Synthesis of fluorine-containing esters of 2,5-furandicarboxylic acid

Article abstract of DOI:10.1007/s11172-018-2304-3

Fluorinated esters of 2,5-furandicarboxylic acid have been synthesized starting from 2,5-furan dicarboxylic acid dichloride and fluorine-containing diols. The reaction control was performed by means of ¹H, ¹⁹F NMR, and IR-spectroscopy. Thermal stability, as well as glass transition temperature, and intrinsic viscosity parameters of the obtained oligomers have been determined.

Full text of DOI:10.1007/s11172-018-2304-3

Russian Chemical Bulletin, International Edition, Vol. 67, No. 10, pp. 1899—1902, October, 2018
1899
Synthesis of fluorine-containing esters of 2,5-furandicarboxylic acid
A. M. Sakharov, O. U. Smirnova, A. A. Glazkov, and A. A. Yarosh
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
4
7 Leninsky prosp., 119991 Moscow, Russian Federation.
E-mail: as@zelinsky.ru, yar@ioc.ac.ru
Fluorinated esters of 2,5-furandicarboxylic acid have been synthesized starting from
,5-furandicarboxylic acid dichloride and fluorine-containing diols. The reaction control was
performed by means of H, F NMR, and IR-spectroscopy. Thermal stability, as well as glass
transition temperature, and intrinsic viscosity parameters of the obtained oligomers have been
determined.
2
1
19
Key words: 2,5-furandicarboxylic acid dichloride, polyfluorinated diols, fluorine-containing
esters of 2,5-furandicarboxylic acid, fluorine-containing oligomers, intrinsic viscosity, TGA,
DSC, NMR- and IR-spectroscopy.
The aim of this work is the development of methods
for the synthesis of new fluorinated esters using 2,5-furan-
dicarboxylic acid and polyfluorinated alcohols, including
perfluoropolyperoxide PFPP-4 obtained on an indus-
trial scale.
Synthesis of fluorine-containing esters is usually car-
ried out from anhydrides or acid chlorides of aliphatic
carboxylic acids and fluorine-containing alcohols. The
reaction is carried out under conditions of acid catalysis.
2
,3
The yield of esters reaches 73%.
These polyperoxides are formed as a result of photo-
oxidation of tetrafluoroethylene in a solution of perfluoro-
triethylamine. The general structure of polyperoxides is
Results and Discussion
CF O(CF O) A(CF CF O) COF, where A are distributed
3
2
x
2
2
y
across the macromolecule chain the units of the peroxide
2,5-Furandicarboxylic acid (FDCA) was used as an
aliphatic carboxylic acid. FDCA is the oxidation product
of 5-hydroxymethylfurfural (5-HMF), one of the main
groups (CF OOCF O), (CF CF OOCF CF O), and
2
2
2
2
2
2
(
CF OOCF CF O). The total content of active oxygen in
2 2 2
4
them ranges from 0.001 to 0.03%. Oligomers with low glass
biomaterials for chemical building blocks.
5
transition temperatures (Т ), reaching –140 °С, are ob-
We synthesized earlier fluorine-containing esters from
g
tained after the destruction of peroxide groups by various
methods and after stabilization of the resulting fluoroan-
hydride groups. Such fluids are used in aerospace engineer-
ing. A method for obtaining polyfluorinated alcohols based
on one of the representatives of polyperoxides with an
active oxygen content of 0.01% is proposed in this work.
It should be noted that when peroxides are destroyed,
a mixture of perfluorooxaalkylenecarboxylic acid mono-
and difluorides is obtained. Their composition depends
on the molecular weight of the polyperoxides, the amount
this acid and telomere-alcohol with n-2 in the presence of
various catalysts.
FDCA dichloride was synthesized by the reaction of
2,5-furandicarboxylic acid with thionyl chloride (Scheme 1).
6
Scheme 1
of active oxygen, and the ratio of the units (CF O) and
2
(
CF CF O) in the macromolecular chain.
