40
N.O. Brace / Journal of Fluorine Chemistry 102 (2000) 21±41
added to the thick gel. After 16.5 h, the mixture is no longer
stirring; a sample is dried in air; wt 0.08 g. When slurried in
dil. HNO3, collected and dried again; mp 164±1748C, gas
evolution at ca. 2108C. IR: C=O (COOH bonded and free) at
1720 and 1690 cm 1; at least two compounds are present:
8c has nC=O of COOH at 1700 cm 1. The mixture is evapd
to dry solid, 1.06 g, slurried with chloroform (10 ml) and dil.
HC1 (20 ml), collected, rinsed with water and dried; wt
1.170 g, mp (sinter 1728C ) 173±196±2108C. The mixture of
8c is fractionally crystallized from acetone (20 ml), ®ltered
at the boil from insoluble solid (0.0600 g) and cooled. Solid
fractions collected are: (1) (8c), 0.4528 g, mp 189±1908C
and 200±2018C, and (2) (8c), 0.0482 g, total 47.4% con-
version; (3) (16), 0.0709 g, 6.0% conversion, mp 157±
1588C; (4) 0.0310 g, mp (sinter 103) 124±1638C; (5)
0.0333 g, mp 147±2008C; (6) evapd off remaining solvent,
soft solid and oil, 0.53 g. Fractions 4±6 appear to be
mixtures of 8c, 16 and higher telomers, total conversion
50% calcd as telomer 16. This gives a total of 100%
recovery of material. A 0.10 g portion of 8c is recrystallized
(tetrahydrofuran, 5 ml); fractions of 8c, 0.066 and 0.0100 g,
mp 190.5±194±1978C, and lower melting mixtures. IR: 8c
nC=O, 1700 cm 1. NMR (8c, C8): RFCH2(A)CH2(B)-
SO2CH2(C)CH2(D)COOH. d2.80, 2H, m, CH2(A); d3.04,
2H, m, CH2(D); d3.57, 4H, CH2 (B), CH2 (C). Elemental
analysis of 8c (C8) is given in Table 2, entry 3. IR: Telomer
16 (C8) nCH, 3000, 2980, 2960, 2840; nC=O, 1722 and
prepared by oxidation of allyl 2-(per¯uorooctyl)ethyl sul-
®de in 96.4% yield, mp 97±98.58C. Anal. Calcd for
C13H9F1702S: C, 28.27; H, 1.64; F, 58.49. Found: C,
28.20; H, 1.49; F, 58.43.
12.22. Telomerization of acrylamide with 2-
(perfluorohexyl)ethanesulfinic acid
Acrylamide (6f, 3.55 g, 50.0 mmol), salt 2, C6 (2.26 g,
5.00 mmol corrected, 85% pure; mols 2: 6f 0.1), azo-bis-
valeronitrile (AIVN, 2,20-azo-bis (2,4-dimethylpentaneni-
trile); 0.0783 g, 0.31 mmol; 0.62% on 6f) and acetic acid
(0.60 g, 10 mmol) are charged to a Kontes paddle stirred
glass reactor, under nitrogen atmosphere at 258C; while
stirring, and at 288C acetonitrile (30 ml) is added. The
vessel is immersed in an oil bath kept at a constant tem-
perature, and after 10 min at 458C a solid begins to separate.
The bath temperature is raised to 508C, and after 30 min, a
translucent gel and solid is formed. The extremely thick,
white paste is stirred for 6 h at 458C, slurried in acetone
(50 ml) and collected on a Buchner funnel. The solid cake is
rinsed with acetone and dried. The telomer 15 (A) weighs
6.00 g (92.5% of the charge), and the ®ltrate is evapd to give
0.46 g (7% of the charge) of additional telomeric product 15
(B) as a soft solid. IR: (A), strong NH bands and C=O bands
of 6f and strong bands of 2 (salt) at 2960, 2920 (nCH); 1380
(nSO2); 1080 (nS=O), 1060 and 970 cm 1. Sample (B)
gives the same spectrum, with some additional bands of
6f and 2. Sample (A) dissolves in water to give a foamy,
clear solution over a little sediment. Surface tension:
0.1 wt.%, 30.4 dynes/cm; 0.01%, 52.9 dynes/cm; 0.001%,
57.9 dynes/cm. The titration with HClO4 (see below) indi-
cates 88.2% of the original titre of salt 2 is present in 15 (A);
thus, 12% or 0.60 mmol of 2 is incorporated into the
telomer. A rough calculation indicates that there is, on
the average, one sul®nate group for 83 acrylamide units
in telomer product 15 (A).
