 (1.35 g, 3.44 mmol) and β-
phenylhydroxylamine (0.37 g, 3.39 mmol) were dissolved in 4 mL EtOH. The flask
was sealed and allowed to stand for 24 h in the dark. Thereafter, EtOH was evaporated
cautiously under vacuum and the residue was purified by crystallization from MeOH
◦
1
to afford 6 as a white crystalline solid. Yield: 1.0 g, 61%; mp 92–95 C; H NMR:
0.88 (t, J = 7.2, 3 H, CH3), 1.32–1.26 (m, 20 H, 10 CH2), 1.42 (quin, J = 8.0, 2 H,
CH2CH2CH2CH2SCH2), 1.67 (quin, J = 7.6, 2 H, CH2CH2CH2SCH2), 2.74 (t, J =
7.6 Hz, 2 H, CH2CH2SCH2), 3.45 (s, 2 H, CH2SCH2COO), 7.28–7.24 (m, 2 H, Ar-H),
7.53–7.47 (m, 3 H, Ar-H), 7.79–7.77 (m, 2 H, Ar-H), 7.94 (s, 1H, ON=CH), 8.47 (d,
J = 8.8, 2 H, Ar-H). Anal. Calcd. for C29H41NO3S: C, 72.01; H, 8.54; N, 2.90; O, 9.92; S,
6.63. Found: C, 71.99; H, 8.50; N, 2.93; O, 9.97; S, 6.61.
11-Bromoundecanoyl Chloride (8)
In a 50 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube) 11-bromoundecanoic acid (◦7) (9.78 g, 36.9 mmol) was dissolved in 20 mL
of toluene. The flask was cooled to 0 C in an ice bath and oxalyl chloride (6.3 mL,
73.4 mmol) was added over a 30-min period. Then, the temperature was allowed rise to r.t.
and the mixture was stirred at this temperature for 1 h and for an additional 2 h at 70 ◦C. The
residue was dissolved in 75 mL of petroleum ether and washed with 25 mL of ice-water.
The organic phase was dried over anhydrous Na2SO4 and the solvent was removed under
vacuum to yield a yellowish oily product (9.52 g, 91%). The crude acyl chloride was used
in the next step without further purification.
2-[2-(2-Methoxyethoxy)ethoxy]ethyl 11-Bromoundecanoate (9)
In a 100 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube) triethylene glycol monomethyl ether (4.9 mL, 36.01 mmol) was dissolved in
◦
20 mL CH2Cl2. The flask was cooled to 0 C in an ice bath and 8 (8.9 g, 31.38 mmol)
in 10 mL CH2Cl2 was added over a 30-min period. The temperature was allowed rise to
r.t. and the mixture was stirred at this temperature for 3 h and additionally the flask was
allowed to stand at 0–5 ◦C for 1 day. The reaction mixture was washed successively with
2 × 50 mL 10% NaHCO3 and 50 mL of brine and dried over anhydrous Na2SO4. The
solvent was removed under vacuum to yield a yellowish liquid product (12.05 g, 91%). The
purity of the product was suitable for IR spectroscopy. IR: 2924, 2854, 1733, 1533, 1504,
1455, 1350, 1244, 1104, 1042, 949, 852, 732, 641.

960
A. YILDIRIM AND M. C¸ ETIN
2-{2-[2-(Methoxyethoxy)ethoxy]}ethyl
11-(4-Formylphenoxy)undecanoate (10)
In a 100 mL round-bottom flask ester 9 (7.6 g, 18.47 mmol), K2CO3 (2.56 g, 18.52
mmol) and NaI (0.3 g, 2 mmol) were dissolved in 50 mL of anhydrous acetone. The flask
was heated in a water bath for 10–15 min under N2, and 4-hydroxybenzaldehyde (2.26 g,
18.51 mmol) was added. The mixture was heated at 50–60 ◦C for 48 h under N2. The salts
were filtered under vacuum and the solids were washed with little acetone. The filtrate was
concentrated under vacuum and the residue was dissolved in 50 mL CH2Cl2. Thereafter,
the solution was dried over anhydrous Na2SO4 and the solvent was removed on a rotary
evaporator. The obtained yellowish oily product was purified by column chromatography on
silica gel (petroleum ether-AcOEt) to afford 10 as colorless liquid. Yield: 6.02 g, 72%; 1H
NMR: 1.34–1.29 (m, 10 H, 5 CH2), 1.46 (quin, J = 7.6, 2 H, ArOCH2CH2CH2CH2CH2),
1.61 (quin, J = 7.2, 2 H, CH2CH2CH2COO), 1.81 (quin, J = 6.4, 2 H, ArOCH2CH2CH2),
2.32 (t, J = 7.2, 2 H, CH2COO), 3.38 (s, 3 H, OCH3), 3.56–3.54 (m, 2 H, OCH2CH2OCH3),
3.71–3.63 (m, 8 H, CH2OCH2CH2OCH2), 4.03 (t, J = 6.4, 2 H, ArOCH2), 4.22 (t, J =
5.2, 2 H, COOCH2), 6.99 (d, J = 8.4, 2H, Ar-H), 7.82 (d, J = 8.8, 2 H, Ar-H), 9.87 (s, 1 H,
CHO). Anal. Calcd. for C25H40O7: C, 66.35; H, 8.91; O, 24.75. Found: C, 66.41; H, 8.87;
O, 24.72.
