N,N-DIFORMYLTRIFLUOROMETHANESULFONAMIDE
1915
1
one early publication on the synthesis of N-formyl-
arenesulfonamides ArSO2NHCHO by reaction of
arenesulfonamide sodium salts ArSO2NHNa with
formic acid esters HCOOR [7]. Diformyl derivatives
of sulfonamides were not reported previously. As
concerns N-formyl-substituted carboxylic acid amides,
only N,N-diformylformamide HCON(CHO)2 (triform-
amide) and N,N-diformylacetamide HCON(CHO)2
were reported [8]. Taking the above stated into
account, we tried to synthesize compound II as target
product under various conditions. Compound II can be
separated from excess formamide only by column
chromatography. The best result was obtained by
reacting trifluoromethanesulfonamide sodium salt
CF3SO2NHNa with formamide in the presence of
a catalytic amount of CuI. An attempt to effect
formylation of trifluoromethanesulfonamide by heating
with formic acid in boiling toluene with simultaneous
removal of water (as in the formylation of amines) [9]
was unsuccessful due to extremely low basicity of tri-
fluoromethanesulfonamide which was recovered from
the reaction mixture.
1328, 1317, 1215, 1132, 962, 770, 649, 601. H NMR
spectrum: δ 8.73 ppm, s (CHO). 13C NMR spectrum,
δC, ppm: 120.37 q (CF3, JCF = 323.5 Hz), 170.55
(CHO). 19F NMR spectrum: δF –79.39 ppm. Found:
m/z 204.9656 [M]+. C3H2F3NO4S. Calculated:
M 204.9657.
Reaction of trifluoromethanesulfonamide
sodium salt with formamide. A mixture of 5 g
(0.029 mol) of trifluoromethanesulfonamide sodium
salt and 0.28 g (1.5 mmol) of copper(I) iodide in 50 ml
of formamide was heated under stirring for 6–8 h at
140–150°C. The mixture gradually turned blue due to
liberation of ammonia and formation of copper–
ammonia complex. The progress of the reaction was
monitored by TLC, following disappearance of initial
trifluoromethanesulfonamide. The mixture was cooled,
poured into a saturated aqueous solution of sodium
chloride, and extracted with two portions of ethyl
acetate. The extract was dried over MgSO4, and the
solvent was removed under reduced pressure. Accord-
ing to the 1H NMR data, the residue, 4.87 g, contained
~50% of target compound II together with formamide
and water. Compound II was separated from form-
amide by column chromatography on silica gel using
hexane–diethyl ether (3:1 to 1:3) and hexane–diethyl
ether–propan-2-ol (2:3:1) as eluents.
Reaction of 4,5-dibromo-1H-1,2,3-triazole with
trifluoromethanesulfonamide in the presence of
copper(I) iodide in formamide. Trifluoromethanesul-
fonamide, 1.7 g (11 mmol), and 4,5-dibromo-1,2,3-
triazole, 1.13 g (5 mmol), were dissolved in 20 ml of
formamide, 0.2 g (0.55 mmol) of dicyclohexano-18-
crown-6, 0.5 g (0.55 mmol) of potassium fluoride, and
5 mol % of copper(I) iodide were added, and 0.83 g
(5.5 mmol) of potassium carbonate was then added in
small portions (strong foaming was observed). The
mixture was heated to 110–120°C over a period of
5–6 h (vigorous evolution of ammonia was observed),
cooled, poured into a saturated aqueous solution of
sodium chloride, and extracted with two portions of
ethyl acetate. The combined extracts were dried over
MgSO4, the solvent was removed under reduced pres-
sure, and the residue, ~1.7 g of a yellow–green glassy
material, was subjected to column chromatography on
silica gel to isolate 0.16 g (13%) of compound I as
colorless crystals with mp 117°C (published data [5]:
mp 116.5–117.5°C) and ~0.3 g (13%) of compound II
as white finely crystalline powder with mp ~280°C
(sublimes).
The IR spectrum was recorded on a Bruker Vertex
70 spectrometer. The NMR spectra were measured on
a Bruker DPX 400 instrument at 400 (1H), 100 (13C),
and 376 MHz (19F) from solutions in DMSO-d6; the
chemical shifts are given relative to tetramethylsilane
(1H, 13C) or trichlorofluoromethane (19F). The progress
of reactions was monitored by TLC on Silicagel 60
UV-254 plates using hexane–diethyl ether–propan-2-ol
(2:3:1) as eluent.
The authors thank E. Kleinpeter (University of
Potsdam, Germany) for measuring the precise molec-
ular weight of compound II.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 10-03-00110).
REFERENCES
1. Shainyan, B.A. and Meshcheryakov, V.I., Russ. J. Org.
Chem., 2001, vol. 37, 1797.
2. Meshcheryakov, V.I., Shainyan, B.A., Tolstikova, L.L.,
and Albanov, A.I., Russ. J. Org. Chem., 2003, vol. 39,
p. 1517.
1-Methyl-4,5-dibromo-1H-1,2,3-triazole (I).
1H NMR spectrum: δ 4.06 ppm, s (CH3). 13C NMR
spectrum, δC, ppm: 37.01 (CH3), 114.08 (C5),
122.00 (C4).
N,N-Diformyltrifluoromethanesulfonamide (II).
IR spectrum (KBr), ν, cm–1: 2916, 2902, 1650, 1612,
3. Meshcheryakov, V.I. and Shainyan, B.A., Russ. J. Org.
Chem., 2004, vol. 40, p. 390.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 12 2011
Shainyan