1
1695 cm or two COOH; dCH, 1430, 1410; nSO2, 1380,
1365; bands at 1090 and 1055 cm 1 not found in 8c. NMR
(16):
RFCH2(D)CH2(C)SO2
CH2(B)CH(A)(COOH)-
CH2(E)CH2(F)COOH. d2.80, 4H, m, CH2(D), CH2(E);
d3.02, 2H, m, CH2(F); d3.52, 4H, m, CH2(C), CH2(B);
d4.50, 1H, m, CH (A).
12.21. Allyl 2-(perfluorohexyl)ethyl sulfone (14, C6) by
reaction of sodium salt 2 (C6) with 3-bromo-l-propene
Sodium salt 2, C6 (9.05 g, 18.0 mmol, 90% pure; 7.0% of
C4 and 93.0% of C6 homolog), 3-bromo-l-propene (4.84 g,
40.0 mmol), (Bu)4NBr (phase transfer catalyst) (0.45 g,
1.40 mmol), water (10 ml), 1,2-dichloroethane (50 ml)
and acetone (10 ml) is stirred by magnet bar at 708C (re¯ux
temperature) for 21 h. A highly foaming mixture is formed;
the bath temperature is raised to 808C, and volatile material
(mostly 1,2-dichloroethane) is removed, bp 45±718C. A
small amount of water azeotrope, bp 718C, is obtained.
Upon cooling, the mixture is washed with water (50 ml) and
the organic layer ®ltered from a little solid. The aqueous
layer is extracted with ether (20 ml), combined with the
organic layer and evapd off to solid 14, 8.82 g; GC, 86.4%
HPLC is used to determine the chemical composition of
15. As reference materials, 6f (ret. time, 2.30 min), salt 2
(12.40 min), and sulfone 8f (C6); 15.33 min) are used (see
Section 12.18 for preparation and properties of 8f). The
column is ``Zorban ODS'', 250 by 4.6 mm. The mobile
phase (program) is 20% acetonitrile in water for 25 min,
linear to 100% acetonitrile, then hold for10 min. The ¯ow
rate is 1.4 ml/min. Detection is set at 215 nm. Samples of
10 ml are injected. The HPLC Graph 1 shows 0.13% of 6f,
no salt 2 at 12.40 min, and only traces of the adduct 8f at
15.33 min; the elution of a large number of small peaks
running from 15 to 29 min indicate a mixture of homo-
logous telomers, higher than adduct 8f. The absence of salt 2
is unaccountable.
pure, 13.6% of Bu4NBr, yield, 93.7%. IR: nCH, 3080;
1
nC=C, 1645 cm
nSO2, 1080, 1060 cm 1; dCH=CH,
NMR: RFCH2(A)CH2(B)SO2CH2(C)-
Differential thermal analysis shows that 15 (A) decom-
poses at 2908C, and there is an endotherm at 220±2508C;
this behavior is similar to that of the adduct 8f. A water
solution of 15 (A) reacts with 1% KMnO4, to give MnO2,
and titration of (A) with HClO4, and two samples of salt 2
1
970, 910 cm
.
CH(D)=CH2(E). d2.10±3.02, 2H, m, CH2(A); d3.02±3.33,
2H, m, CH2(B); d3.77, 2H, d, with broadened arms, CH2(C);
d5.3±6.4, 3H, m, CH(D)=CH2(E). A sample of pure 14 is