Efficient esterification of long chain aliphatic carboxylic acids with alcohols over ZrOCl2·8H2O catalyst

Article abstract of DOI:10.1055/s-2005-869951

Direct condensation of equimolar amounts of long chain carboxylic acids and alcohols could be achieved by using zirconyl chloride as an efficient catalyst. ZrOCl₂·SH₂O showed high activity for esterification between primary acids and alcohols; however, it was less active in the combination of branched acid and secondary alcohols to give the corresponding esters. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-2005-869951

PAPER
1939
Efficient Esterification of Long Chain Aliphatic Carboxylic Acids with
Alcohols over ZrOCl2·8H2O Catalyst
Esterification of
L
s
ong
C
hain
h
A
liphatic
C
u
a
rboxylic Ac
d
ids iram Mantri, Kenichi Komura, Yoshihiro Sugi*
Department of Materials Science and Technology, Faculty of Engineering, Gifu University, Yanagido, 1-1, Gifu 501-1193, Japan
Fax +81(58)2932597; E-mail: sugi@apchem.gifu-u.ac.jp
Received 17 January 2005; revised 15 March 2005
cants for plastics; paint and ink additives and for mechan-
ical processing; personal care emollients; surfactants and
base materials for perfumery; etc. They are also used as
solvents or co-solvents, and oil carrier in agricultural in-
Abstract: Direct condensation of equimolar amounts of long chain
carboxylic acids and alcohols could be achieved by using zirconyl
chloride as an efficient catalyst. ZrOCl2·8H2O showed high activity
for esterification between primary acids and alcohols; however, it
was less active in the combination of branched acid and secondary dustry.
alcohols to give the corresponding esters.
To the best of our knowledge, there has been no promising
Key words: esterification, long chain aliphatic carboxylic acid,
long chain aliphatic alcohol, zirconyl chloride
method in the combination of ‘long chain acids and long
chain alcohols’ although many homogeneous and hetero-
geneous catalysts have been developed for the esterifica-
tion of carboxylic acid with an equal amount of alcohols.10
This situation of the esters prompted us to examine the
‘green’ synthesis of esters with long chain carboxylic ac-
ids and alcohols, both of which carbon number are higher
than 10. In this paper, we describe the direct condensation
of long chain carboxylic acids and alcohols using
ZrOCl2·8H2O as catalyst, as exemplified for palmitic acid
with cetyl alcohol in Scheme 1.
The esterification of carboxylic acids with alcohols is an
important fundamental process in organic synthesis.1,2
Homogeneous acid catalysts (viz. mineral acids) and
Lewis acids like Sn-octoate are well-known for the pur-
pose.3 In most of the esterification methods, large amount
of catalyst and large excess of either carboxylic acids or
alcohols are essential to achieve the high yield of esters,
and tedious work-up procedures are required to get reac-
tion products.4 It is not of practical interest to use large
amount of catalyst and condensing reagents to promote
green chemistry. Hence, there is a need to develop an en-
vironmentally benign method for esterification.
O
OH
+
OH
Many attempts to find solid acid catalysts were done dur-
ing decades; however, the success of the catalysis was
limited to esters less than C10 in either carboxylic acid or
alcohols. Ramu and his co-workers reported the esterifica-
tion of palmitic acid with methanol over tungsten oxide
supported on zirconia,5 and decanoic acid with methanol
over modified montmorillonite catalyst was also devel-
oped by Kaneda and co-workers.6 Saroja and Kaimol de-
scribed that the fatty acids was converted to their esters
via acyl bromides.7
ZrOCl2⋅8H2O
– H2O
O
O
Scheme 1
The esterification of palmitic acid with cetyl alcohol was
carried out at various conditions to optimize the reaction
conditions in this study regarding the amount of catalyst,
removal of water from the system, solvents, and reaction
temperature. Table 1 shows the effects of types of high
boiling aromatic hydrocarbons as solvent in the esterifica-
tion of palmitic acid with cetyl alcohol. Water formed by
the esterification was easy to remove as azeotropic mix-
ture of a high boiling solvent. The conversion of palmitic
acid was increased with increasing the boiling points of
aromatic hydrocarbon in the order: benzene < toluene <<
m-xylene < mesitylene < diethylbenzenes < tetralin at
their azeotropic reflux conditions. The reaction in benzene
and toluene was slow at their reflux conditions; however,
high boiling solvent such as m-xylene, mesitylene, dieth-
ylbenzenes, and tetralin gave moderate to excellent con-
version to esters. From these results, we chose mesitylene
as the standard solvent.