N-[4-(12-Oxo-2,5,8,11-tetraoxadocosan-22-yloxy)benzylidene]aniline
Oxide (11)
In a 50 mL round-bottom flask 10 (0.64 g, 1.41 mmol) and β-phenylhydroxylamine
(0.16 g, 1.47 mmol) were dissolved in 5 mL of EtOH. The flask was sealed and allowed to
stand for 24 h in the dark. Thereafter, EtOH was evaporated cautiously under vacuum and
the residue was purified by column chromatography on silica gel (petroleum ether-AcOEt)
◦
1
to afford 11 as a yellow solid. Yield: 0.45 g, 57%; mp 63–65 C; H NMR: 1.30 (m,
10 H, 5 CH2), 1.47 (quin, J = 8.4, 2 H, ArOCH2CH2CH2CH2CH2), 1.62 (quin, J = 7.2,
2 H, CH2CH2CH2COO), 1.82 (quin, J = 7.2, 2 H, ArOCH2CH2CH2), 2.33 (t, J = 7.6, 2 H,
CH2COO), 3.38 (s, 3 H, OCH3), 3.56–3.54 (m, 2 H, OCH2CH2OCH3), 3.71–3.64 (m, 8 H,
CH2OCH2CH2OCH2), 4.05 (t, J = 6.4, 2 H, ArOCH2), 4.22 (t, J = 5.2, 2 H, COOCH2),
7.00–6.98 (d, J = 9.2, 2 H, Ar-H), 7.50–7.45 (m, 3 H, Ar-H), 7.84–7.79 (m, 2 H, Ar-H),
8.14 (s, 1 H, ON=CH), 8.42–8.40 (d, J = 8.8, 2 H, Ar-H). Anal. Calcd. for C31H45NO7: C,
68.48; H, 8.34; N, 2.58; O, 20.60. Found: C, 68.54; H, 8.33; N, 2.52; O, 20.61.
2-[2-(2-Methoxyethoxy)ethoxy]ethyl
11-(1H-Benzo[d]imidazole-2-ylthio)undecanoate (13)
In a 50 mL round-bottom flask 9 (1.2 g, 2.92 mmol), K2CO3 (0.35 g, 2.53 mmol)
and NaI (0.05 g, 0.3 mmol) were dissolved in 15 mL of anhydrous acetone. The flask was
heated in a water bath for 10–15 min under N2, and 1218 (0.4 g, 2.66 mmol) was added.
◦
The mixture was heated at 50–60 C for 7 h and for an additional 1 day at r.t. under N2.
Acetone was removed under vacuum and the residue was dissolved in 25 mL CHCl3. The
organic phase was washed with 20 mL H2O and the aqu. phase was extracted once with
a small amount CHCl3. The combined organic phases were dried over anhydrous Na2SO4
and the solvent was removed on a rotary evaporator. The yellowish residue was purified
by column chromatography on silica gel (petroleum ether-AcOEt-MeOH) to afford 13 as

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
961
a yellowish oily product. Yield: 1.26 g, 98%; 1H NMR: 1.41–1.22 (m, 12 H, 6 CH2), 1.59
(quin, J = 7.2, 2 H, CH2CH2C O), 1.71 (quin, J = 7.2, 2 H, SCH2CH2CH2), 2.30 (t,
J = 8, 2 H, CH2C O), 3.37 (s, 3 H, OCH3), 3.42 (t, J = 5.2, 2 H, N2CSCH2), 3.56–3.54
(m, 2 H, OCH2CH2OCH3), 3.70–3.64 (m, 8 H, CH2OCH2CH2OCH2), 4.22 (t, J = 5.2,
2 H, CH2OC O), 7.28–7.23 (m, 2 H, Ar-H), 7.63–7.58 (m, 2 H, Ar-H). Anal. Calcd. for
C25H40N2O5S: C, 62.47; H, 8.39; N, 5.83; O, 16.64; S, 6.67. Found: C, 62.51; H, 8.32; N,
5.85; O, 16.70; S, 6.62.
