Pooput et al.
7.02 (d, J ) 8.4 Hz, 2H), 6.98 (d, J ) 8.7 Hz, 2H), 5.50 (d, J )
9.9 Hz, 1H), 4.92 (m, 1H), 2.34 (s, 3H), 2.29 (m, 3H); 19F NMR
δ -81.42 (s, 3F), -120.72 (dd, J1 ) 291.6 Hz, J2 ) 12.6 Hz, 1F),
-122.78 (dd, J1 ) 291.6 Hz, J2 ) 12.6 Hz, 1F). Anal. Calcd for
C17H16F5NO2S: C, 51.91; H, 4.07; N, 3.56. Found: C, 51.72; H,
4.02; N, 3.50.
4-Methyl-N-[3,3,3,2,2-pentafluoro(4-chlorophenyl)propyl]-
benzenesulfonamide (5c): white solid (70% yield); mp 168-169
°C; 1H NMR δ 7.51 (d, J ) 8.4 Hz, 2H), 7.21 (d, J ) 8.4 Hz, 2H),
7.13 (d, J ) 8.4 Hz, 2H), 7.05 (d, J ) 8.4 Hz, 2H), 5.24 (d, J )
9.3 Hz, 1H), 4.98 (m, 1H), 2.38 (s, 3H); 19F NMR δ -81.39 (s,
3H), -120.35 (dd, J1 ) 293.7 Hz, J2 ) 13.5 Hz, 1F), -123.33
(dd, J1 ) 293.7 Hz, J2 ) 13.5 Hz, 1F). Anal. Calcd for C16H13-
ClF5NO2S: C, 46.40; H, 3.141; N, 3.38. Found: C, 46.26; H, 3.12;
N, 3.36.
Butyl trifluoromethyl sulfide (7b):5,39 1H NMR δ 2.69 (t, J )
7.3 Hz, 2H), 1.66 (quintet, J ) 7.4 Hz, 2H), 1.42 (sextet, J ) 7.4
Hz, 2H), 0.92 (t, J ) 7.4 Hz, 3H); 19F NMR δ -41.50 (s, 3F).
General Synthesis of Pentafluoroethyl Thio- and Seleno-
ethers: Phenyl Pentafluoroethyl Sulfide (9a). Using a procedure
identical to that above, diphenyl disulfide (0.8 g, 3.68 mmol) and
pentafluoroethyl iodide (3.8 g, 15.45 mmol) in 10 mL of anhydrous
DMF were allowed to react with TDAE (2 mL, 8.1 mmol), after
which the crude product was purified by silica gel chromatography
(CH2Cl2/hexanes ) 1:9) to give phenyl pentafluoroethyl sulfide
(9a) in a yield of 99%:35 19F NMR δ -83.0 (t, JFF ) 3.1 Hz, 3F),
-92.3 (q, JFF ) 3.1 Hz,2F).