Very recently, Yamamoto and co-workers reported the di-
rect ester condensation of equimolar carboxylic acids and
alcohols using Hf(IV) and Zr(IV) chlorides.8 Bartoli and
co-workers also described Zn(ClO4)2·8H2O-catalyzed
condensation of nearly equimolar amount of acids and al-
cohols without solvent.9 The characteristics of these cata-
lysts are their ease of recyclization and reusability,
because these metal salts are spontaneously separated
from the products solution after the esterification reaction.
Fatty acid esters are used as raw materials of emulsifiers
or oiling agents for foods, spin finishes and textiles; lubri-
SYNTHESIS 2005, No. 12, pp 1939–1944
x
x.
x
x
.
2
0
0
5
Advanced online publication: 20.06.2005
DOI: 10.1055/s-2005-869951; Art ID: F01005SS
© Georg Thieme Verlag Stuttgart · New York

1940
K. Mantri et al.
PAPER
Table 1 Effects of Reaction Temperature on the Conversion of
Table 3 Esterification of Primary Carboxylic Acids with Primary
Palmitic Acid in the Esterification with Cetyl Alcohola
Alcohols of Different Chain Lengthsa
Entry Solvent
Reaction temperature Conversion
Entry Acid
Alcohol
Yield (%)
>99.9
>99.9
90.5
(°C)
(%)
1
2
palmitic acid
capryl alcohol
lauryl alcohol
myristyl alcohol
cetyl alcohol
stearyl alcohol
cetyl alcohol
cetyl alcohol
cetyl alcohol
cetyl alcohol
cetyl alcohol
1
2
3
4
5
6
benzene
80
4.3
palmitic acid
palmitic acid
palmitic acid
palmitic acid
capric acid
toluene
110
140
162
182
207
11.8
48.6
86.2
99.6
3
m-xylene
mesitylene
diethylbenzenes
tetralin
4
86.2
5
85.3
6
>99.9
99.9
100
7
lauric acid
a Reaction conditions: substrates: palmitic acid (6 mmol), cetyl alco-
hol (6 mmol); catalyst: ZrOCl2·8H2O (0.12 mmol); solvent: 40 mL;
reaction time: 24 h.
8
myristic acid
palmitic acid
stearic acid
99.5
9
86.2
The effect of catalyst amount on the yield of cetyl palmi-
tate in the esterification of palmitic acid with cetyl alcohol
were studied by varying the amount of ZrOCl2·8H2O from
0.02 mmol to 0.20 mmol. The yield of the ester gradually
increased with increasing the amount of the catalyst
(Table 2). However, the increase of yield of the ester was
not so drastic for 24 hours of reaction time. From these re-
sults, we chose the standard conditions for further re-
search: 0.12 mmol of ZrOCl2·8H2O against 6 mmol of
acid and alcohol at the reflux temperature of mesitylene.
10
83.3
a Reaction conditions: substrates: acid (6 mmol), alcohol (6 mmol);
catalyst: ZrOCl2·8H2O (0.12 mmol); solvent: mesitylene (40 mL); re-
action temperature: 162 °C; reaction time: 24 h.
(Table 3, entries 1–5). Similarly, the yield of the ester
with cetyl alcohol decreased with increasing carbon num-
ber of aliphatic carboxylic acids in the following order:
C10 @ C12 @ C14 > C16 > C18 (Table 3, entries 6–10). These
results show that ZrOCl2·8H2O is very effective catalysts
for the esterification of long chain fatty carboxylic acids
and alcohols.
Table 2 Effects of the Amount of ZrOCl2·8H2O on the Yield of
Cetyl Palmitate in the Esterification of Palmitic Acid with Cetyl Al-
cohola
Table 4 shows the esterification of palmitic acid with sec-
ondary alcohols and of isostearic acid (2-heptylundecano-
ic acid) with primary and secondary alcohols. The
esterification of palmitic acid with secondary alcohols
was slower than in the case of primary acid and alcohols.