Undec-10-en-1-ol (15)
To an ice-cooled suspension of LiAlH4 (2.5 g, 65.9 mmol) in 100 mL of THF, 10-
undecenoic acid (14) (5 g, 27.1 mmol) in (50 mL) of THF was added dropwise over 30 min
(protected by a CaCl2 guard tube). Then, the mixture was stirred at 50 ◦C for 2 h and for
another 1 day at r.t. After cooling in an ice bath, 50 mL of AcOEt and 200 mL H2O were
added cautiously. The mixture was acidified with 2M HCl and extracted with 3 × 50 mL
of ether. The organic phase was washed successively with H2O and brine and dried over
anhydrous Na2SO4. The solvent was removed on a rotary evaporator. The colorless residue
was purified by column chromatography on silica gel (petroleum ether-AcOEt) to afford
15 as a colorless liquid. Yield: 4 g, 88%; 1H NMR: 1.38–1.29 (m, 12 H, 6 CH2), 1.56 (quin,
J = 6.4, 2 H, CH2CH2CH2OH), 1.70 (bs, 1 H, OH), 2.07–2.01 (m, 2 H, CH2 CHCH2),
3.64 (t, J = 7.2, 2 H, CH2OH), 5.02–4.91 (m, 2 H, CH2 CHCH2), 5.86–5.76 (m, 1 H,
CH2 CHCH2). Anal. Calcd. for C11H22O: C, 77.58; H, 13.02; O, 9.40. Found: C, 77.64;
H, 12.98; O, 9.38.
9-(3-Phenyl-4,5-dihydroisoxazol-5-yl)nonan-1-ol (17)
In a 50 mL two-necked flask fitted with a reflux condenser 15 (1 g, 5.87 mmol),
0.08 mL of NEt3 and 7 mL solution of 6–14% NaOCl were mixed in 15 mL CH2Cl2. The
flask was cooled to 1–2 ◦C, and benzaldoxime (0.76 g, 6.27 mmol) in 10 mL CH2Cl2 was
dropped in over 30 min. The resulting two-phased mixture was stirred at 1–2 ◦C for 2 h and
for an additional 3 h at r.t. The organic phase was separated and the aqu. phase was extracted
with 3 × 10 mL CH2Cl2. The organic phases were combined and washed with 20 mL H2O
and dried over anhydrous Na2SO4. The solvent was removed on a rotary evaporator and
a yellowish wax solid was obtained. The crude product was crystallized from MeOH and
washed with cold petroleum ether to afford 17 as white leaf-like crystals. Yield: 1.5 g,
88%; mp 93–94 ◦C; 1H NMR: 1.66–1.31 (m, 16 H, 8 CH2), 1.71 (bs, 1 H, OH), 2.96 (dd,
J1 = 8.4, J2 = 16.4, 1 H, C4H), 3.39 (dd, J1 = 10.4, J2 = 16.4, 1 H, C4H), 3.64–3.63
(m, 2 H, CH2CH2OH), 4.77–4.69 (m, 1 H, C5H), 7.41–7.38 (m, 3 H, Ar-H), 7.69–7.65 (m,
2 H, Ar-H),. Anal. Calcd. for C18H27NO2: C, 74.70; H, 9.40; N, 4.84; O, 11.06. Found: C,
74.76; H, 9.36; N, 4.85; O, 11.03.
