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DOI: 10.1002/cctc.201400023
NaBr/DMSO-Induced Synthesis of 2,5-Diformylfuran from
Fructose or 5-(Hydroxymethyl)furfural
Caroline Laugel,[a, b] Boris Estrine,*[a] Jean Le Bras,*[b] Norbert Hoffmann,[b] Sinisa Marinkovic,[a]
and Jacques Muzart[b]
2,5-Diformylfuran (DFF) was obtained by heating a solution of
5-(hydroxymethyl)furfural in DMSO. The addition of acids or
salts improved the selectivity, especially if bromides were em-
ployed. Good yields of DFF were obtained with HBr or NaBr as
the catalyst. One-pot procedures were developed from fruc-
tose, which led to DFF in medium yields. This transformation
occurs through the formation of 5-(bromomethyl)furan-2-car-
baldehyde followed by a Kornblum-type reaction. In the pres-
ence of bromide salts, the in situ formation of the catalyst in-
volves the thermolysis of DMSO and the association of the re-
sulting strong acids with the bromides.
0.75 equivalents of the catalyst.[3] A one-pot/two-step synthesis
of DFF was achieved by catalytic conversion of glucose over
CrCl3·6H2O/NaBr followed by NaVO3·2H2O-catalyzed oxidation,
and DFF was obtained in 55% yield based on glucose; the
one-pot process led to the formation of DFF in 18% yield.[4]
DFF was synthesized from glucose in 25% yield in N,N-dime-
thylformamide through isomerization, dehydration, and oxida-
tion through the stepwise addition of hydrotalcite, Amberlyst-
15, and Ru/hydrotalcite catalysts.[5] The two latter catalysts also
allowed the preparation of DFF from fructose in 49% yield.[5]
Notably, these one-pot syntheses of DFF usually require the
stepwise addition of the catalyst; the coexistence of both de-
hydration and oxidation catalysts from the initial stage of the
reactions produces low yields of DFF owing to undesired side
reactions that convert carbohydrates into humins.
2,5-Diformylfuran (DFF) is an important platform molecule that
can be synthesized from renewable resources.[1] Such a com-
pound is produced by oxidation of 5-(hydroxymethyl)furfural
(HMF), which is prepared by dehydration of carbohydrates
such as fructose. The routes reported for the synthesis of DFF
are mostly based on the oxidation of pure HMF, but its high
price limits the production of DFF. This drawback and
the low stability of HMF in organic solvents have led
to the development of one-pot procedures from fruc-
tose to avoid the isolation of HMF. DMSO is known
to promote dehydration efficiently and to stabilize
HMF, and one-pot methods have therefore been de-
veloped in such a solvent. Grushin reported the first
practical method for the synthesis of DFF directly
from fructose by using a two-step procedure involv-
ing the dehydration of fructose by an acidic resin fol-
lowed by filtration of the resin and air oxidation of
Herein, we report that simple salts, in one-pot transforma-
tions, can replace transition-metal catalysts for the conversion
of fructose or HMF into DFF in DMSO as the solvent
(Scheme 1). Preliminary mechanistic studies are also discussed.
Scheme 1. Synthesis of DFF from fructose.
the resulting HMF by vanadium catalyst at 1508C.
Thus, DFF was isolated in 45% overall yield.[2] The
one-pot synthesis of DFF from fructose was achieved in 80%
yield through the stepwise addition of the catalyst, that is,
a magnetic solid acid, Fe3O4-SBA-SO3H, and a porous manga-
nese oxide, K-OMS-2. However, the oxidation step required
The dehydration of fructose is known to occur in DMSO at
high temperature.[1a,6] This transformation is generally per-
formed in a few hours at 1508C. Upon studying the stability of
HMF in DMSO at this temperature, we observed that DFF was
produced after 18 h in 30% yield (Table 1, entry 1).[7] We sus-
pected that the decomposition products of DMSO at high tem-
perature could act as catalysts for the oxidation of HMF. Swern
observed that thermolysis of DMSO in air led to the formation
of strong acids such as sulfuric and methanesulfonic acids.[8]
We indeed observed acidification of the reaction mixture.[9] Var-
ious Brønsted acids were then evaluated as catalysts for the
oxidation of HMF in DMSO. Full conversion of HMF was ach-
ieved by using H2SO4 (30 mol%), and thermal conditions gave
better selectivity than microwave irradiation (Table 1, entries 2
and 3). HCl, HI, and PTSA·H2O (PTSA=p-toluenesulfonic acid)
[a] Dr. C. Laugel, Dr. B. Estrine, Dr. S. Marinkovic
Green Chemistry Department
Agro-industrie Recherches et Dꢀveloppements
Route de Bazancourt, Pomacle 51110 (France)
[b] Dr. C. Laugel, Dr. J. Le Bras, Dr. N. Hoffmann, Dr. J. Muzart
Institut de Chimie Molꢀculaire de Reims, UMR 7312
CNRS-Universitꢀ de Reims Champagne-Ardenne
UFR des Sciences Exactes et Naturelles, Reims 51100 (France)
Supporting information for this article is available on the WWW under
ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemCatChem 2014, 6, 1195 – 1198 1195