L. Zuo et al. / Journal of Fluorine Chemistry 125 (2004) 1441–1446
1445
23] were prepared according to literature procedures.
DEAD, Bu4NPF6 and OsO4 were purchased from TCI
and Acros. PPh3 and NBS were recrystallized prior to
use. Chloroform was dried over P2O5 and distilled.
removed by a rotary evaporator. The residue was diluted
with ether and stood for the crystallization of triphenylpho-
sphine oxide for 12 h. Triphenylphosphine oxide was filtered
off and the filtrate was concentrated. The residue was
purified by recrystallization in ethanol. Compound 3 was
obtained as a white crystal (13.9 g, 71% yield, mp 116–
117 8C). 1H NMR (300 MHz, CDCl3) d: 1.36 (t, J ¼ 7.2 Hz,
3H), 1.39 (t, J ¼ 7.2 Hz, 3H), 2.44–2.76 (m, 2H), 4.18 (dd, 2J
¼ 12.0, 3J ¼ 7.2 Hz), 4.35 (q, J ¼ 7.2 Hz, 2H), 4.36 (q, J ¼
Electrochemical experiments were run under atmosphere
using Bu4NPF6 (0.1 M) as electrolyte in a conventional
three-electrode cell; working electrodes were platinum
(2 mm ꢀ 7 mm) and the counter electrode was a Pt wire.
Potentials were relative to a saturated calomel electrode
(SCE) placed in a separate compartment containing the
supporting electrolyte. The conductivity measurements
were performed at room temperature by the four-probe
(Model BD-86A) method on neutral polymer peel. 1H
NMR spectra were recorded on a Bruker AM 300
(300 MHz) spectrometer with Me4Si as an internal standard.
19F NMR spectra were recorded on a Bruker AM 300
(282 MHz) spectrometer using trifluoroacetic acid as an
external standard, downfield shifts being designated as
negative. All chemical shifts (d) are expressed in ppm,
coupling constants (J) are given in Hz. Mass spectra were
recorded on a Finnigan-MAT-8430 instrument using EI
ionization at 70 eV. IR spectra were recorded on a Shimadzu
IR-440 spectrometer. UV–vis spectra were recorded on a
Varian spectrophotometer (UV CARY 100 Conc). Thermal
analyses were conducted on a Perkin-Elmer Pyrisi.
2
3
7.2 Hz, 2H), 4.51 (dd, J ¼ 12.0, J ¼ 2.1 Hz, 1H), 4.76–
4.83 (m, 1H) ppm. 19F NMR (282 MHz, CDCl3) d: À126.57
(s, 2F), À123.71 (s, 2F), À123.30 (s, 2F), À122.21 (s, 2F),
À112.95 to À112.60 (m, 2F), À81.20 (s, 3F) ppm. IR (KBr)
2998, 1699, 1506, 1457, 1390, 1145, 1008, 766 cmÀ1. MS
m/z (%) 618 (Mþ, 100), 573 (76), 545 (26), 474 (9), 169 (35);
anal. calcd. for C19H15F13O6S: C, 36.90; H, 2.45. Found: C,
36.94; H, 2.78%.