9-(3-Phenyl-4,5-dihydroisoxazol-5-yl)nonanal (18)
In a 50 mL round-bottom flask isoxazoline 17 (0.37 g, 1.28 mmol) was dissolved in
30 mL CH2Cl2. Then, pyridinium chlorochromate (1.2 g, 5.57 mmol) and NaOAc (0.33 g,
4.02 mmol) were added. The resulting mixture was stirred at r.t. for 3 h and celite (2 g)
was added. The suspension was filtered under vacuum and passed through a short silica
gel packed column. The solvent was removed and the residue was purified by column

962
A. YILDIRIM AND M. C¸ ETIN
chromatography on silica◦gel (petroleum ether-AcOEt) to afford 18 as a white solid. Yield:
1
0.28 g, 76%; mp 66–68 C; H NMR: 1.82–1.32 (m, 14 H, 7 CH2), 2.45–2.40 (m, 2 H,
CH2CHO), 2.97 (dd, J1 = 8.4, J2 = 16.6, 1 H, C4H), 3.40 (dd, J1 = 10, J2 = 16.4, 1 H,
C4H), 4.77–4.69 (m, 1 H, C5H), 7.42–7.38 (m, 3 H, Ar-H), 7.69–7.65 (m, 2 H, Ar-H), 9.76
(t, J = 2, 1 H, CHO). Anal. Calcd. for C18H25NO2: C, 75.22; H, 8.77; N, 4.87; O, 11.13
Found: C, 75.23; H, 8.71; N, 4.91; O, 11.15.
9-(3-Phenyl-4,5-dihydroisoxazol-5-yl)nonyl 2-Chloroacetate (20)
In a 50 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube), isoxazoline 17 (0.4 g, 1.38 mmol) and◦NEt3 (0.2 mL, 1.44 mmol, 1 equiv.)
were dissolved in 15 mL CH2Cl2 and cooled to 0 C. Chloroacetyl chloride (0.11 mL,
1.42 mmol) in 5 ◦mL CH2Cl2 was added dropwise over 15 min. The resulting mixture was
stirred at 10–15 C for 2 h. After the consumption of the isoxazoline (checked by TLC),
the reaction mixture was washed successively with 2 × 15 mL of 5% Na2CO3 and 15 mL
H2O. The organic phase was dried over anhydrous Na2SO4, and the solvent was removed
on a rotary evaporator. A white wax solid product (0.5 g, 99%) was obtained. The crude
chloroacetylated isoxazoline 20 was used in the next step without further purification.
9-(3-Phenyl-4,5-dihydroisoxazol-5-yl)nonyl
2-(1H-benzo[d]imidazol-2-ylthio)acetate (21)
In a 50 mL round-bottom flask, 20 (0.5 g, 1.37 mmol), K2CO3 (0.3 g, 2.17 mmol),
and NaI (0.02 g, 0.13 mmol) were dissolved in 15 mL of anhydrous acetone. The flask
was heated in water bath for 10–15 min under N2 and 12 (0.21 g, 1.40 mmol) was added.
Thereafter, the mixture was heated at 50–60 ◦C for 2 h. CH2Cl2 (10 mL) was added to the
red–brown solution and the resulting salts were filtered. The solvent was removed under
vacuum and the residue was purified by column chromatography on silica gel (petroleum
ether-CH2Cl2) to afford 21 as a yellowish–orange solid. Yield: 0.5 g, 76%; mp 101–102
◦C; 1H NMR: 1.35–1.28 (m, 10 H, 5CH2), 1.69–1.58 (m, 4 H, 2CH2), 2.97 (dd, J1 = 8.4,
J2 = 16.8, 1 H, C4H), 3.40 (dd, J1 = 10, J2 = 16.4, 1 H, C4H), 3.95 (s, 2H, –SCH2COO–),
4.20 (t, J = 6.8 Hz, 2H, –COOCH2–), 4.78–4.70 (m, 1H, C5H), 7.22 (sext, J = 3.2, 2 H, Ar-
H), 7.41–7.39 (m, 4 H, Ar-H), 7.68–7.66 (m, 3 H, Ar-H). Anal. Calcd. for C27H33N3O3S:
C, 67.61; H, 6.93; N, 8.76; O, 10.01; S, 6.69. Found: C, 67.68; H, 6.90; N, 8.70; O, 9.97;
S, 6.75.
2-(Dodecylthio)acetic Acid (22)
This compound was prepared according to procedure given for compound 3. The
crude product was dried at r.t. for 1 day and crystallized from 70% EtOH to afford 22 with
62% yield as a white crystalline compound; mp 57–59 ◦C (lit.21 61–62 ◦C).
2-(Dodecylthio)acetyl Chloride (23)
This compound was prepared according to procedure given for compound 4. The
solvent was removed under vacuum and a yellowish oily product was obtained (91%
yield). The crude acyl chloride 23 was used in the next step without further purification.