The esterification of palmitic acid with decan-2-ol and
dodecan-1-ol gave good yield; however, the yield of the
palmitate decreased gradually with increasing the chain
length of secondary alcohols (Table 4, entries 1–4). The
esterification of isostearic acid with primary alcohols was
much slower than the cases of palmitic acid (Table 3, en-
tries 1–5); however, the isostearates was obtained in mod-
erate yield of 30–40% (Table 4, entries 5–10). The yield
of the esters could be increased by increasing the catalyst
amount and reaction temperature (Table 4, entry 9). The
esterification of isosteraic acid with secondary alcohols
was much slower than the cases with primary alcohols
(Table 4, entries 11–15), and the yields of the esters were
less than 10%, although they increased with increase of
the catalyst amount at higher temperature. These results
show that catalytic activity of ZrOCl2·8H2O is not high
enough to synthesize these esters in the esterification of
palmitic and isostearic acids with secondary alcohols. The
improvement of the catalytic activity of ZrOCl2·8H2O for
these syntheses is essential, and will be described in the
near future.
Entry
ZrOCl2·8H2O
(mmol)
Substrate/Catalyst
(molar ratio)
Yield
(%)
1
2
3
4
5
0.02
0.06
0.12
0.15
0.2
300
100
50
15.9
54.8
86.2
92.6
99.5
40
30
a Reaction conditions: substrates: palmitic acid (6 mmol), cetyl alco-
hol (6 mmol); solvent: mesitylene (40 mL); reaction temperature: 162
°C; reaction time: 24 h.
Table 3 summarizes typical results of the condensation of
primary long chain carboxylic acids and primary long
chain alcohols of different chain lengths (C10 to C18) at
162 °C using mesitylene as solvent for 24 h. Table 3 (en-
tries 1–5) revealed that the yields of the esters decreased
with increasing carbon number of alcohols for the esteri-
fication with palmitic acid. Complete conversion of palm-
itic acid was observed in the case of reaction with capryl
and lauryl alcohol. The yields of the esters with palmitic
acid increased with increasing carbon number of alcohols
in the following order: C10 > C12 > C14 > C16 > C18
Synthesis 2005, No. 12, 1939–1944 © Thieme Stuttgart · New York

PAPER
Esterification of Long Chain Aliphatic Carboxylic Acids
1941
ZrOCl2·8H2O was purchased from Kanto Chemical Co. Inc., Japan.
Stearic acid (octadecanoic acid), stearyl alcohol (octadecan-1-ol),
palmitic acid (hexadecanoic acid), cetyl alcohol (hexadecan-1-ol),
myristic acid (tetradecanoic acid), myristyl alcohol (tetradecan-1-
ol), lauric acid (dodecanoic acid), lauryl alcohol (dodecan-1-ol), ca-
pric acid (decanoic acid), capryl alcohol (decan-1-ol), isostearic
acid (2-heptylundecanoic acid), tetradecan-2-ol, dodecan-2-ol, and
decan-2-ol were purchased from Tokyo Kasei Kogyo Co. Ltd., Ja-
pan. Oleic acid [(Z)-9-octadecenoic acid], elaidic acid [(E)-9-octa-
decenoic acid], and linoleic acid [(Z,Z)-9,12-octadecandienoic acid]
were purchased from Sigma-Aldrich Inc. Hexadecan-2-ol was re-
ceived from Acros Organics. m-Xylene, mesitylene, and tetralin
were purchased from Nacalai Tesque, Japan. Diethylbenzenes (o/m/
p = 5:66:29; average ethyl number in benzene ring = 2.014) was
supplied from Nippon Steel Chemicals Ltd. All chemicals were
used without further purifications. The products yields were ana-
lyzed by gas chromatography [Shimadzu Gas Chromatograph 14A,
Ultra-1 (25 m × 0.3 mm) capillary column] equipped with FID. 1H
and 13C NMR spectra were recorded at 400 and 100 MHz, respec-
tively, on a Varian Inova 400 spectrometer. IR spectra were record-
ed on a Nexus 470 (Thermo Nicolet) FT-IR spectrometer by KBr
technique as in solid and neat as in liquid. Elemental analyses of all
esters were entrusted to measure at Center for Organic Elemental
Microanalysis, Kyoto University.
