Green Process for 5-(Chloromethyl)furfural Production from Biomass in Three-Constituent Deep Eutectic Solvent

Article abstract of DOI:10.1002/cssc.202002631

5-(Chloromethyl)furfural (CMF), a versatile bio-platform molecule, was first synthesized in a three-constituent deep eutectic solvent (3c-DES) including choline chloride, AlCl₃ ? 6H₂O, and oxalic acid. In particular, 3c-DES was conducive for the production of CMF from glucose and provided a CMF yield of 70 % at 120 °C within 30 min. In addition, CMF yields reached up to 86, 80, 30, 29, and 35 % from fructose, sucrose, cellulose, bamboo, and bamboo pulp, respectively. This study opens new avenues for the preparation of CMF.

Full text of DOI:10.1002/cssc.202002631

Chemistry–Sustainability–Energy–Materials
Accepted Article
Title: Green process for 5-(chloromethyl)furfural production from
biomass in three-constituent deep eutectic solvent
Authors: Binglin Chen, Zheng Li, Yunchao Feng, Weiwei Hao, Yong
Sun, Xing Tang, Xianhai Zeng, and Lu Lin
This manuscript has been accepted after peer review and appears as an
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To be cited as: ChemSusChem 10.1002/cssc.202002631
Link to VoR: https://doi.org/10.1002/cssc.202002631
01/2020

10.1002/cssc.202002631
ChemSusChem
COMMUNICATION
Green process for 5-(chloromethyl)furfural production
from biomass in three-constituent deep eutectic
solvent
Binglin Chen†,[a] Zheng Li†,[b] Yunchao Feng,[a] Weiwei Hao,[a] Yong Sun,[a,c,d] Xing
Tang,[a,c,d] Xianhai Zeng*,[a,c,d] Lu Lin[a,c,d]
[a]
B. L. Chen, Y. C. Feng, W. W. Hao, A/Prof. Y. Sun, A/Prof. X. Tang, Prof. X. Zeng, Prof. L. Lin
College of Energy, Xiamen University
Xiamen 361102 (P.R. China)
E-mail: xianhai.zeng@xmu.edu.cn
[b]
[c]
[d]
[†]
Dr. Z. Li
Department of Biological Systems Engineering, University of Wisconsin
Madison 53719 (US)
A/Prof. Y. Sun, A/Prof. X. Tang, Prof. X. H. Zeng, Prof. L. Lin
Fujian Engineering and Research Centre of Clean and High-valued Technologies for Biomass
Xiamen 361102 (P.R. China)
A/Prof. Y. Sun, A/Prof. X. Tang, Prof. X. H. Zeng, Prof. L. Lin
Xiamen Key Laboratory of Clean and High-valued Utilization for Biomass
Xiamen 361102 (P.R. China)
These authors contributed equally to this work.
Supporting information for this article is given via a link at the end of the document.
Abstract: 5-(Chloromethyl)furfural (CMF), a versatile bio-platform
molecule, was first synthesized in a three-constituent deep eutectic
solvent (3c-DES) including choline chloride, AlCl3·6H2O, and oxalic
acid. In particular, 3c-DES was conducive for the production of CMF
from glucose and provided a CMF yield of 70% at 120 ℃ within 30
min. In addition, CMF yields reached up to 86, 80, 30, 29, and 35%
from fructose, sucrose, cellulose, bamboo, and bamboo pulp,
respectively. This study opens new avenues for the preparation of
CMF.
with a yield of 45% [10]. However, it did not receive enough
attention until CMF was efficiently prepared directly from glucose
[5]
and cellulose with HCl/dichloroethane (DCE) system in 2008
,
which broadens the road of CMF synthesis. Inspired by this work,
various processes have been developed based on the typical
HCl/DCE system, such as intermittent extraction[11], microwave
heating[12], and using benzyltributylammonium chloride (BTBAC)
as phase transfer catalyst [13]. Much effort has been devoted to
the field of CMF production, but some inevitable shortcomings,
such as highly corrosive concentrated acid, harsh conditions,
and long reaction time should not be ignored. Thus, developing a
green, safe, and high-efficient process to produce CMF from
renewable biomass besides sugar is desirable.