C,N-DIPHENYL NITRONES, ISOXAZOLINES, AND MERCAPTOBENZIMIDAZOLES
963
2-(Dodecylthio)-N,N-bis(2-hydroxyethyl)acetamide (24)
This compound was synthesized according to procedure given by Kim et al.20 from
(3.64 g, 13.05 mmol) of 23. After crystallization from 30 mL of petroleum ether/acetone
(5/1), 24 was obtained as a colorless white product (yield: 3.85 g, 85%); mp 51–52.5 ◦C;
1H NMR: 0.88 (t, J = 7.2, 3 H, CH3), 1.38–1.26 (m, 18 H, 9 CH2), 1.61 (quin, J = 7.6,
CH2CH2SCH2C O), 2.64 (t, J = 7.6, 2 H, CH2SCH2C O), 3.31 (bs, 2 H, 2 OH), 3.41
(s, 2 H, CH2SCH2C O), 3.57 (q, J = 4.8, 4 H, 2 CH2CH2OH), 3.85 (dt, J1 = 20.4, J2 =
5.2, 4 H, 2 CH2CH2OH),. Anal. Calcd. for C18H37NO3S: C, 62.20; H, 10.73; N, 4.03; O,
13.81; S, 9.23. Found: C, 62.24; H, 10.71; N, 3.96; O, 13.84; S, 9.25.
{[2-(Dodecylthio)acetyl]azanediyl}bis(ethane-2,1-diyl)
bis(11-bromoundecanoate) (25)
In a 50 mL two-necked flask fitted with a reflux condenser (protected by a CaCl2
guard tube), amide 24 (1.02 g, 2.93 mmol) and NEt3 (0.85 mL) were dissolved in 15 mL
CH2Cl2 and cooled to 0 ◦C. 11-Bromoundecanoyl chloride (8) (1.68 g, 5.92 mmol) in 10 mL
CH2Cl2 was added dropwise over 30 min. The mixture was stirred at r.t. for one night.
The reaction mixture was washed successively with H2O, dried over anhydrous Na2SO4
and the solvent was removed on a rotary evaporator. The residue was purified by column
chromatography on silica gel (petroleum ether-AcOEt) to afford 25 as a white waxy solid.
Yield: 1.55 g, 61%; 1H NMR: 0.88 (t, J = 7.6, 3 H, CH3), 1.44–1.26 (m, 42 H, 9 CH2 and
12 CH2), 1.60 (quin, J = 7.2, 6 H, CH2CH2SCH2C O and OC OCH2CH2), 1.85 (quin,
J = 7.6, 4 H, 2 CH2CH2CH2Br), 2.33–2.28 (m, 4 H, OC OCH2CH2), 2.62 (t, J = 7.6, 2
H, CH2CH2SCH2C O), 3.35 (s, 2 H, CH2SCH2C O), 3.41 (t, J = 6.8, 4 H, 2 CH2Br),
3.65 (dt, J1 = 31.2, J2 = 5.6, 4 H, N(CH2CH2)2), 4.23 (t, J = 5.6, 4 H, 2 CH2OC O).
Anal. Calcd. for C40H75Br2NO5S: C, 57.06; H, 8.98; N, 1.66; S, 3.81. Found: C, 57.01; H,
9.00; N, 1.68; S, 3.84.
{[2-(Dodecylthio)acetyl]azanediyl}bis(ethane-2,1-diyl)
bis-11-(benzimidazole-2-ylthio)undecanoate (26)
In a 50 mL round-bottom flask under N2 atmosphere, 2-mercaptobenzimidazole (12)
(0.54 g, 3.56 mmol) and K2CO3 (1 g, 7.24 mmol) were dissolved in 30 mL of anhydrous
acetone and heated in a water bath for 15 min. Thereafter, NaI (0.03 g, 0.2 mmol) and 1.5 g,
1.78 mmol of amide 25 were added to the flask and heated for 20 h. The warm solution
was filtered and the solvent was removed under vacuum. H2O, EtOH, and a small amount
of AcOEt were added to the oily residue. After storage at r.t. for a period of time, the
precipitated white solid was filtered and dried at r.t. It was crystallized from EtOH to yield
26 (1.3 g, 74%); mp 75 ◦C; 1H NMR: 0.88 (t, J = 7.2, 3 H, CH3), 1.41–1.24 (m, 42 H, 9
CH2 and 12 CH2), 1.59 (quin, J = 7.2, 6 H, CH2CH2SCH2C O and OC OCH2CH2), 1.74
(quin, J = 7.6, 4 H, 2 CH2CH2S-benzimidazole), 2.33–2.28 (m, 4 H, OC OCH2CH2),
2.62 (t, J = 7.6, 2 H, CH2CH2SCH2C O), 3.32 (t, J = 7.2, 4 H, 2 CH2S-benzimidazole),
3.37 (s, 2 H, CH2SCH2C O), 3.67 (dt, J1 = 23.2, J2 = 5.6, 4 H, N(CH2CH2)2), 4.25 (t,
J = 5.2, 4 H, 2 CH2OC O), 7.33 (d, J = 7.6, 4 H, Ar-H), 7.67 (d, J = 6.8, 4 H, Ar-H),
10.37 (d, J = 14, 2 H, NH). Anal. Calcd. for C54H87N5O5S3: C, 66.01; H, 8.93; N, 7.13; S,
