REACTION OF N,N'-METHYLENEBIS(TRIFLUOROMETHANESULFONAMIDE) WITH STYRENE
735
Scheme 2.
H O
[O]
2
4
+
TfNHCH
OH
1
3
2
[
O]
4
+
CO + H O
2 2
+
[O]
[I ]
OH
I
5
+
4
6
Ph
Ph
data. The effect of the temperature is manifested in that
the total isolable yield of products 3–6 decreases from
stirred for a day under argon. The solvent was then
removed in a vacuum, the residue was dissolved in
60 mL of ether and treated with aqueous Na S O , and
8
0% at –30°C to 51% at room temperature, probably,
2
2
3
because of a lower tarring of the reaction mixture at
the negative temperature, and also the 3 : 4 : 5 : 6
product changes from 29 : 26 : 19 : 6 at –30°C to
the extract was dried over CaCl . The solvent was
2
removed in a vacuum, and the residue was treated with
ether. The residue insoluble in ether was recrystallized
from hexane to obtain 0.60 g (29%) of N,N'-bis-
(trifluoromethanesulfanyl)urea 3. The liquid residue
(1.6 g) was applied on a column of silica gel
(AcrosOrganics, 0.060–0.200 nm) and eluted with
hexane to isolate 0.10 g (6%) of 2-iodo-1-phenyl-
ethanol 6, then with hexane–ether (1 : 1) to isolate 0.50 g
(26%) of triflamide 4, and finely with pure ether to
isolate 0.50 g (19%) of N-[2-phenyl-2-(trifluorometha-
nesulfonyl)aminoethyl]triflamide 5.
1
0 : 18 : 8 : 15 at room temperature. Compound 3 was
previously prepared by hydrolysis of bis(triflyl)-
chloroformamidine TfNHC(Cl)=NTf [9]. It was
reasonable to suggest that substituted urea 3 is
formed by the oxidation of N,N'-methylenebis(tri-
fluoromethanesulfonamide), which occurs under
the reaction conditions and does not involve styrene.
To obtain evidence for this suggestion, we performed
this reaction under the same conditions (at –30°C)
but in the absence of styrene and isolated compounds
Oxidation of N,N'-methylenebis(trifluorometha-
nesulfonamide). A solution of NaI (0.72 g, 4.8 mmol)
and N,N'-methylenebis(trifluoromethanesulfonamide)
3
(77%) and 4 (21%) with a nearly quantitate
total yield. This result implies independent
formation of urea 3 and products 4−6 and allows
us to propose the following reaction mechanism
(
0.50 g, 1.6 mmol) in 30 mL of acetonitrile was cooled
to –30°C, after which t-BuOCl (0.52 g, 4.8 mmol)
was added dropwise to it. The mixture was stirred for a
day under argon. The solvent was then removed in
a vacuum, the residue was dissolved in 30 mL of
ether, treated with aqueous Na S O , and the extract
(
Scheme 2).
Thus, the reaction of N,N'-methylenebis(trifluoro-
methanesulfonamide) with styrene in the oxidative
system t-BuOCl/NaI involves two independent routes.
The first consists in the oxidation of the reagent to
N,N'-bis(trifluoromethanesulfonyl)urea, as well as its
hydrolysis with traces of water to triflamide and an
N-(hydroxymethyl)triflamide intermediate, and the
second, in the bistriflamidation of styrene and
formation of a iodo alcohol, as we described
earlier.
2
2
3
was dried over CaCl . The solvent was removed in a
2
vacuum, and the residue (0.3 g) was recrystallized
from hexane to obtain 0.20 g (77%) of N,N'-bis-
(trifluoromethanesulfonyl)urea 3 and 0.05 g (21%) of
triflamide 4.
N,N'-Bis(trifluoromethanesulfonyl)urea (3).
Yield 0.5 g (29%). White water-soluble powder, mp
123.8–124.7°C (from hexane; 129–131°C [9]). IR
Reaction of N,N'-methylenebis(trifluorometh-
anesulfonamide) with styrene in an oxidative
system. A solution of N,N'-methylenebis(trifluorome-
thanesulfonamide) (2.00 g, 6.5 mmol), styrene (0.68 g,
–
1
spectrum, ν, cm : 3232, 2691, 1952, 1787, 1729,
1630, 1543, 1430, 1328, 1204, 1126, 976, 817, 757,
1
645, 595, 561, 500, 486. Н NMR spectrum (CD CN),
3
1
3
6
.5 mmol), and NaI (2.93 g, 19.5 mmol) in 60 mL of
δ, ppm: 8.72 s (1H, NH). C NMR spectrum
(CD CN), δ, ppm: 119.82 q (CF , J 320.3 Hz),
174.54 (C=O). F NMR spectrum (CD CN): δ
acetonitrile was cooled to –30°C and protected from
light, after which t-BuOCl (2.12 g, 19.5 mmol) was
added dropwise to it in the dark. The mixture was
3
3
1
9
3
–79.7 ppm.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 5 2019
Moskalik, M. Yu.