Considering the depletion of fossil resources, it is urgent to
develop biomass utilization for preparation of the alternative
renewable chemicals[1]. To date, 5-hydroxymethylfurfural (HMF)
has been in the spotlight as an intermediate for the valorization of
biomass into value-added chemicals, biofuels, and functional
materials[2]. However, the inevitable condensation reaction and
humins formation under acidic conditions make the separation
and purification of HMF enormously challenging [3]. Hence, it
limits large-scale industrial applications of HMF as a bio-based
platform chemical.
Recently, 5-(chloromethyl)furfural (CMF), as a key platform
molecule, has attracted much attention for the preparation of
monomers, biofuels, and versatile chemicals (Figure 1) such as
[4]
[5]
2,5-furandicarboxylate
,
alkoxymethylfurfurals
,
[6]
δ-aminolevulinic acid (ALA)
,
and gasoline-like C8-C10
hydrocarbons [7]. Compared with HMF, CMF is more stable and
has excellent hydrophobicity, which markedly facilitate the
isolation and purification processes [8]. Moreover, the most
remarkable feature of CMF is that it could be obtained with higher
yield directly from biomass[5].
Figure 1. 5-(Chloromethyl)furfural (CMF) as a bio-platform molecule.
In our previous work[14], a novel method for the synthesis of
CMF based on deep eutectic solvent (DES) consisting choline
chloride (ChCl) and sugars was developed. The dependence on
concentrated HCl was eliminated, and CMF could be prepared
with 50 and 17% yield from fructose and glucose, respectively
In early 1901, the synthesis of CMF was first realized via the
reaction of carbohydrates and hydrochloric acid (HCl) [9]. In 1981,
CMF was obtained from glucose with HCl/chlorobenzene system
1
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10.1002/cssc.202002631
ChemSusChem
COMMUNICATION
(Table 1, entry 5). In this work, we followed up on the DES-based
synthesis of CMF with a three-constituent DES (3c-DES)
including ChCl, AlCl3·6H2O, and oxalic acid (OA). A CMF yield up
to 70% from glucose was obtained at 120 ℃ within 30 min
(Table 1, entry 6), and the CMF yield could be further improved
to 76% by intermittent extraction (Table 1, entry 7). Compared to
previous reports, 3c-DES provided not only milder conditions, but
also competitive yields within much shorter reaction time for the
synthesis of CMF.
Figure 2d showed the effect of AlCl3·6H2O loading on product
distribution. A CMF yield of 25% and almost 0% HMF were
obtained in the controlled experiment without AlCl3·6H2O. When
0.5 mmol of AlCl3·6H2O was introduced into the reaction system,
the CMF yield was dramatically increased to 42%. Further
increasing AlCl3·6H2O loading to 2 mmol led to a 52% CMF yield.
However, when 3.5 mmol of AlCl3·6H2O was applied, the yield of
CMF decreased to 42%. This was caused by the formation of
by-products (e.g., humins) due to overmuch acid sites in the
system[15a, 17]. It is also noteworthy that AlCl3·6H2O loading up to
3.5 mmol led to nearly complete glucose conversion.
Table 1. Comparison between reported methods for the synthesis of CMF from
glucose.
Entry
Catalytic system
Reaction
conditions
Yield
(%)
Ref.
1
2
HCl
HCl
75±2 ℃, 24 h
45
81
[10]
[11]
100 ℃, 1 h, 3
times
80 ℃, 0.25 h,
microwave
3
HCl
39
64
17
70
[12]
4
HCl, BTBAC
ChCl, AlCl3·6H2O
90 ℃, 3 h
[13]
5
120 ℃, 5 h
120 ℃, 0.5 h
[14]
6[a]
ChCl, AlCl3·6H2O,
oxalic acid
This work
7[b]
ChCl, AlCl3·6H2O,
oxalic acid
120 ℃, 0.5 h, 3
times
76
This work
Reaction conditions for this work: 0.4 mmol glucose,12.5 mmol ChCl, 15 mmol
oxalic acid, 2 mmol AlCl3·6H2O. [a] 15 mL DCE. [b] extracted with 15 mL DCE
every 0.5 h, 3 times.