4-Pyridyl Pentafluoroethyl Sulfide (9e): 1H NMR δ 8.51 (dd,
J1 ) 4.8 Hz, J2 ) 2.0 Hz, 2H), 7.37 (dd, J1 ) 4.7 Hz, J2 ) 1.75
Hz, 2H); 19F NMR δ -82.95 (t, JFF ) 2.14 Hz, 3F), -90.8 (q, JFF
) 2.14 Hz, 2F). Anal. Calcd for C7H4F5NS: C, 36.68; H, 1.75; N,
6.11. Found: C, 36.70; H, 1.80; N, 6.21.
General Procedure for Perfluorobutylation of Tosyl Imines:
4-Methyl-N-[5,5,5,4,4,3,3,2,2-nonafluoro(4-methylphenyl)propyl]-
benzenesulfonamide (6a). In a manner similar to that used for the
pentafluoroethylation reaction, N-(4-methylbenzylidene)-p-meth-
ylbenzenesulfonamide (0.273 g, 1 mmol) and nonafluorobutyl
iodide (0.38 mL, 2.2 mmol) in 6 mL of anhydrous DMF were
allowed to react with TDAE (0.51 mL, 2.2 mmol). In this case, a
dark brown oil separated during the acidification process, and the
solution was stirred for several additional hours as more brown,
viscous oil was formed. Ether (30 mL) was added to dissolve the
oil, the two phases were separated, and the ether solution was
washed 3 times with water to eliminate remaining DMF. The ether
phase was then dried over anhydrous MgSO4 and the solvent
removed by vacuum. The pale yellow, crude product (6a) was
recrystallized from toluene to afford 0.189 g of a white solid
Phenyl pentafluoroethyl selenide (11a):37 19F NMR δ -84.7
(t, JFF ) 3.2 Hz, 3F), -92.1 (q, JFF ) 3.2 Hz, 2F).
4-Chlorophenyl pentafluoroethyl selenide (11b): 1H NMR δ
7.39 (d, J ) 8.1 Hz, 2H), 7.27 (d, J ) 8.1 Hz, 2H); 19F NMR δ
-84.7 (t, JFF ) 3.2 Hz, 3F), -92.1 (q, JFF ) 3.2 Hz, 2F). Anal.
Calcd for C8H4ClF5Se: C, 31.02; H, 1.29; N, 0.0. Found: C, 31.12;
H, 1.32; N, 0.0.
General Synthesis of Nonafluorobutyl Thio- and Seleno-
ethers: Phenyl Nonafluorobutyl Sulfide (10a).34 Using a proce-
dure identical to the previous one, diphenyl disulfide (0.8 g, 3.68
mmol) and nonafluorobutyl iodide (1.4 mL, 15.45 mmol) in 10
mL of anhydrous DMF were allowed to react with TDAE (2 mL,
8.1 mmol), and the crude product was purified by silica gel
chromatography (CH2Cl2/hexanes ) 1:9) to give phenyl nonafluo-
robutyl sulfide (10a) in the yield of 70%. The properties of this
1
(50%): mp 148-149 °C; H NMR δ 7.51 (d, J ) 8.4 Hz, 2H),
7.09 (d, J ) 8.1 Hz, 2H), 7.00 (m, 4H), 5.33 (d, J ) 9.9 Hz, 1H),
5.04 (m, 1H), 2.34 (s, 3H), 2.29 (s, 3H); 19F NMR δ -81.4 (t, J )
9.9, 3F), -117.0 (dm, J1 ) 301.5 Hz,, 1F), -118.9 (dm, J1 ) 301.5
Hz, 1F), -121.5 (m, 2F), 126.5 (m, 2F). Anal. Calcd for C19H16F9-
NO2S: C, 46.21; H, 3.24; N, 2.84. Found: C, 46.24; H, 3.19; N,
2.82.
product were consistent with those reported in the literature:34 19
F
NMR δ -81.3 (t, JFF ) 10.2 Hz, 3F), -87.4 (m, 2F), -120.5 (m,
2F), -125.9 (m, 2F).
Butyl nonafluorobutyl sulfide (10c): 1H NMR δ 2.69 (t, J )
7.3 Hz, 2H), 1.66 (quintet, J ) 7.6 Hz, 2H), 1.42 (sextuplet, J )
7.6 Hz, 2H), 0.93 (t, J ) 7.3 Hz, 3H); 19F NMR δ -81.35 (t, JFF
) 8.5 Hz, 3F), -87.7 (m, 2F), -121.0 (m, 2F), -125.5 (m, 2F).
Anal. Calcd for C8H9F9S: C, 31.17; H, 2.92; N, 0.0. Found: C,
31.11; H, 2.88; N, 0.0.