9.79. Found: C, 65.98; H, 8.95; N, 7.14; S, 9.75.

964
A. YILDIRIM AND M. C¸ ETIN
REFERENCES
1. Oude Alink, B. A. M. In: R. W. Johnson, E. Fritz (Eds.), Fatty Acids in Industry; Marcel Dekker:
New York, 1989; pp. 407-429.
2. Yıldırım, A.; C¸ etin, M. Monatsh. Chem. 2008, 139, 1279-1283.
3. Yıldırım, A.; C¸ etin, M. Corros. Sci. 2008, 50, 155-165.
4. Chebabe, D.; Chikh, Z. A.; Dermaj, A.; Rhattas, K.; Jazouli, T.; Hajjaji, N.; El-Mdari, F.; Srhiri,
A. Corros. Sci. 2004, 46, 2701-2713.
5. Song, S. X.; Zhang, H. L.; Kim, C. G.; Sheng, L.; He, X. P.; Long, Y. T.; Li, J.; Chen, G. R.
Tetrahedron 2010, 66, 9974-9980.
6. Ravichandran, R. U.S. Patent 4 898 901, 1990, 8 pp.
7. Young, W. R.; Haller, I.; Aviram, A. IBM J. Res. Develop. 1971, 15, 41-51.
8. Gella, C.; Ferrer, E.; Alibes, R.; Busque, F.; de March, P.; Figueredo, M.; Font, J. J. Org. Chem.
2009, 74, 6365-6367.
9. Cicchi, S.; Marradi, M.; Goti, A.; Brandi, A. Tetrahedron Lett. 2001, 42, 6503-6505.
10. Bru¨ning, I.; Grashey, R.; Hauck, H.; Huisgen, R.; Seidl, H. Org. Synth. 1966, 46, 96.
11. Zhang, L. H.; Chung, J. E.; Costello, T. D.; Valvis, I.; Ma, P.; Kauffman, S.; Ward, R. J. Org.
Chem. 1997, 62, 2466-2470.
12. Kenar, J. A.; Sevim, Z. E. J. Am. Oil Chem. Soc. 2001, 78, 1045-1050.
13. Klimesova, V.; Koci, J.; Pour, M.; Stachel, J.; Waisser, K.; Kaustova, J. Eur. J. Med. Chem. 2002,
37, 409-418.
14. Seredenin, S. B.; Blednov, J. A.; Saveliev, V. L.; Mozhaeva, T. Y.; Orlova, E. K.; Ragimov,
K. S. O.; Yarkova, M. A.; Chichkanov, G. G.; Kaverina, N. V.; Tsorin, I. B.; Kirsanova, G. J.;
Neznamov, G. G. U.S. Patent 6 376 666, 2002, 26 pp.
15. Humenyuk, O. L.; Syza, O. I.; Krasovs’kyi, O. M. Mater. Sci. 2007, 43, 91-101.
16. Berge, R.; Songstad, J. U.S. Patent 6 046 237, 2000, 7 pp.
17. Kamm, O. Org. Synth. 1925, 4, 57.
18. VanAllan, J. A.; Deacon, B. D. Org. Synth. 1950, 30, 56.
19. Hassner, A.; Lokanatha, R. K. M. Synthesis 1989, 57-59.
20. Kim, D. H.; Rho, H. S.; You, J. V.; Lee, J. C. Tetrahedron Lett. 2002, 43, 277-279.
21. Rapoport, L.; Smith, A.; Newman, M. S. J. Am. Chem. Soc. 1947, 69, 693-694.