Various organic carboxylic acids have been screened in the
3c-DES/DCE system (Figure 2a). In a controlled reaction without
carboxylic acid additives, CMF (17%) and HMF (2%) were
detected as major products. When oxalic acid (OA) was
introduced into the reaction, the yield of CMF increased to 46%,
followed by malic acid (MA, 30%), citric acid (CA, 27%), formic
acid (FA, 25%), succinic acid (SA, 20%), and acetic acid (HAc,
17%). After reaction, the color of the biphasic reaction system
darkened due to the formation of humus in the process[15], which
was the reason that oxalic acid, as a part of 3c-DES, provided
complete glucose conversion but only a moderate CMF yield
(46%) (Figure S1). The effect of oxalic acid loading on the
product was also explored, as shown in Figure 2b. The optimal
loading of oxalic acid was 15 mmol, providing a 51% CMF yield.
The introduction of oxalic acid obviously enhanced the catalytic
performance of DES since both carboxylic groups and the
possible chelation between oxalic acid and Al contribute to the
strong Brønsted acidity [16], which promoted sugars dehydration
and also HMF chlorination by in situ formation of hydrochloric
acid.
Figure 2. (a) Glucose conversion, CMF and HMF yields obtained in the
presence of various organic acids. (b) Effects of oxalic acid loading. (c) Effects
of various metal salts. (d) Effects of different loading of AlCl3·6H2O. (e) CMF
production from glucose in 3c-DES/DCE media. Reaction conditions: 2 mmol
glucose, 12.5 mmol ChCl, 15 mL DCE, 120 ℃, 2 h. (a) 12.5 mmol organic
acids and 2.5 mmol AlCl3·6H2O; (b) 2.5 mmol AlCl3·6H2O; (c) 15 mmol OA and
2.5 mmol metal salts; (d) 15 mmol OA.
Figure 2e showed the biphasic system for CMF production
from glucose including 3c-DES phase (bottom) and organic
extraction phase (DCE, top). In 3c-DES phase, glucose was
dehydrated to HMF and then halogenated to CMF. CMF was
further extracted into the organic phase, which effectively
inhibited proton-induced degradation to HMF, LA and further
Figure 2c showed the effect of various metal salts on CMF
preparation. It was noted that AlCl3·6H2O provided the highest
CMF yield (51%), which was followed by CrCl3·6H2O (50%) and
MgCl·6H2O (48%). In addition, the resulting 3c-DES including
AlCl3·6H2O, CaCl2·2H2O, MgCl2, or AlCl3 were liquid at room
temperature, which all showed excellent “deep” and “eutectic”
characters (Figure S2). In view of catalytic activity, safety, and
accessibility, we selected AlCl3·6H2O for further experiments.
condensation to humins [18]
.
It was also noticed that the synthesis of CMF in 3c-DES was
greatly affected by extraction agents. As shown in Table S1,
2
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10.1002/cssc.202002631
ChemSusChem
COMMUNICATION
several industrial available aprotic solvents have been screened.
Chlorinated solvents such as DCE, dichloromethane, and
trichloroethane exhibited the stronger extraction ability, and the
maximum CMF yield was 52, 51, and 50% at 120 ℃ in 2 h,
respectively. Given the good performance, low reaction pressure,
accessibility and fair price (about $400 per ton), DCE was
elected as the optimal extracting agent for 3c-DES based CMF
production.
should be mostly provided by ChCl. To prove this hypothesis,
different aluminum salts and choline bromide (ChBr) were used
instead of AlCl3·6H2O and ChCl. When AlCl3·6H2O was replaced
with Al2(SO4)3·18H2O, the yield of CMF decreased slightly (Table
S2, entry 2), indicating that the Cl- provided by AlCl3·6H2O was
not the major source of the Cl in CMF. Replacing AlCl3·6H2O with
AlBr3 gave
a
CMF yield of 62% along with 6% of
5-(bromomethyl)furfural (BMF) (Table S2, entry 3), which also
suggested that the halogen in aluminum salt contributed to only a
small part of halogenation of HMF. Furthermore, using
ChBr/Al2(SO4)3·18H2O/oxalic acid together led to a BMF yield of
67% (Table S2, entry 4). These results clearly proved that the
halogen atoms in CMF or BMF were mainly supplied by ChCl or
ChBr.
