1
4
T. Hickman, D.D. DesMarteau / Journal of Fluorine Chemistry 133 (2012) 11–15
3.5. Procedure for H
2
NSO
2
(CF
2
)
4
SO
2
NH
2
nitrogen atmosphere. Then 15 mL of freshly distilled dimethyl
sulfate was syringed and injected into the flask. The reaction
was heated to 105 8C in an oil bath overnight and a 19F
NMR spectrum was taken to determine completion of the
reaction.
Cold DI water was added and the mixture was allowed to stir
overnight to decompose the excess DMS. After 12 h a light
brown solid was removed by filtration and then 10 mL of ethyl
For the bis(sulfonamide), in a 100 mL 2-neck round-bottomed
flask equipped with a stir bar, approximately 30 mL of ammonia
was condensed at ꢁ80 8C and vigorously stirred. Then 6.00 g
(
16.4 mmol) of (CF CF SO F)
2 2 2 2
was added dropwise over 5 min. The
flask was allowed to come to room temperature overnight so the
excess ammonia would evaporate. Then approximately 30 mL of
acetone was added and allowed to stir for 2 h. The solution was
3
acetate and a NaHCO solution was used to separate and dry
filtered to remove the NH
evaporation. The remaining solid was dried overnight on the
vacuum line at 105 8C. A yield of 5.78 g was obtained for a 97% yield.
4
F and the acetone was removed by rotary
the compound. After separation the ethyl acetate was removed
by vacuum. This product would not sublime as the other
monofunctional and difunctional methylated sulfonimides
did in previous experiments. The compound was a very light
tan color. The yield was 75% for a total of 4.40 g. Selected
NMR dataforthe bis(sulfonamide):
s) (note: the presence of water in low amounts will shift this signal
to near 4.0).
F
d 119.4 (t, 4F), 112.8(t,4F); d6.2
(
data for 6:
.65 (s).
F H
d 73.7(s, 6F), 107.0 (s, 12F), 119.9 (s, 12F); d
3
2 2 4 2
3.6. Procedure for (Na)HNSO (CF ) SO NH(Na)
3
.8.3. Preparation of tetramer RTILCF
N(MMIM)SO (CF SO N(MMIM)SO
In a 50 mL round bottom flask with a stir bar, 30 mL of CHCl
3
SO
2
N(MMIM)SO
2
(CF
2
)
4
SO
2
The sodium salt is obtained by neutralizing the sulfonamide
with ca. 1.0 N NaOH solution to a pH of 8.4 and then drying on the
2
)
2 4
2
2
(CF
2 4
)
SO N(MMIM)SO
2
2
–CF
3
(11)
3
vacuum line at 100 8C overnight. NMR data for the disodium salt of
was added with 3.00 g (2.2 mmol) of the methylated tetramer.
Then 0.87 g (10.5 mmol) of methyl imidazole was added. The
the bis(sulfonamide):
.7. Procedure for Me
The disodium salt of the bis(sulfonamide) (3.0 g, 7.4 mmol) was
d
F
119.3 (t, 4F), 113.5 (t, 4F);
d
H
4.0 (s).
C
mixture was refluxed at 75 8C overnight. The CHCl
3
was
3
3
SiN(Na)SO (CF SO N(Na)SiMe
2
2
)
4
2
3
(7)
decanted and the IL was dried under dynamic vacuum line
for14 h at 75 8C to remove excess methyl imidazole and
moisture. The yield was 98% for a total of 3.65 g. Selected data
mixed with 40 mL of very dry acetonitrile in a 250 mL heavy-
walled flask equipped a Teflon Ace Thread connection and a
for 11:
d
F
78.6 (s, 6F), 112.2 (s, 12F), 119.4 (s, 12F);
d
H
8.35
1
(
1H, s), 7.30 (2H, s), 3.80 (6H, s). T
g
= ꢁ43 8C, T
m
= 58 8C,
reflux jacket with a Teflon-glass valve at the top. Then 20 mL of
HMDS was added and the mixture was refluxed in a closed system
with vigorous stirring for 4 days. The excess HMDS and solvent
were removed under dynamic vacuum and the white solid was
dried under dynamic vacuum at 120 8C overnight. A 100% yield is
T
d
= 459 8C.