2 2
1
We have shown earlier that application of such poly-
fluorinated alcohols in reaction with diisocyanates makes
it possible to obtain polyurethanes with Т = –136 °С.
Corresponding oligomers were obtained in ~80% yield
by reacting this dichloride with polyfluorinated alcohols
(Scheme 2). The procedure for the synthesis of polyfluor-
g
However, the method of synthesis of such polyfluorinated
alcohols has not been described in detail. We fill this gap
in this article. The oligomers synthesized on the basis of
such polyfluorinated alcohols can be used to create low-
temperature oils and lubricants.
inated alcohols is presented in the Experimental.
1
The resulting oligomer based on alcohol R with
f
1
19
M = 942 Da (according to Н and F NMR spectro-
n
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1899—1902, October, 2018.
066-5285/18/6710-1899 © 2018 Springer Science+Business Media, Inc.
1

1900 Russ. Chem. Bull., Int. Ed., Vol. 67, No. 10, October, 2018
Sakharov et al.
Scheme 2
Δm (%)
00
1
8
0
2
6
4
2
0
0
0
0
1
Rf1 = —CF(CF )OCF CF(CF )OCF (CF ) CF OCF(CF )CF OCF-
3
2
3
2
2 4
2
3
2
(
CF )—
3
3
200
400
T/°C
Rf2 = CF O(CF O) (CF CF O) CF — and —CF O(CF O)28-
2
28
2
2
7
3
2
2
(
CF CF O) CF (20 : 80 mol.%)
Fig. 3. TGA curve of oligomer based on FDCA dichloride and
2
2
7
2
2
diol-2 (R ) under air (1) and under argon atmosphere (2).
f
scopy) had an intrinsic viscosity [η] = 0.09 dL g–1 (solu-
tion in C F ). Data of TGA (under argon and under air)
6
6
and DSC for oligomer based on FDCA dichloride and diol
exo
1
Rf are presented in Figs 1 and 2, respectively.
0
.2 W g–1
The temperature of the onset of decomposition of this
oligomer is 250 °С (see Fig. 1), and T ≈ −27 °С (see Fig. 2).
g
Data of TGA (under argon and under air) and DSC
2
for oligomer based on FDCA dichloride and diol-2 (R )
f
1
19
with M = 2442 Da (according to Н and F NMR spec-
n
troscopy) are presented in Figs 3 and 4, respectively.
It follows from the above data that the temperature at
which the oligomer starts to decompose is 200 °С (see Fig. 3),
−
120
−80
−40
0
40
80 T/°C
Fig. 4. DSC thermogram for oligomer based on FDCA dichloride
and diol-2 (R ) (T ≈ –135 °С).
2
f
g
Δm (%)
1
00
and T ≈ −135 °С (see Fig. 4). The resulting oligomer based
g
2
–1
on alcohol with Rf has [η] = 0.10 dL g (solution
8
0
0
0
0
0
1
in C F ).
6
6
Thus, we have obtained new polyfluorinated esters
based on 2,5-furandicarboxylic acid dichloride and poly-
fluorinated diols. Some characteristics of the obtained
oligomers, namely, the temperature of the onset of de-
composition under argon and under air, the glass transition
6
4
2
2
temperature, the intrinsic viscosity of the solution in C F ,
6
6
the NMR and IR spectra of the synthesized oligomers
were determined.
2
00
400
T/°C
Fig. 1. TGA curve of oligomer based on FDCA dichloride and
Experimental
1
diol-1 (R ) under air (1) and under argon atmosphere (2).
f
1H and 19F NMR spectra were registered using a Bruker
3
2
00SF spectrometer (300.13 MHz (external standard ТМS) and
82.40 MHz (external standard CFCl ), respectively. FTIR
exo
3
.1 W g–1
spectra were obtained using a Bruker Alpha-T spectrometer.