The effects of DCE volume were also studied (Table S1, entry
16-23). When the experiment was carried out without any
extracting agent, the system was severely coked and almost no
target products were detected. When the DCE volume was
increased to 15 mL, the CMF yield increased significantly to 52%.
Further increasing DCE volume did not greatly affect the yield of
CMF. In order to improve the sustainability of extractant, the
recyclability of DCE was studied (Figure S3). After evaporation,
DCE (> 95% purity) was obtained and reused for five more runs,
and the yield of CMF was almost unchanged.
Scheme 1. Plausible mechanism for the production of CMF from glucose in
3c-DES.
Figure 3. Effects of reaction time and temperature on (a) CMF yield and (b)
HMF yield. Reaction conditions: 2 mmol glucose, 12.5 mmol ChCl, 15 mmol
OA, 2 mmol AlCl3·6H2O, 15 mL DCE.
Figure 3 shows the effects of reaction time and temperature on
the yields of CMF and HMF. The reaction reached equilibrium
state faster at higher reaction temperature, and the maximum
CMF yield (55%) was obtained after 30 min at 120 °C. However,
the DES system was likely to be destroyed at 130 °C and the
yield of CMF was lower [19]. On the contrary, HMF yield
decreased as the reaction proceeded (Figure 3b), which proved
that glucose was first dehydrated to form HMF in 3c-DES, and
HMF was further halogenated to CMF in the presence of protons
and abundant Cl-. Note that hydrogen bond could also be formed
between HMF and ChCl (Scheme 1), which increased the
stability of HMF and reduced the occurrence of side reactions
(e.g., the formation of humins) [20]. Meanwhile, the maximum of
HMF was only 6% at 130 °C in 10 min, indicating that
halogenation of HMF to CMF is the fast step in this system.
Figure 4. Catalytic behavior of 3c-DES system for the transformation of
glucose to CMF over 10 consecutive cycles. Reaction conditions: 0.4 mmol
glucose, 12.5 mmol ChCl, 15 mmol OA, 2 mmol AlCl3·6H2O, 120 ℃, 0.5 h, 15
mL DCE.
The reusability of 3c-DES is a key factor for the scale-up
production of CMF. It was verified that after the reaction was
completed, the aftertreatments of the remaining 3c-DES mixture
was not required prior to the next run with new starting materials
and (recycled) DCE. As shown in Figure 4, a CMF yield of 64%
could still be achieved after 7 cycles with a glucose loading of 0.4
mmol. However, only 24% CMF yield and 19% HMF were
obtained in the 10th cycle, probably because that the proton, Cl-
in the system was depleted and the system was contaminated by
various byproducts, thus it could not keep the reaction going
normally. Fortunarely, CMF yield could be improved back to 70%
if equimolar of ChCl and oxalic acid were added to the reaction
Based on the discussion above, a plausible mechanism for
CMF production from glucose in 3c-DES was proposed, as
shown in Scheme 1. First, glucose was converted into enediolate
intermediate in 3c-DES [2a, 21]. Under the action of Lewis acid
(Al3+), fructose formed by isomerization and then dehydrated to
HMF (path A) [22]. On the other hand, enediolate intermediate
could be directly dehydrated into HMF catalyzed by Brønsted
acid (path B) [21]. The sources of Cl in CMF were also further
verified. During the halogenation process, the halogenation of
HMF was relied on the in-situ generated “hydrochloric acid”,
which was composed of the proton ionized from oxalic acid and
abundant Cl- provided by ChCl and AlCl3·6H2O. Considering that
the amount of ChCl was higher than AlCl3·6H2O, the Cl- in CMF
3
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10.1002/cssc.202002631
ChemSusChem
COMMUNICATION
system (after 10 cycles). Meanwhile, it also indicated that the Cl
in CMF preparation was mainly provided by ChCl.