Table 4 Esterification of Palmitic Acid with Secondary Alcohols,
and Isosetearic Acid with Primary and Secondary Alcoholsa
Entry Acid
Alcohol
Yield (%)
1
2
palmitic acid
decan-2-ol
71
palmitic acid
palmitic acid
palmitic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
isostearic acid
dodecan-2-ol
tetradecan-2-ol
hexadecan-2-ol
capryl alcohol
lauryl alcohol
myristyl alcohol
cetyl alcohol
cetyl alcohol
stearyl alcohol
decan-2-ol
60
3
41
4
33
5
42
6
35
7
34
8
31
9
86b
10
11
12
13
14
15
29
7
decan-2-ol
29c
Esterification of Long Chain Carboxylic Acids with Alcohols;
General Procedure
dodecan-2-ol
tetradecan-2-ol
hexadecan-2-ol
5
The esterification was carried out in a single-necked, round-bot-
tomed flask (100 mL) equipped with a Teflon-coated magnetic stir-
ring bar and a Dean–Stark apparatus surmounted with a reflux
condenser. Equimolar of each of the substrates (long chain primary
alcohols and acids) (6 mmol) and ZrOCl2·8H2O (0.12 mmol) in 40
mL of solvents (benzene, toluene, m-xylene, mesitylene, diethyl-
benzenes and tetralin) were charged into the round-bottomed flask.
The mixture was heated to reflux temperature with continuous re-
moval of H2O generated from the reaction. After 24 h, the tempera-
ture of the resulting reaction mixture was cooled down to r.t., and
the catalyst was separated from the reaction mixture by filtration.
The aliquots were analyzed by GC to determine the conversion and
product yield. The purification of the products was done by column
chromatography using silica gel (70–230 mesh) eluting with 10%
EtOAc in hexane.
6
no reactiond
a Reaction conditions: substrates: palmitic acid or isostearic acid (6
mmol), alcohol (6 mmol); catalyst: ZrOCl2·8H2O (0.12 mmol); sol-
vent: mesitylene (40 mL), reaction temperature: 162 °C; reaction
time: 24 h.
b Solvent: diethylbenzenes (40 mL), catalyst: ZrOCl2·8H2O (0.6
mmol); reaction temperature: 180 °C.
c Solvent: diethylbenzenes (40 mL), catalyst: ZrOCl2·8H2O (1 mmol);
reaction temperature: 180 °C.
d Catalyst: ZrOCl2·8H2O (0.6 mmol).
Table 5 Esterification of Unsaturated Acids with Cetyl Alcohola
Decyl Palmitate
IR (KBr): 1731 cm–1.
Entry
Acids
Yield (%)
>99.9
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 6 H), 1.26 (br s, 38 H),
1.58–1.63 (br m, 4 H), 2.27–2.31 (t, J = 7.5 Hz, 2 H), 4.04–4.07 (t,
J = 6.6 Hz, 2 H).
13C NMR (100 MHz, CDCl3): d = 14.11, 22.67, 25.03, 25.93, 28.65,
29.16, 29.25, 29.27, 29.30, 29.36, 29.47, 29.53, 29.60, 29.64, 29.68,
31.89, 31.92, 34.42, 64.40, 174.04.
1
2
3
oleic acid
elaidic acid
linoleic acid
>99.9
70.1
a Reaction conditions: substrates; acids (2 mmol), cetyl alcohol (2
mmol); catalyst: ZrOCl2·8H2O (0.04 mmol); solvent: mesitylene (30
mL), reaction temperature: 162 °C; reaction time: 24 h.
Anal. Calcd for C26H52O2: C, 78.72; H, 13.21. Found: C, 79.02; H,
12.96.
Lauryl Palmitate
The results of the esterification of unsaturated fatty acids
such as oleic, elaidic, and linoleic acids with cetyl alcohol
are shown in Table 5. The complete conversion with very
high yields of the esters was achieved in the esterification
of oleic and elaidic acid with cetyl alcohol in 24 hours;
however, linoleic acid gave the ester in a lower yield.
