Â
B. Ameduri et al. / Journal of Fluorine Chemistry 92 (1998) 69±76
70
maintained at 0.6 bar and the detector and injector tempera-
tures were 2608C and 2558C, respectively. The temperature
program started from 508C and reached 2508C at a heating
rate of 158C min 1. The GC apparatus was connected to a
Hewlett Packard integrator (model 3390) which automati-
cally calculated the area of each peak on the chromatogram.
After an acidic treatment, neutralization and evaporation
of the solvent, the gross was analyzed by GC. The yield was
estimated to be 62%.
2.3. Reduction of the above iodhydrin (A) to A,1
1
The products were characterized by H, 13C and 19F-
80.0 g (0.27 mol) of tributyl stannane were dropwise
added under stirring to 88.9 g (0.26 mol) of iodohydrin A
placed in an ampoule cooled in an ice bath, saturated of
argon and equipped with a septum. The addition took
30 min, the ice bath being progressively lowered. Then,
the mixture was stirred for 3 additional hours at room
temperature. Afterwards, the reduced derivative A,1 was
distilled under reduced pressure. 47.2 g (0.225 mol) of a
clear yellow liquid was obtained (yield86.5%). Bp
808C±828C/23 mm Hg.
NMR spectroscopy at room temperature. The 19F, 13C and
1H-NMR spectra were recorded on a Bruker AC-200, -250
or WM-360 instruments, using deuterated chloroform and
CFCl3 as solvent and internal reference, respectively. The
letters s, d, t, qi and m designate singlet, doublet, triplet
quintet and multiplet, respectively. NMR simulation was
performed with gNMR software [37].
2.2. Radical addition of 1-iodo-1,2-
dichlorotrifluoroethane to allyl alcohol
4,5-dichloro-4,5,5-tri¯uoro pentanol (A,1): 1H-NMR
(CDCl3) ꢀ:1.90 (m, BB0 part of AA0BB0 system,
CH2CH2OH, 2H); 2.15 (broad signal, shifted with dilution
or to 7±9 ppm with Cl3CNCO, OH, 1H); 2.40 (m, AA0 part,
2.2.1. Reaction at atmospheric pressure
In a three necked round bottom ¯ask equipped with a
condenser and a thermometer was stirred a mixture of
171.1 g (0.617 mol) of Cl(C2F3Cl)I and 98.3 g (1.69 mol)
of allyl alcohol. The mixture was heated up to 808C and
2.30 g (0.014 mol) of AIBN was added every hour. The
reaction was monitored by GC until the quasi total con-
sumption of the iodinated reactant. Then, the iodohydrin
was distilled. 167.5 g (0.497 mol) of a yellow orange liquid
was obtained. Yield 81%. Bp64±668C/0.2 mm Hg.
2-iodo-4,5,5-tri¯uoro-4,5-dichloropentanol (A): 1H-NMR
(CDCl3) ꢀ: 2.5 (broad s, shifted with dilution, OH, 1H); 2.6±
3.3 (m, CH2CFCl, 2H); 3.8 (m, shifted to 4.7 ppm in the
presence of Cl3CNCO, CH2OH, 2H); 4.5 (complex system
3
CFClCH2, 2H), 3.72 (t, JHH6.4 Hz, CH2OH shifted to
4.6 ppm in the presence of Cl3CNCO, 2H).
1H-NMR (acetone d6) ꢀ: 1.85 (m, CH2CH2OH, 2H); 2.45
3
(m, CFClCH2, 2H); 3.65 (t, JHH6.0 Hz, CH2OH, 1 ppm
low ®eld shifted with Cl3CNCO, 2H); 2.30 (broad signal,
shifted with dilution, OH, 1H).
19F-NMR (CDCl3) ꢀ: 67.4 (AB part of an ABX system);
120.6 (ddt, 3JFcFa9.4 Hz, 3JFcFb9.7 Hz, 3JFcH6.6 Hz,
CFCl).
19F-NMR (acetone d6) ꢀ: 64.2 (AB part, same coupling
constants as above); 117.2 (same coupling constants as
above).
3
and qi, JHH6.2 Hz, CHI, 1H).
19F-NMR (CDCl3, with irradiation of CH2 of CFClCH2
19F-NMR (CDCl3) ꢀ: 67.9 (AB part of ABX system; Fa
group) ꢀ: 67.3 (AB system, JFaFb169.3 Hz, JFaFc
2
3
2
3
3
at 67.5, JFaFb169.3 Hz, JFaFc9.2 Hz; Fb at 68.2,
3JFbFc9.7 Hz, ClCF2);
3JFcFb9.7 Hz, CFCl).
120.7 (dd, JFcFa9.4 Hz,
2JFbFa169.3 Hz, JFbFc4.1 Hz, ClCF2, 2F); X part at
3
3
3
3
118.65 (dq, JFcHa35.7 Hz, JFcHb JFcFa9.1 Hz)
13C NMR (CDCl3) ꢀ: 25.6 (s, CH2CH2OH); 33.0
3
2
and 121.25 (m, JFcFa9.7); CFCl, 1F.
(d, JCF21.4 Hz, CFClCH2); 61.0 (s, CH2OH); 111.3
19F-NMR (CDCl3, irradiation of the protons of CHaHb
adjacent to CFCl group) ꢀ: 67.9 (as above); 118.65(t,
(dt, JCF255.5 Hz, JCF31.5 Hz,CFCl); 125.8 (td,
1
2
1JCF298.8 Hz, JCF33.4 Hz, ClCF2).
2
3JFcFa9.1 Hz) and 121.25 (t, JFcFa9.7 Hz).
3
13C-NMR (CDCl3) ꢀ: 22.3 (s, CHI); 42.2 (t, JCF
2.4. Dechlorination of A,1
2
1
22.1 Hz, CFClCH2); 68.3 (s, CH2OH); 110.3 (dt, JCF
0
258.9 Hz, 2JCF31.8 Hz, 2JCF 31.6 Hz, CFCl); 125.1 (td,
In a three necked round bottom ¯ask swept by an argon
¯ow and equipped with a condenser was introduced via a
septum 100 ml of dry DMF. Under vigourous stirring, 46.8 g
(0.72 mol) of zinc activated by 5 cm3 of acetic acid and
5 cm3 of acetic anhydride were placed in the ¯ask and then
the slurry was heated up to 908C. 50.0 g (0.237 mol) of
halogenated alcohol A,1 was then added dropwise and the
temperature was maintained at 908C. For 4 h after complete
addition the reaction was monitored by GC, the respective
retention time for the tri¯uorovinyl and chlorinated alcohols
being, 2.75 and 5.04 min. After cooling, the excess of zinc
was ®ltered off and the gross was treated with HCl 10% and
the ¯uorinated part extracted with diethyl ether. After
1JCF299.1 Hz, JCF32.9 Hz).
2
2.2.2. Reaction performed in Carius tube
A Carius tube saturated with nitrogen was ®lled with
40.0 g (0.14 mol) of Cl(C2F3Cl)I, 17.1 g (0.28 mol) of allyl
alcohol and 0.92 g (0.014 mol) of powdered copper. The
tube was degassed by 5 thaw-freeze cycles and then sealed.
It was placed in a shaking oven and heated at 1208C for 7 h.
After reaction and cooling to room temperature, the tube
was frozen in liquid nitrogen and then opened. After the
gross warmed up to room temperature, it was diluted in
diethyl ether and the copper was ®ltered off.