catalytic reactivity for glucose; 4) excellent reusability and water
resistance. For commercial perspectives, ChCl as animal feed
additive and plant photosynthesis promoter, oxalic acid as a
natural product of plants, and AlCl3·6H2O as common salts are
all commercially available and inexpensive. Moreover, this work
also sheds some light on the study of multicomponent DES for
the valorization of biomass.
Table 2. Effects of substrate, substrate loading and water on CMF production.
Entry
Substrate
0.4 mmol substrate
loading
2 mmol substrate
loading
CMF(%)
70
HMF(%)
<1
CMF(%)
55
HMF(%)
Experimental Section
1
2
3
4
5
6
7
8
9
10
Glucose
<1
<2
<2
<1
<1
<1
<1
<1
<1
<1
Fructose
86
<1
78
Materials
CMF (95%) was produced according to the literature [5]. HMF
(99%) was purchased from Sigma-Aldrich Co. Ltd. (USA), and
other analytical reagents and chemicals were purchased from
Sinopharm Chemical reagent Co. Ltd. (Shanghai, China).
Sucrose[a]
Cellulose[a]
Bamboo[a]
Bamboo pulp[a]
Glucose[b]
Glucose[c]
Glucose[d]
Glucose[e]
80
<1
68
30
<1
17
29
<1
15
Preparation and recycle of DES
35
<1
22
Each DES component was weighed and added to
a
70
<1
55
round-bottom flask. The mixture was heated at 100 °C with
stirring until a complete liquid phase was formed. After the
reaction was completed, the organic phase was separated, and
the residual DES was reused without any treatment. The new
glucose and DCE were added into the reactor for the next cycle.
69
<1
55
63
<1
51
76
<1
60
Typical process for the CMF production
Reaction conditions: 12.5 mmol ChCl, 15 mmol OA, 2 mmol AlCl3·6H2O,
120 ℃, 0.5 h, 15 mL DCE. [a] Based on the hexose content of analyzed
biomass substrates. [b] 5 wt%, [c] 10 wt%, and [d] 20 wt% water was added
into reaction (based on DES weight). [e] extracted with 15 mL DCE every 30
min, 3 times.
In a typical procedure, the CMF production reacted in a 120 mL
glass bottle equipped with a Teflon screw top (Beijing Synthware
Glass). 2 (or 0.4) mmol substrate (based on the hexose content
of analyzed biomass substrates) was introduced into DES, and
15 mL organic solvent was added in the reactor. The solution
was then stirred at 120ꢀ°C. After reaction, the reactor was cooled
to room temperature. The DCE phase was separated and the
DES phase was extracted with 15 mL additional extraction
solvent for two more times. The organic phase containing CMF
and HMF was analyzed by GC-MS, while the solid phase was
dissolved with deionized water and analyzed by HPLC to
determine the amount of unreacted bio-based sugar.
Encouraged by the promising results obtained using 3c-DES,
we then broadened the scope of substrate for CMF production
using the same reaction conditions. Various biomass substrates
with different loadings were tested for CMF production in
3c-DES/DCE system (Table 2), and the yields of CMF were 86,
80, 70, 30, and 29% from 0.4 mmol of fructose, sucrose, glucose,
cellulose and bamboo as substrates, respectively (entry 1-5).
When the substrate loading was increased to 2 mmol, CMF
yields of 78 and 68% were obtained from fructose and sucrose,
respectively. While untreated raw bamboo only provided 29%
Acknowledgements
CMF yield, bamboo pulp prepared by the previously reported
[23]
CAOSA method
provided 35% CMF yield (entry 6), which
might be ascribed to that the crystallinity of cellulose in
pretreated bamboo pulp was much lower than that of natural
bamboo [12, 24], therefore the hydrolysis of cellulose to glucose
was easier. Moreover, the effect of water was also explored.