These esterifications occurred without any isomerization,
and kept the configuration of double bond.
IR (KBr): 1732 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.89 (br m, 6 H), 1.25–1.29
(br s, 42 H), 1.59–1.62 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
13C NMR (100 MHz, CDCl3): d = 14.32, 22.91, 25.26, 26.16, 28.88,
29.39, 29.48, 29.50, 29.58, 29.59, 29.70, 29.76, 29.80, 29.83, 29.86,
29.88, 29.92, 32.15, 34.63, 64.60, 174.22.
Anal. Calcd for C28H56O2: C, 79.18; H, 13.29. Found: C, 79.17; H,
13.52.
Synthesis 2005, No. 12, 1939–1944 © Thieme Stuttgart · New York

1942
K. Mantri et al.
PAPER
Myristyl Palmitate
13C NMR (100 MHz, CDCl3): d = 14.33, 22.91, 25.26, 26.16, 28.88,
29.39, 29.48, 29.50, 29.58, 29.70, 29.76, 29.80, 29.83, 29.87, 29.90,
29.92, 34.64, 64.61, 174.24.
IR (KBr): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.89 (br m, 6 H), 1.25–1.30
(br s, 46 H), 1.59–1.65 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C30H60O2: C, 79.58; H, 13.36. Found: C, 79.31; H,
13.39.
13C NMR (100 MHz, CDCl3): d = 14.33, 22.92, 25.26, 26.17, 28.88,
29.39, 29.49, 29.50, 29.59, 29.71, 29.76, 29.81, 29.83, 29.88, 29.91,
29.92, 32.15, 34.63, 64.61, 174.22.
Cetyl Stearate
IR (KBr): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.89 (br m, 6 H), 1.22–1.29
(br s, 54 H), 1.56–1.62 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C30H60O2: C, 79.58; H, 13.36. Found: C, 79.53; H,
13.66.
Cetyl Palmitate
13C NMR (100 MHz, CDCl3): d = 14.11, 22.68, 25.03, 25.93, 28.64,
29.15, 29.25, 29.27, 29.35, 29.47, 29.52, 29.57, 29.60, 29.65, 29.69,
31.92, 34.41, 64.39, 174.02.
IR (KBr): 1734 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.86–0.89 (br m, 6 H), 1.24–1.30
(br s, 50 H), 1.55–1.65 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C34H68O2: C, 80.24; H, 13.47. Found: C, 80.08; H,
13.76.
13C NMR (100 MHz, CDCl3): d = 14.33, 22.92, 25.26, 26.17, 28.88,
29.39, 29.49, 29.50, 29.59, 29.70, 29.76, 29.80, 29.83, 29.88, 29.92,
32.15, 34.64, 64.61, 174.24.
Decyl Isostearate
IR (film): 1728 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 6 H), 1.19 (d, J = 6.2
Hz, 3 H), 1.25–1.30 (br s, 44 H), 1.38–1.48 (br m, 4 H), 1.56–1.61
(br m, 4 H), 2.25–2.30 (m, 2 H), 4.89–4.94 (m, 1 H).
Anal. Calcd for C32H64O2: C, 79.93; H, 13.41. Found: C, 80.02; H,
13.45.
Stearyl Palmitate
13C NMR (100 MHz, CDCl3): d = 14.08, 20.12, 22.64, 22.66, 25.46,
27.47, 29.26, 29.31, 29.32, 29.46, 29.54, 29.56, 29.58, 31.81, 31.88,
32.64, 32.71, 35.97, 46.09, 70.39, 176.34.
IR (KBr): 1731 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.86–0.90 (br m, 6 H), 1.26–1.30
(br s, 54 H), 1.57–1.65 (br m, 4 H), 2.29 (t, J = 7.5 Hz, 2 H), 4.05
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C28H56O2: C, 79.18; H, 13.29. Found: C, 79.56; H,
13.06.
13C NMR (100 MHz, CDCl3): d = 14.33, 22.92, 25.26, 26.17, 28.88,
29.39, 29.49, 29.50, 29.59, 29.71, 29.76, 29.81, 29.83, 29.88, 29.93,
32.15, 34.64, 64.61, 174.24.