Acknowledgement
assumed for the next step. Selected data for 7:
t, 4F); 2.0 (s).
d
F
119.2 (t, 4F), 113.4
The financial support of this research by the National Science
Foundation and the Tobey-Beaudrot Endowment (D.D.D.) is
gratefully acknowledged.
(
d
H
3.8. Procedure for
FSO (CF SO N(Na)SO (CF ) SO N(Na)SO (CF ) SO F (8)
2
2
)
4
2
2 2 4 2 2 2 4 2
Very dry acetonitrile (75 mL) was vacuum transferred into the
Appendix A. A bit of history
flask above containing 7 (4.1 g, 7.4 mmol). The difluoro compound
6
(18 g, 25 mmol) was dried over P
4
O
10 and freshly distilled before
Diplomatic relations between China and the US were estab-
lished in early 1979. Prior to this historic event, there were many
activities in anticipation of increased scientific exchange. In 1977, I
learned that one of the last US educated PhD in Chemistry was Prof.
Huang Wei-Yuan who received his degree at Harvard in 1952 and
returned to China in 1955, where he began work in fluorochemicals
(C&EN, May 16, 1977, p. 30). As part of improved scientific
exchange the American Chemical Society was planning to have a
Chinese delegation attend the ACS-Japan Chemical Society meeting
in Hawaii in April 1979 as the first Chinese to attend an ACS
meeting. I was Co-chair of the 4th ACS Winter Conference on
Fluorine Chemistry to be held in January 1979 in Daytona Beach,
FL. I began correspondence in 1978 to invite Prof. Huang Wei-Yuan
to this meeting and make the ACS Fluorine Division the first to
have Chinese participants at an ACS sponsored meeting. My efforts
were successful and three scientists from the Shanghai Institute of
Organic Chemistry, deputy director Huang Wei-Yuan, research
fellow Chen Ching-Hun and deputy chief engineer Feng Yun-Kung
attended (C&EN, Jan. 29, 1979, p. 8). As part of their visit to the US,
they also visited several industrial and academic laboratories in the
US including my university, Kansas State University (see picture). It
was the beginning of an excellent scientific and personal
relationship.
use. It was then vacuum transferred into the flask. The reaction
mixture was slowly brought to room temperature and slowly
heated to reflux. The clear solution was kept at 120 8C for 7 days.
The solvent and excess 6 were distilled out under dynamic
vacuum. The remaining off-white sold was dried at 120 8C under
dynamic vacuum overnight. The isolated yield of 8 was 94%, 7.6 g.
19
Selected data for 8: F NMR (CD
3 F
CN, ppm) d 106.5(m, 4F),
1
12.3(m, 8F), 119.3(m, 12F), +46.6(s, 2F).
3
.8.1. Preparation of tetramer sodium salt CF
SO N(Na)SO (CF SO N(Na)SO (CF SO N(Na)SO
To the 250 mL heavy-walled flask containing compound 8 (7.6 g,
.5 mmol)CF SO N(Na)Si(CH (3.4 g,14.0 mmol)wasaddedwhile
3
SO
2 2 2
N(Na)SO (CF )
4
2
2
2
)
4
2
2
2
)
4
2
2
3
CF (9)
6
3
2
3 3
)
insidea drybox. Dryacetonitrile(ca. 50 mL)wasvacuumtransferred
to the flask using a vacuum line. The mixture was then heated at
1
00 8Cfor4days. The acetonitrileand product trimethylsilylfluoride
were then removed under dynamic vacuum at 100 8C and the white
solid was dried at 100 8C under dynamic vacuum for 4 h. Selected
data for 9: d 78.6(s, 6F), 112.2 (s, 12F), 119.3 (s, 12F).
F
3.8.2. Preparation of methylated tetramer salt CF
3
SO
2
N(CH
)SO
3
)SO
CF
2
(CF SO N(CH )SO (CF SO N(CH )SO (CF SO N(CH
)
2 4
2
3
2
)
2 4
2
3
2
)
2 4
2
3
2
3
(10)
The sodium sulfonimide salt 9 (6.00 g, 4.29 mmol) was placed
in a 25 mL flask equipped with a stopcock adapter under a