Differential scanning calorimetry (DSC) measurements were
carried out using a DSC-822e scanning calorimeter (Mettler-
0
–
1
Тоledo, Switzerland) at heating rate of 10 °C min with the
samples of ~10 mg weight. Thermogravimetric investigation were
carried out using Derivatograth-C (МОМ, Hungary) under air
−
80 −40
0
40
80
120
160 T/°C
–
1
Fig. 2. DSC thermogram for oligomer based on FDCA dichloride
and argon atmosphere at heating rate of 10 °C min with the
1
and diol-1 R .
samples of ~20 mg weight.
f

F-containing esters of 2,5-furandicarboxylic acid
Russ. Chem. Bull., Int. Ed., Vol. 67, No. 10, October, 2018
1901
Synthesis of 2,5-furandicarboxylic acid dichloride. Thionyl
chloride (10 mL, 138 mmol), 2,5-dicarboxylic acid (5 g, 32 mmol),
and DMF (0.08 mL, 1 mmol) were loaded into a two-neck flask
with a capacity of 50 mL, equipped with a magnetic stirrer, reflux
condenser, and trap with an aqueous solution of KOH. The flask
was heated in an oil bath (up to 70 °С) until the release HCl and
fluorine compounds). The autoclave was discharged, the mixture
was filtered from the catalyst on a Buchner funnel under inert at-
mosphere. The yield of a mixture of mono- and difluoroanhy-
drides of perfluorooxaalkylenecarboxylic acids was 600—650 g
(60—65%). The resulting product did not contain peroxide
groups, determined using iodometric analysis. A part of these
fluoroanhydrides contained unstable fluoroformate groups.
B. Stabilization of fluoroanhydrides. A four-necked flask with
a capacity of 0.5 L, equipped with a stirrer with mercury-free
adapter, a reflux condenser, an addition funnel with a venting
tube, and an inert gas supply tube, was purged with dry argon for
30 min. Then, dry CsF (2 g), dry diglyme (20 mL) were loaded
into the flask. A mixture of fluoroanhydrides (600 g) was gradu-
ally introduced with vigorous stirring and at 20 °С. At the same
time, a rapid release of carbonyl fluoride was observed. The reac-
tion mass was stirred for 1 h, warmed to 60 °С, and the fluorine-
carbon layer was separated. A mixture of fluoroanhydrides (530 g,
SO ceased. The mixture was evacuated, the product was subli-
2
mated. White crystalline compound with m.p. = 78 °С was ob-
tained. Found (%): С, 37.37; 37.35; H, 0.92; 0.94; Cl, 36.75;
3
6.92. C H Cl O . Calculated (%): C, 37.3; H, 1.0; Cl, 36.8. IR,
6 2 2 3
–
1
ν/cm : 3144 and 1201 (СН of furan nucleus), 1746 (С=О
1
in dichloroanhydride). Н NMR (CDCl ), δ: 7.60 (s, 2 Н from
furan nucleus).
3
1
Synthesis of polyfluorinated alcoholes (R ) from dimethyl
f
ethers of polyfluorooxaalkylenedicarboxylic acids. Polyfluorinated
diols were obtained by the reduction of the corresponding di-
methyl ethers of perfluorooxaalkylenedicarboxylic acids in the
19
presence of NaBH according to a previously published proce-
yield 88%) was obtained. According to F NMR data the signal
4
7
dure. (Scheme 3).
at δ +15, characteristics of fluorine in fluoroformate group
1
9
19
F NMR (CFCl CF Cl), δ: −82.72 and −85.10 (both m,
(OCOF), was absent in fluoroanhydrides. F NMR, δ: 10
2
2
1
2 F from CF3 and 8 F from CF O); −124.30 (m, 4 F from
(s, (С(О)F); −(50—55) (ds, CF O); −58.0 (s, CF O); −81.5
2
2 3
CF CF CF CF ), –125.55 (m, 4 F from CF CF CF CF );
(s, ОCF C(O)F);–(85—90) (ds, CF CF O). From the ratio of
2 2 2
2
2
2
2
2
2
2
2
−
138.94 (m, 2 F from OCF(CF )CH OH); −147.21 (m, 2 F from
the integral intensities of all these signals, one can determine the
molar ratio of the indicated groups and Mn of the obtained
products. The Mn value of the fluoroanhydride mixture was
3
2
1
OCF(CF )CF ). H NMR (CFCl CF Cl), δ: 4.84 (s, 2 HO); 4.0
3
2
2
2
–
1
and 3.97 (both t, 4 H from CH OH). IR, ν/cm : 1134—1114
2
–
1
19
–1
(
CF ). The absorption band at 1780 см (C=O of ester) is absent.