Lauryl Isostearate
IR (film): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.87 (br t, 6 H), 1.26 (br s, 45 H),
1.39–1.44 (br m, 2 H), 1.56–1.64 (br m, 4 H), 2.27–2.32 (m, 1 H),
4.06 (t, J = 6.6 Hz, 2 H).
Anal. Calcd for C34H68O2: C, 80.24; H, 13.47. Found: C, 80.29; H,
13.63.
Cetyl Decanoate
13C NMR (100 MHz, CDCl3): d = 14.07, 22.63, 22.67, 26.00, 27.48,
28.72, 29.16, 29.56, 29.30, 29.35, 29.50, 29.53, 29.55, 29.57, 29.59,
29.63, 29.66, 31.80, 31.89, 31.91, 32.57, 45.86, 64.10, 176.64.
IR (KBr): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 6 H), 1.26 (br s, 38 H),
1.58–1.63 (br m, 4 H), 2.27–2.31 (t, J = 7.5 Hz, 2 H), 4.04–4.07 (t,
J = 6.7 Hz, 2 H).
Anal. Calcd for C30H60O2: C, 79.58; H, 13.36. Found: C, 79.74; H,
13.55.
13C NMR (100 MHz, CDCl3): d = 14.10, 22.66, 22.69, 25.03, 25.94,
28.65, 29.16, 29.26, 29.28, 29.37, 29.43, 29.53, 29.58, 29.65, 29.68,
29.70, 31.59, 31.87, 31.92, 34.40, 64.37, 173.98.
Myristyl Isostearate
IR (film): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.87 (br t, 6 H), 1.25 (br s, 49 H),
1.38–1.46 (br m, 2 H), 1.56–1.63 (br m, 4 H), 2.27–2.34 (m, 1 H),
4.06 (t, J = 6.6 Hz, 2 H).
Anal. Calcd for C26H52O2: C, 78.72; H, 13.21. Found: C, 78.46; H,
12.98.
Cetyl Laurate
13C NMR (100 MHz, CDCl3): d = 14.05, 14.07, 22.67, 26.00, 27.48,
28.73, 29.17, 29.26, 29.31, 29.36, 29.51, 29.53, 29.57, 29.60, 29.66,
29.68, 31.81, 31.90, 31.92, 32.57, 45.86, 64.09, 176.63.
IR (KBr): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.88 (br m, 6 H), 1.22–1.29
(br s, 42 H), 1.56–1.62 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C32H64O2: C, 79.93; H, 13.41. Found: C, 80.23; H,
13.44.
13C NMR (100 MHz, CDCl3): d = 14.32, 22.91, 25.26, 26.16, 28.88,
29.38, 29.48, 29.50, 29.58, 29.69, 29.75, 29.80, 29.83, 29.88, 29.90,
29.91, 32.13, 32.14, 34.63, 64.61, 174.23.
Cetyl Isostearate
IR (film): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.86–0.89 (br m, 9 H), 1.22–1.29
(br s, 50 H), 1.40–1.44 (br m, 2 H), 1.57–1.62 (br m, 4 H), 2.30–2.32
(br m, 1 H), 4.06 (t, J = 6.5 Hz, 1 H).
Anal. Calcd for C28H56O2: C, 79.18; H, 13.29. Found: C, 79.21; H,
13.54.
Cetyl Myristate
13C NMR (100 MHz, CDCl3): d = 14.09, 22.64, 22.68, 26.00, 27.49,
28.74, 29.17, 29.27, 29.37, 29.54, 29.58, 29.67, 29.71, 31.59, 31.82,
31.90, 31.93, 32.58, 45.88, 64.11, 176.67.
IR (KBr): 1731 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.89 (br m, 6 H), 1.23–1.27
(br s, 46 H), 1.57–1.62 (br m, 4 H), 2.28 (t, J = 7.5 Hz, 2 H), 4.04
(t, J = 6.6 Hz, 2 H).
Anal. Calcd for C34H68O2: C, 80.24; H, 13.47. Found: C, 80.14; H,
13.20.