4-Methyl-N-[5,5,5,4,4,3,3,2,2-nonafluoro-(4-chlorophenyl)pro-
pyl]benzenesulfonamide (6b): white solid (70% yield); mp 140-
141 °C; 1H NMR δ 7.50 (d, J ) 8.4 Hz, 2H), 7.18 (d, J ) 8.7 Hz,
2H), 7.11 (d, J ) 7.8 Hz, 2H), 7.04 (d, J ) 8.4 Hz, 2H), 5.60 (d,
J ) 9.9 Hz, 1H), 5.07 (m, 1H), 2.37 (s, 3H); 19F NMR δ -81.4 (t,
J ) 11.1 Hz, 3F), -116.5 (dm, J1 ) 304.8 Hz, 1F), -119.4 (d, J1
) 304.8 Hz, 1F), -121.4 (m, 2F), 126.55 (m, 2F). Anal. Calcd for
C18H13ClF9NO2S: C, 42.04; H, 2.53; N, 2.72. Found: C, 41.90;
H, 2.46; N, 2.69.
Phenyl nonafluorobutyl selenide (12a):37 19F NMR δ -81.5
(t, JFF ) 10.7 Hz, 3F), -87.3 (m, 2F), -119.1 (m, 2F), -126.05
(m, 2F).
Phenyl trifluoromethyl selenide (8a):38 1H NMR δ 7.60-7.26
(5H, m); 19F NMR δ ) -36.6 (3F, s).
General Procedure of the Synthesis of the Trifluoromethyl
Sulfides: Phenyl Trifluoromethyl Sulfide (7a).5,35,38 To the usual
25 mL, three-neck, round-bottom flask arrangement were added
diphenyl disulfide (0.8 g, 3.68 mmol) and 10 mL of anhydrous
DMF, and the solution was cooled to -5 °C at which time TDAE
(2 mL, 8.1 mmol) was added. Then CF3I (3.6 g, 18.4 mmol) was
introduced to the mixture in the usual manner, with no irradiation
required, upon which the reaction mixture became increasingly dark
orange, with a white precipitate forming after few minutes. The
reaction mixture was kept under 0 °C for about 30 min and was
then allowed to warm slowly to the room temperature. The reaction
mixture was then stirred at room temperature for 2 h, after which
the orange solution was filtered and the solid washed with diethyl
ether. The DMF solution was then hydrolyzed with water and was
extracted with ether (3 times). The combined ether layers were
washed with brine and dried over MgSO4. The solvent was removed
and the crude product was purified by silica gel chromatography
(CH2Cl2/hexanes ) 1:9) to give phenyl trifluoromethyl sulfide (7a)
in a yield of 89%:5,35,38 1H NMR δ 7.60-7.19 (m, 5H); 19F NMR
δ -43.20 (s, 3F).
Acknowledgment. Support of this work in part by the
National Science Foundation is acknowledged with thanks. We
also thank Dr. Viacheslav Petrov and Dr. Bruce Smart of DuPont
for a generous sample of C2F5I and Dr. Wei Xu for obtaining
the melting points of all of the imine adducts.
Supporting Information Available: General experimental
methods and characterization data for compounds 2c,e,f,g; 5d-g;
6c-f; 7c-e; 9b-d; 10b,d,e; 12b; and 8b. This material is available
JO060250J
(39) Ignatev, N. V.; Boiko, V. N.; Yagupolskii, L. M. J. Org. Chem.,
USSR 1985, 21, 592-592.
(40) Yagupolskii, L. M.; Kondratenko, N. V.; Sambur, V. P. Synthesis
1975, 721-723.
(41) These highly volatile compounds were identified and their yields
1
determined only by H and 19F NMR spectra of reaction mixtures.
(42) Barton, D. H. R.; Lacher, B.; Zard, S. Z. Tetrahedron 1986, 47,
2325-2328.
(43) Hartung, J.; Kneuer, R.; Laug, S.; Schmidt, P.; Spehar, K.; Svoboda,
I.; Fuess, H. Eur. J. Org. Chem. 2003, 4033-4052.
(38) Billard, T.; Roques, N.; Langlois, B. R. J. Org. Chem. 1999, 64,
3813-3820.
3568 J. Org. Chem., Vol. 71, No. 9, 2006