2450 Da according to F NMR. The band at 1880 cm , cor-
responding to С=О in perfluorocarbonic acid fluoride, is present
in IR spectrum.
2
2
Synthesis of polyfluorinated alcoholes (R ) from perfluo-
f
ropolyperoxides PFPP-4.
2
А. Hydrogenation of perfluoropolyperoxides PFPP-4. Per-
fluoropolyperoxides (PFPP-4, GosNIIOKhT) are the products
of photochemical oxidation of tetrafluoroethylene. They were
used as 50—60% solutions in perfluorotriethyl amine (solvent
MD-3F). The solvent was removed on a rotary evaporator under
reduced pressure before hydrogenation. A clear, colorless liquid
C. Synthesis of ethyl esters (R ) of perfluorooxaalkylenedi-
f
carboxylic acids. A mixture of mono- and difluoroanhydrides
(200 g) was charged into a 0.5 L flask equipped with a stirrer,
a reflux condenser, and an addition funnel. An absolute ethanol
(20 mL) was added dropwise at ~20 °С under vigorous stirring.
Then the reaction mass was heated to 60 °С and stirred for 1 h.
The mixture of the esters was washed twice with ice water, dried
with a kinematic viscosity of 300—500 cSt (20 °С) and Mn
=
=
15000—20000 Da (ebullioscopy in C F ) was obtained. The
with CaCl and filtered. A mixture of ethyl esters (198 g, yield
6
6
2
–
1
content of active oxygen after removal of the solvent ranged from
98%) was obtained. The bands at 1780 cm (С=О in ester) and
–
1
0
.6 to 1.0%.
at 2800—2930 cm (СН) are present in the IR spectrum of the
–
1
Perfluoropolyperoxide (1 kg) was charged into a 1 L autoclave
reaction products, the band at 1880 cm is absent.
1
lined with polytetrafluoroethylene. A dry catalyst (50 g), acti-
vated carbon containing 2% palladium, was added. The autoclave
was purged with hydrogen. Hydrogenation was carried out at
D. Synthesis of fluoroorganic alcohols (R ) from ethyl esters
f
of perfluorooxaalkylenedicarboxylic acids. Absolute EtOH (75 mL),
NaBH (3.63 g, 101 mmol) were placed into a flask equipped
4
6
0 °С and a hydrogen pressure of 10 MPa for 6 h. The rota-
with a stirrer, a reflux condenser, and an addition funnel.
Perfluoroxaalkylenecarboxylic acid ethyl esters (50 g, 32 mmol)
were slowly added dropwise under vigorous stirring and cooling
(−20 °С). The mixture was stirred at this temperature for 2.5 h.
tion speed of the autoclave was 50 rpm. Then, the autoclave was
cooled to ~20 °С, gently discharged from it gaseous prod-
ucts (hydrogen, hydrogen fluoride, carbonyl fluoride, and ot ano-
Scheme 3

1902 Russ. Chem. Bull., Int. Ed., Vol. 67, No. 10, October, 2018
Sakharov et al.
Then the temperature of the reaction mass was adjusted to 70 °С
and kept for another 3 h. Then the reaction mixture was cooled
to 20 °С and 2 N HCl solution (50 mL) was added. Hydrolysis
was carried out at 40 °С for 2 h. Chladon-113 (50 mL) was
−147.21 (m, 2 F from OCF(CF )CF ). TGA and DSC data for
3 2
oligomer are represented in Figs 1 and 2, T ≈ −27 °С.
g
An oligomer based on FDCA dichloride and diol-2 was
obtained in a similar way. TGA and DSC data for oligomer are
added to the flask, the organfluoric layer was washed with Н О
represented in Figs 3 and 4, T ≈ −135 °С.