Synthesis 2005, No. 12, 1939–1944 © Thieme Stuttgart · New York

PAPER
Esterification of Long Chain Aliphatic Carboxylic Acids
1943
Stearyl Isostearate
13C NMR (100 MHz, CDCl3): d = 14.08, 22.63, 22.67, 25.93, 27.48,
28.72, 29.17, 29.26, 29.31, 29.51, 29.53, 29.55, 29.57, 31.81, 31.89,
32.57, 45.87, 64.10, 176.66.
IR (film): 1735 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 9 H), 1.26 (br s, 54 H),
1.39–1.44 (br m, 4 H), 1.56–1.65 (br m, 4 H), 2.27–2.34 (m, 1 H),
4.04–4.08 (t, J = 6.6 Hz, 2 H).
Anal. Calcd for C28H56O2: C, 79.18; H, 13.29. Found: C, 79.35; H,
13.54.
13C NMR (100 MHz, CDCl3): d = 14.10, 22.64, 22.68, 26.00, 27.48,
28.73, 29.17, 29.27, 29.31, 29.37, 29.51, 29.54, 29.56, 29.61, 29.67,
29.71, 31.81, 31.90, 31.93, 32.58, 45.87, 64.11, 176.68.
Cetyl Oleiate
IR (film): 1740 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.87 (br t, 6 H), 1.26 (br s, 46 H),
1.58–1.63 (br m, 4 H), 1.98–2.03 (br m, 4 H), 2.28 (br t, 2 H), 4.05
(t, J = 6.7 Hz, 2 H), 5.32–5.35 (br m, 2 H).
Anal. Calcd for C36H68O2: C, 80.53; H, 13.52. Found: C, 80.61; H,
13.85.
2-Decyl Palmitate
13C NMR (100 MHz, CDCl3): d = 14.07, 22.67, 25.00, 25.93, 27.14,
27.20, 28.65, 29.09, 29.12, 29.16, 29.25, 29.31, 29.35, 29.51, 29.57,
29.65, 29.68, 29.75, 31.90, 31.91, 34.36, 64.35, 129.70, 129.94,
173.86.
IR (film): 1730 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 6 H), 1.19 (d, J = 6.6
Hz, 3 H), 1.25–1.30 (br s, 40 H), 1.44–1.49 (br m, 4 H), 1.54–1.63
(br m, 4 H), 2.24–2.31 (m, 2 H), 4.87–4.92 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 14.07, 14.09, 20.00, 22.65, 22.68,
25.11, 25.41, 29.14, 29.23, 29.29, 29.36, 29.45, 29.48, 29.50, 29.60,
29.65, 29.68, 31.85, 31.92, 34.74, 35.95, 70.66, 173.51.
Anal. Calcd for C34H66O2: C, 80.56; H, 13.12. Found: C, 80.82; H,
13.13.
Cetyl Elaidate
IR (KBr): 1735 cm–1.
Anal. Calcd for C26H52O2: C, 78.72; H, 13.21. Found: C, 79.04; H,
13.29.
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 6 H), 1.26 (br s, 46 H),
1.58–1.63 (br m, 4 H), 1.98–2.03 (br m, 4 H), 2.28 (br t, 2 H), 4.05
(t, J = 6.6 Hz, 2 H), 5.32–5.35 (br m, 2 H).
13C NMR (100 MHz, CDCl3): d = 14.09, 22.68, 25.01, 25.94, 28.66,
28.95, 29.12, 29.18, 29.25, 29.31, 29.35, 29.48, 29.52, 29.57, 29.65,
29.67, 29.69, 31.90, 31.92, 32.54, 32.60, 34.40, 64.39, 130.21,
130.45, 173.96.
2-Dodecyl Palmitate
IR (KBr): 1736 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.87–0.89 (br m, 6 H), 1.20 (d,
J = 6.3 Hz, 3 H), 1.22–1.29 (br s, 40 H), 1.45–1.65 (br m, 4 H), 2.25
(t, J = 7.4 Hz, 2 H), 4.89–4.90 (m, 1 H).
Anal. Calcd for C34H66O2: C, 80.56; H, 13.12. Found: C, 80.28; H,
13.07.
