C. Thiehoff et al. / Journal of Fluorine Chemistry 182 (2016) 121–126
125
[(Fig._4)TD$FIG]
Fig. 4. A: X-ray structure of sulfide 1h. Only one molecule of two found in the asymmetric unit is shown. Thermal elipsoides shown at the 30% probability level. B: Dimeric
structure of 1h between the two molecules found in the asymmetric unit involving O–H . . . H interactions [11].
76.8 (d, 1JCF = 170.4, C1), 58.2 (d, 2JCF = 19.6, C2) ppm; 19F NMR (282
[(Fig._5)TD$FIG]
MHz, CDCl3)
ppm; IR (ATR)
d
= ꢀ220.99 (1F, tdd, 2JHF = 46.6, 3JHF = 30.1, 19.5, F-C1)
~
n
= 3055w, 2967w, 2901w, 1474m, 1443m, 1389m,
1088m, 1038s, 991s, 957m, 829w, 745s, 691s, 633m cmꢀ1; HRMS
(ESI): m/z: 195.0253 ([M + Na]+, calcd. for C8H9FOSNa+:195.0250).
4.3. ((2-Fluoroethyl) sulfonyl) benzene (3e)
A solution of 1e (20 mg, 0.13 mmol, 1.0 eq.) in CH2Cl2 (2.5 ml)
was cooled to 0 ꢁC and mCPBA (ꢆ77%, 74 mg, 0.32 mmol, 2.5 eq.)
was added. After stirring for 7 h under an atmosphere of argon
while warming to rt, the mixture was washed with aq. Na2SO3 (5%,
6 ml), aq. sat. NaHCO3 (2 ꢂ 5 ml) and brine. The separated organic
layer was dried over Na2SO4 and concentrated under reduced
pressure. Separation by column chromatography on silica gel (CyH/
EtOAc 3:1) afforded the desired product as colourless oil (20 mg,
82%).
Fig. 5. Putative intramolecular interactions (dipole minimization: arrow; Coulomb
interaction: dashed) in the g+ (minor) and gꢀ (major) sulfoxide conformers (n = 1).
Rf = 0.35 (pentane); 1H NMR (400
7.38 (2H, m, H-C5), 7.34–7.28 (2H, m, H-C4), 7.26–7.21 (1H, m, H-
MHz, CDCl3) d= 7.42–
2
3
C6), 4.54 (2H, dt, JHF = 47.0, JHH = 6.8, H-C1), 3.21 (2H, dt,
3JHF = 17.0, JHH = 6.9, H-C2) ppm; 13C NMR (101 MHz, CDCl3)
3
Rf = 0.25 (CyH/EtOAc 1:1); 1H NMR (400 MHz, CDCl3)
7.92 (2H, m, H-C5), 7.70-7.65 (1H, m, H-C6), 7.61–7.55 (2H, m, H-
d= 7.96–
d
= 134.9 (C3), 130.4 (2C, C5), 129.3 (2C, C4), 127.0 (C6), 81.7 (d,
2
1JCF = 172.5, C1), 33.8 (d, JCF = 21.6, C2) ppm; 19F NMR (282 MHz,
2
3
CDCl3) d
= -212.43 (1F, tt, 2JHF = 47.0, 3JHF = 17.0, F-C1) ppm; IR (ATR)
C4), 4.80 (2H, dt, JHF = 46.5, JHH = 5.6, H-C1), 3.52 (2H, dt,
3
~
n
3JHF = 22.0, JHH = 5.6, H-C2) ppm; 13C NMR (101 MHz, CDCl3)
= 3060w, 2963w, 2895w, 1583m, 1480m, 1439m, 1404w, 1385w,
d
= 139.5 (C3), 134.2 (C6), 129.5 (2C, C4), 128.2 (2C, C5), 77.2 (d,
1288w,1231w,1197w,1088w,1059m,1024m,1006m, 986m, 955m,
898w, 813w, 737s, 689s cmꢀ1; GC-MS (EI): tR = 8.63 min, m/z: 156.0
(M+). Spectroscopic data are in agreement with previous literature
[13].
2
1JCF = 173.1, C1), 56.9 (d, JCF = 21.5, C2) ppm; 19F NMR (282 MHz,
2
3
CDCl3)
(ATR)
d
~
n
= ꢀ221.42 (1F, tt, JHF = 46.5, JHF = 22.0, F-C1) ppm; IR
= 2932w, 1447m, 1389w, 1319m, 1292m, 1246w, 1184w,
1142s, 1088m, 1065m, 999m, 961w, 768m, 729s, 687s, 594m cmꢀ1
;
for
([M + Na]+,
calcd.
4.2. ((2-Fluoroethyl) sulfinyl) benzene (2e)
HRMS
(ESI):
m/z:
211.0209
C8H9FO2SNa+:211.0199)
A solution of 1e (76 mg, 0.49 mmol, 1.00 eq.) in CH2Cl2 (8 ml)
was cooled to 0 ꢁC and mCPBA (ꢆ77%, 118 mg, 0.51 mmol, 1.05 eq.)
was added. After stirring for 16 h under an atmosphere of argon
while warming to rt, the mixture was washed with aq. sat. NaHCO3
(6 ml), brine, was dried over Na2SO4 and concentrated under
reduced pressure. Separation by column chromatography on silica
gel (CyH/EtOAc 1:1) afforded the desired product as colourless oil
(49 mg, 58%).
4.4. S-(2-Fluoroethly) ethanethioate (4) [7]
2-Fluoroethane tosylate (0.4 g, 1.8 mmol, 1.0 eq.) and potassium
thioacetate (0.25 g, 2.2 mmol, 1.2 eq.) were suspended in acetone
(6 mL) and heated to 70 ꢁC for 4 h. The reaction mixture was filtered
and the residual was washed with copious amounts of acetone. The
brown filtrate was concentrated under reduced pressure. Subse-
quently, the residual was partitioned between H2O and Et2O and
the organic layer was dried over MgSO4 and concentrated under
reduced pressure. Fractional distillation (40 mbar, 50 ꢁC) afforded
the title product as a colourless liquid (0.1 g, 44%). Spectroscopic
data in agreement with previously published ones [6].
Rf = 0.25 (CyH/EtOAc 1:1); 1H NMR (400 MHz, CDCl3)
7.63 (2H, m, H-C5), 7.57–7.51 (3H, m, H-C4/C6), 4.92 (1H, dddd,
d
= 7.67–
2
3
2JHF = 46.9, JHH = 10.5, JHH = 8.5, 3.8, H-C1), 4.72 (1H, dddd,
2
3
2JHF = 46.3, JHH = 10.5, JHH = 4.8, 4.6, H-C1), 3.11 (1H, dddd,
2
3
3JHF = 19.5, JHH = 13.8, JHH = 8.4, 4.6, H-C2), 3.07 (1H, dddd,
2
3
3JHF = 30.1, JHH = 13.9, JHH = 4.8, 3.8, H-C2) ppm; 13C NMR (101
1H NMR (400 MHz, CDCl3)
H-C1), 3.19 (2H, dt, JHF = 21.5, JHH = 6.2, H-C2), 2.36 (3H, s, H-C4)
d
= 4.50 (2H, dt, 2JHF = 46.9, 3JHH = 6.2,
3
3
MHz, CDCl3) = 143.5 (C3), 131.5 (C6), 129.6 (2C, C4),124.0 (2C, C5),
d