4.3. 2-(1H,1H-perfluoroheptyl)-2,3-dihydrothieno
[3,4-b]-[1,4]-dioxine-5,7-dicarboxylic acid (4)
A 1000-ml one-necked round bottom flask with a mag-
netic stirrer was charged with compound 3 (13.9 g,
22.5 mmol), THF (300 ml), water (500 ml) and KOH
(10 g, 0.18 mol). The reaction mixture was stirred at reflux
for 2 h, then cooled and THF was removed by a rotary
evaporator. The residue was poured into water (500 ml),
stirred and acidified with 3N HCl. The precipitate was
filtered and compound 4 was obtained as a white powder
(11.9 g, 94% yield). 1H NMR ( 300 MHz, d6-DMSO) d: 2.5–
3.0 (m, 2H), 4.22 (dd, 2J ¼ 12.0, 3J ¼ 6.9 Hz,1H), 4.46 (dd,
2J ¼ 12.0, 3J ¼ 2.1 Hz,1H), 4.84–4.85 (m, 1H), 13.2 (br, 1H)
ppm. 19F NMR (282MHz, d6-DMSO) d: À126.57 (s, 2F),
À123.71 (s, 2F), À123.30 (s, 2F), À122.21 (s, 2F), À112.95
to À112.60 (m, 2F), À81.20 (s, 3F) ppm. IR (KBr): 3090,
1726, 1677, 1581, 1519, 1472, 731 cmÀ1; MS m/z (%) 562
(Mþ, 100), 499 (6), 247 (2), 169 (41), 69 (43), 45 (28); anal.
calcd. for C15H7F13O6S: C, 32.04; H, 1.25. Found: C, 32.48;
H, 1.47%.
4.1. 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononane-1,2-diol
(2)
A 500 ml three-necked round-bottom flask with a mag-
netic stirrer was charged with NMNO (9.5 g, 70.6 mmol),
water (25 ml), acetone (200 ml), tert-butyl alcohol (40 ml)
and compound 1 (12.7 g, 35.3 mmol). This solution was
added osmium tetraoxide (0.706 mmol). The reaction mix-
ture was stirred at room temperature for 24 h. Then,
saturated aqueous NaHSO3 (20 ml) was added into the
reaction mixture. The mixture was extracted with ethyl
acetate, the organic layer was washed with saturated aqu-
eous NaCl and dried over anhydrous MgSO4. The solvent
was removed in vacuo. The residue was purified by column
chromatography on silica gel and with elution of hexane/
ethyl acetate (4:3) to give compound 2 (12.5 g, 90% yield,
mp 60–61 8C).
4.4. 2-(1H, 1H-perfluoroheptyl)-2,3-dihydrothieno
[3,4-b]-[1,4]-dioxine (5)
A mixture of diacid 4 (11.8 g) and copper bronze (2.96 g)
in quinoline (100 ml) was heated at 180 8C for 4 h. The
mixture was cooled and dissolved in ethyl ether and filtered.
The filtrate was washed with 6N HCl, a saturated aqueous
Na2CO3 and brine. The organic layer was dried over anhy-
drous MgSO4, filtered and evaporated, The residue was
recrystallized in ethanol to give compound 5 as a white
crystal (10.0 g, 65% yield, mp 62–63 8C). 1H NMR
4.2. Diethyl 2-(1H,1H-perfluoroheptyl)-2,3-
dihydrothieno[3,4-b]-[1,4]-dioxine-5,7-dicarboxylate (3)
A 500-ml three-necked round-bottom flask equipped with
a magnetic stirrer and a nitrogen inlet was charged with
compound 2 (12.5 g, 31.7 mmol), diethyl 3,4-dihydrox-
ythiophenedicarboxylate (8.65 g, 33.3 mmol), PPh3
(16.6 g, 63.4 mmol) and anhydrous THF (165 ml) at room
temperature. A solution of 40% DEAD in toluene (34.5 g,
79.3 mmol) was added dropwise in 40 min. The reaction
mixture was stirred 1 h at room temperature and kept at
reflux for 48 h. Then, the reaction was cooled and THF was
2
(300 MHz, CDCl3) d: 2.24–2.70 (m, 2H), 4.02 (dd, J ¼
3
2
3
12.0, J ¼ 6.9 Hz, 1H), 4.28 (dd, J ¼ 12.0, J ¼ 2.1 Hz,
1H), 4.63–4.66 (m, 1H), 6.39 (s, 2H) ppm. 19F NMR
(282 MHz, CDCl3) d: À126.57 (s, 2F), À123.71 (s, 2F),
À123.30 (s, 2F), À122.21 (s, 2F), À112.95 to À112.60 (m,