When 5~20 wt% water was added into the reaction medium, the
yields of CMF were no less than 63% (entry 7-9), suggesting that
the 3c-DES reaction system had good water resistance against
This work was financially supported by the National Natural
Science Foundation of China (No. 21978248), and the Natural
Science
Foundation
of
Fujian
Province
of
China
(No.2019J06005).
Keywords: 5-(chloromethyl)furfural (CMF) • carbohydrates •
biomass • deep eutectic solvent
external or in-situ generated moisture, which provided
a
promising application prospect of large-scale production of CMF.
Intermittent extraction further increased the yield of CMF to 76%
after extracting the 3c-DES phase with fresh DCE every 30 min
for 3 times (entry 10).
[1]
a) Y. Liao, S.-F. Koelewijn, G. Van den Bossche, J. Van
Aelst, S. Van den Bosch, T. Renders, K. Navare, T. Nicolaï,
K. Van Aelst, M. Maesen, Science 2020, 367, 1385-1390;
b) C. Xu, E. Paone, D. Rodríguez-Padrón, R. Luque, F.
Mauriello, Chem. Soc. Rev. 2020, 49, 4273-4306; c) T. A.
Bender, J. A. Dabrowski, M. R. Gagné, Nat. Rev. Chem.
2018, 2, 35-46.
a) H. Zhao, J. E. Holladay, H. Brown, Z. C. Zhang, Science
2007, 316, 1597-1600; b) J. Z. Chen, R. L. Liu, Y. Y. Guo,
L. M. Chen, H. Gao, ACS Catal. 2015, 5, 722-733; c) Y.
Feng, G. Yan, T. Wang, W. Jia, X. Zeng, J. Sperry, Y. Sun,
In conclusion, a novel and specially designed 3c-DES was
employed for CMF production, which exhibited several promising
features including 1) eliminating the reliance on concentrated
hydrochloric acid; 2) moderate reaction conditions; 3) high
[2]
4
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10.1002/cssc.202002631
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COMMUNICATION
X. Tang, T. Lei, L. Lin, Green Chem. 2019, 21, 4319-4323;
Technol. 2019, 195, 106159; c) I. Bodachivskyi, U.
Kuzhiumparambil, D. B. G. Williams, ChemSusChem 2019,
12, 3263-3270; d) W. M. Lawton, J. Mol. Catal. A: Chem.
2010.
a) Y. Feng, Z. Li, S. Long, Y. Sun, X. Tang, X. Zeng, L. Lin,
Green Chem. 2020, 22, 5984-5988; b) B. Chen, G. Xu, Z.
Zheng, D. Wang, C. Zou, C. Chang, Ind. Crops Prod. 2019,
129, 503-511.
a) Y. Feng, M. Li, Z. Gao, X. Zhang, X. Zeng, Y. Sun, X.
Tang, T. Lei, L. Lin, ChemSusChem 2019, 12, 495-502; b)
V. Choudhary, S. H. Mushrif, C. Ho, A. Anderko, D. G.
Vlachos, J. Am. Chem. Soc. 2013, 135, 3997–4006.
Y. Liu, W. Chen, Q. Xia, B. Guo, Q. Wang, S. Liu, Y. Liu, J.
Li, H. Yu, ChemSusChem 2017, 10, 1692-1700.
a) M. Zuo, K. Le, Z. Li, Y. Jiang, X. Zeng, X. Tang, Y. Sun,
L. Lin, Ind. Crops Prod. 2017, 99, 1-6; b) Y. Feng, G. Yan,
T. Wang, W. Jia, X. Zeng, J. Sperry, Y. Sun, X. Tang, T.
Lei, L. Lin, ChemSusChem 2019, 12, 978-982.
L. Hu, Y. Sun, L. Lin, S. Liu, Biomass Bioenergy 2012, 47,
289-294.
d) Y. Feng, W. Jia, G. Yan, X. Zeng, J. Sperry, B. Xu, Y.