2
g
(
4×50 mL), dried over MgSO , and filtered. Chladon-113 was
4
distilled off at a high-vacuum installation. The target product
The authors are grateful to M. I. Buzin and G. G.
Nikiforova of A. N. Nesmeyanov Institute of Organoelement
Compounds of the Russian Academy of Sciences for car-
rying out polymer examination by DSC and TGA.
19
(
(
(
40 g, yield 70%) was obtained. F NMR (C F ), δ: −50.5
6 6
s, 3 F from CF O); −52.2 and −53.9 (both m, OCF O); –86.1
3
2
t, 2 F from OCF CH OH); −87.4 and –89.19 (both m,
2
2
1
OCF CF O). H NMR (C F ), δ: 5.1 (s, 2 H, HO); 3.6—3.7
2
2
6 6
–
1
(
(
t, 4 H from CF CH OH, J = 9.5 Hz). IR, ν/cm : 1114—1134
2 2
–
1
References
CF ); 3450 (br., ОН). The band at 1780 cm (С=O of ester) is
2
1
19
absent. According to H and F NMR spectroscopy the obtained
2
alcohols are mixture of mono and diols (diol-2, R ): CF OCF O-
1. O. Smirnova, A. Glazkov, A. Yarosh, A. Sakharov, Molecules,
2016, 21, 904.
2. R. Filler, J. V. Fenner, C. S.Stokers, J. F. O´Brien, M. Haup-
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113, 1499.
5. А. М. Sakharov, O. U. Smirnova, A. А. Yarosh, Fluorine
Notes, 2017, 113, 7.
f
3
2
(
(
CF O) (CF CF O) CF CH OH and HOCH CF O(CF O) -
2 28 2 2 7 2 2 2 2 2 28
CF CF O) CF CH OH in ratio 20 : 80 (%) respectively, for
2
2
7
2
2
diol-2 M = 2442 Da.
n
Synthesis of oligomers and polymers from fluorine-containing
diols and 2,5-furandicarboxylic acid dichloride was carried out
7
similarly to published early procedure, but triethylamine was
used as a catalyst.
1
The FDCA dichloride (0.63 g, 2 mmol), diol-1 (R ) (3 g,
f
2
mmol), and TEA (0.5 mL) were loaded into a two-necked flask
with a capacity of 50 mL, equipped with a magnetic stirrer,
a reflux condenser, and a trap with an aqueous 5% KOH solution.
The mixture was heated to 70 °С for 2.5 h, dissolved in C F ,
6. J. C. Morales-Huera, A. M. DeIlarduya, S. Munoz-Guerra,
Polymer, 2016, 87, 148.
7. E. N. Ushakova, O. V. Konyushko, A. A. Glazkov, S. P.
Krukovsky, Russ. Chem. Bull., 1996, 45, 1501.
6
6
filtered, and evaporated under reduced pressure. Viscous liquid
–
1
with [η] = 0.09 dL g (solution in C F ) was obtained. IR,
6
6
–
1
ν/cm : 3433 (CН of furan nucleus); 1780 (С=O of ester);
1
1
134—1114 (CF ). Н NMR (C F ), δ: 7.3 (s, 2 Н from fu-
2
6 6
19
ran nucleus); 4.9 (t, 4 Н from OCH CF ). F NMR (C F ), δ:
2
2
6 6
−
−
82.72 and −85.10 (both m, 12 F from CF and 8 F from CF O);
Received April 25, 2018;
in revised form June 8, 2018;
accepted August 10, 2018
3
2
124.30 (m, 4 F from CF CF CF CF ); −125.55 (m, 4 F from
2
2
2
2
CF CF CF CF ); −138.94 (m, 2 F from OCF(CF )CH OH);
2
2
2
2
3
2