13C NMR (100 MHz, CDCl3): d = 14.07, 19.99, 22.67, 25.10, 25.41,
29.28, 29.33, 29.36, 29.45, 29.48, 29.55, 29.56, 29.60, 29.65, 29.69,
31.90, 70.65, 173.47.
Cetyl Linoleate
IR (film): 1740 cm–1.
Anal. Calcd for C28H56O2: C, 79.18; H, 13.29. Found: C, 79.46; H,
13.21.
1H NMR (400 MHz, CDCl3): d = 0.87 (br t, 6 H), 1.25 (br s, 44 H),
1.58–1.63 (br m, 4 H), 1.98–2.02 (br m, 4 H), 2.27 (br t, 2 H), 4.05
(t, J = 6.6 Hz, 2 H), 5.32–5.34 (br m, 2 H).
13C NMR (100 MHz, CDCl3): d = 14.04, 22.66, 24.98, 25.91, 27.13,
27.18, 28.65, 29.08, 29.11, 29.15, 29.24, 29.30, 29.35, 29.51, 29.56,
29.64, 29.66, 29.68, 29.74, 31.89, 31.91, 34.33, 64.30, 129.67,
129.90, 173.77.
2-Tetradecyl Palmitate
IR (KBr): 1723 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.88 (br m, 6 H), 1.17 (d,
J = 6.2 Hz, 3 H), 1.22–1.30 (br s, 44 H), 1.38–1.65 (br m, 4 H), 2.25
(t, J = 7.4 Hz, 2 H), 4.84–4.91 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 14.32, 20.23, 22.91, 25.34, 25.64,
29.38, 29.52, 29.58, 29.68, 29.71, 29.78, 29.81, 29.83, 29.88, 29.91,
32.15, 34.99, 36.18, 70.92, 173.77.
Anal. Calcd for C34H64O2: C, 80.89; H, 12.78. Found: C, 80.61; H,
13.06.
Anal. Calcd for C30H60O2: C, 79.58; H, 13.36. Found: C, 79.31; H,
13.12.
Acknowledgment
A part of this work was financially supported by a Grant-in Aid for
Scientific Research (B) 16310056, The Ministry of Education, Cul-
ture, Sports, Science and Technology. K. Mantri is grateful to the
Japan Society for the Promotion of Science (JSPS) for a postdocto-
ral fellowship.
2-Hexadecyl Palmitate
IR (KBr): 1723 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.85–0.88 (br m, 6 H), 1.18 (d,
J = 6.2 Hz, 3 H), 1.22–1.30 (br s, 48 H), 1.38–1.65 (br m, 4 H), 2.25
(t, J = 7.4 Hz, 2 H), 4.84–4.92 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 14.33, 20.24, 22.91, 25.34, 25.64,
29.38, 29.52, 29.59, 29.68, 29.71, 29.78, 29.81, 29.83, 29.88, 29.92,
32.15, 34.99, 36.18, 70.92, 173.78.
References
(1) Larock, R. C. Comprehensive Organic Transformations;
VCH: New York, 1989, 966.
(2) Otera, J. Esterification: Methods, Reactions and
Applications; Wiley-VCH: Weinheim, 2003, 303.
(3) The Chemistry of Carboxylic Acid and Esters; Patai, S., Ed.;
Wiley: New York, 1969.
Anal. Calcd for C32H64O2: C, 79.93; H, 13.41. Found: C, 79.70; H,
13.28.
2-Decyl Isostearate
IR (film): 1735 cm–1.
(4) (a) Olah, G. A.; Keumi, T.; Meidar, D. Synthesis 1978, 929.
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W. Jr. Tetrahedron Lett. 1971, 3453. (e) Nakao, R.; Oka,
1H NMR (400 MHz, CDCl3): d = 0.88 (br t, 9 H), 1.26 (br s, 40 H),
1.39–1.44 (br m, 4 H), 1.56–1.65 (br m, 4 H), 2.27–2.34 (m, 1 H),
4.04–4.08 (t, J = 6.6 Hz, 2 H).
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1944
K. Mantri et al.
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Synthesis 2005, No. 12, 1939–1944 © Thieme Stuttgart · New York