Sun, X. Tang, T. Lei, L. Lin, J. Catal. 2020, 381, 570-578.
a) M. Mascal, ACS Sustainable Chem. Eng. 2019, 7,
5588-5601; b) R.-J. van Putten, J. C. van der Waal, E. de
Jong, C. B. Rasrendra, H. J. Heeres, J. G. de Vries, Chem.
Rev. 2013, 113, 1499-1597.
[3]
[17]
[18]
[4]
[5]
W. N. Haworth, W. G. M. Jones, J.chem.soc 1944,
667-670.
M. Mascal, E. B. Nikitin, Angew. Chem. Int. Ed. 2008, 47,
7924-7926.
[6]
[7]
M. Mascal, S. Dutta, Green Chem. 2011, 13, 40-41.
a) M. Mascal, S. Dutta, I. Gandarias, Angew. Chem. Int. Ed.
2014, 53, 1854-1857; b) F. Chang, S. Dutta, M. Mascal,
Chemcatchem 2017, 9, 2622-2626.
[19]
[20]
[8]
[9]
[10]
M. Mascal, ChemSusChem 2015, 8, 3391-3395.
F. HJH, G. M, J. Chem. Soc., Trans. 1901, 79, 807-816.
H. H. Szmant, D. D. Chundury, J. Chem. Technol.
Biotechnol. 1981, 31, 205-212.
[21]
[22]
[11]
[12]
M. Mascal, E. B. Nikitin, ChemSusChem 2009, 2, 859-861.
S. W. Breeden, J. H. Clark, T. J. Farmer, D. J. Macquarrie,
J. S. Meimoun, Y. Nonne, J. E. S. J. Reid, Green Chem.
2013, 15, 72-75.
a) I. Bodachivskyi, U. Kuzhiumparambil, D. B. G. Williams,
Chempluschem 2019, 84, 352-357; b) I. Bodachivskyi, U.
Kuzhiumparambil, D. B. G. Williams, Catal. Sci. Technol.
[13]
[14]
[15]
S. B. Onkarappa, S. Dutta, ChemistrySelect 2019, 4,
7502-7506.
M. Zuo, Z. Li, Y. Jiang, X. Tang, X. Zeng, Y. Sun, L. Lin,
RSC Adv. 2016, 6, 27004-27007.
a) C. Chang, L. Deng, G. Xu, Ind. Crops Prod. 2018, 117,
197-204; b) B. Chen, G. Yan, G. Chen, Y. Feng, X. Zeng, Y.
Sun, X. Tang, T. Lei, L. Lin, BMC Energy 2020, 2, 1-13.
a) H. Yamamoto, K. Futatsugi, Angew. Chem. Int. Ed.
2005, 44, 1924-1942; b) I. Bodachivskyi, U.
Kuzhiumparambil, D. B. G. Williams, Fuel Process.
2019,
9,
4693-4701; c) I. Bodachivskyi,
U.
Kuzhiumparambil, G. W. D. Bradley, ChemistryOpen 2019,
8, 1316-1324.
a) Y. Jiang, X. Zeng, R. Luque, X. Tang, Y. Sun, T. Lei, S.
Liu, L. Lin, ChemSusChem 2017, 10, 3982-3993; b) N.
Ding, X. Song, Y. Jiang, B. Luo, X. Zeng, Y. Sun, X. Tang,
T. Lei, L. Lin, Sustainable Energy Fuels 2018, 2,
2206-2214.
[23]
[24]
[16]
A. Satlewal, R. Agrawal, S. Bhagia, J. Sangoro, A. J.
Ragauskas, Biotechnol. Adv. 2018, 36, 2032-2050.
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10.1002/cssc.202002631
ChemSusChem
COMMUNICATION
Entry for the Table of Contents
Synthesis of CMF with 3c-DES：A novel method for the synthesis of CMF based on 3c-DES consisting ChCl, AlCl3·6H2O, and oxalic
acid was developed. The dependence on concentrated acid was eliminated, providing a green and efficient synthetic route for CMF
production.
6
This article is protected by copyright. All rights reserved.