STEPANOV et al.
1294
registered on a spectrometer Bruker WP-200 [operating
frequencies 200 (1H) and 188.3 (19F) MHz] with respect
to external references: trifluoroacetic acid and tetrameth-
ylsilane, and also by GC-MS method on an instrument
VGMS70-70E, ionizing electrons energy 70 eV, and by
GLC (columns 5 m Porapack Q and 3 m S301 on Chro-
mosorb W) comparing with authentic samples.
through the reactor at 280°C over 25 h. We obtained
37.4 g of a mixture of cyclic reaction products.
Substitution of chlorine by hydrogen in 2,3-dichlo-
rohexafluorobut-2-ene. a. 3.5 g of 2,3-dichlorohexaflu-
orobut-2-ene (E/Z 30:1) in a hydrogen flow was passed
through the reactor at 200°C over 2 h. We obtained
2.9 g of a mixture containing 79% of initial butene I
(E/Z 30 : 1), 11% of 2,3-dihydrohexafluorobut-2-ene (II)
(E/Z 1 : 11), and 10% of 2-hydro-3-chlorohexafluorobu-
tene (III) (Z-isomer).
Acommercial nickel-chromium catalyst according to
State Standard OST 113-03-4001-90 was crushed to the
size of diameter 1–2 mm.
The reactor was a quartz pipe of the diameter 14 mm,
working zone filled with catalyst 150 mm. Through the
working zone fluorochlorocarbon and hydrogen were
passed. The preliminary treatment of the catalyst con-
sisted in gradual heating (~50 deg/h) in a hydrogen flow
up to 300°C and keeping at this temperture till the end
of water liberation. Fluorochlorocarbons were charged
into the reactor in the amount of 1–4 g/h, molar ratio
fluorochlorocarbon : hydrogen 1:3. The temperature of
the reaction zone was 150–270°C. The catalyst between
the runs was not regenerated, and the residues of the fluo-
rinated compounds were removed from the reactor by the
hydrogen flow within 2–3 h at the working temperature.
The reaction products were collected in a trap cooled by
dry ice and analyzed.
b. 5.8 g of 2,3-dichlorohexafluorobutene (I) (E/Z 30 : 1)
in a hydrogen flow was passed through the reactor at
240°C over 4 h. We obtained 3.8 г of a mixture contain-
ing the initial butene I (26%, E/Z 1 : 5) and reduction
products: butene II (E/Z 3:2), butene III (Z-isomer), and
1,2-bis(trifluoromethyl)ethane in the ratio 1 : 3.3 : 0.7. The
overall yield of 2,3-dihydroperfluorobutene accounting
for the conversion was 57%.
Substitution of chlorine by hydrogen in 3,4-dichlo-
rodecafluorohex-3-ene. 9.7 g of 3,4-dichlorodecafluo-
rohex-3-ene in a hydrogen flow was passed through the
reactor at 240°C over 6 h. The mixture of products col-
lected in the trap (5.1 g) was subjected to rectification to
isolate 3.9 g of 3H,4H-decafluorohex-3-ene, bp 65–75°C,
E/Z 1 : 6.
Dechlorination of CF2ClCCl3. 5 g of CF2ClCCl3
in a hydrogen flow was passed through the reactor at
150°C over 2 h. Yield of 1,1-difluorodichloroethylene
3.1 g (90%).
Substitution of chlorine by hydrogen in 2,3-dichlo-
rodecafluorohex-2-ene. 2.9 g of 2,3-dichlorodecafluo-
rohex-2-ene in a hydrogen flow was passed through the
reactor at 240°C over 3 h. We obtained 1 g of (Z)-2H,3H-
decafluorohex-2-ene containing according to GLC 10%
of unidentified impurities.
Dechlorination of 1,2-dichlorohexafluorocyclobu-
tane. 3 g of 1,2-dichlorohexafluorocyclobutane in a hy-
drogen flow was passed through the reactor at 180°C over
1 h. We obtained 2 g of a mixture containing the initial
compound and perfluorocyclobutene in the molar ratio
3:2. Conversion 53%, yield of perfluorocyclobutene 57%,
at higher temperature the yield decreased.
Dimerization of CF3CCl3. 5.5 g of CF3CCl3 in a hy-
drogen flow was passed through the reactor at 210°C over
1.5 h. We isolated 3.4 g of a mixture containing the initial
CF3CCl3 (51%), 2,3-dichlorohexafluorobut-2-ene (39%),
E/Z 3:2, CF3CCl2H (9%), and CF2=CCl2 (1%). Yield of
2,3-dichlorohexafluorobut-2-ene 62% (accounting for
the conversion, 71%).
Substitution of chlorine by hydrogen in 1,2-di-
chlorotetrafluorocyclobutene. a. 4.7 g of 1,2-dichloro-
tetrafluorocyclobutenea in a hydrogen flow was passed
through the reactor at 200°C over 2 h. We obtained 2.5 g
of a mixture of reaction products.
Dimerization of CF3CF2CCl3. 36 g of CF3CF2Cl3 in
a hydrogen flow was passed through the reactor at 200°C
over 10.5 h. We obtained 27 g of a mixture containing
the initial CF3CF2CCl3 (42%), CF3CF=CCl2 (11%) and
3,4-dichloroperfluorohex-3-ene (47%). By the double
distillation we isolated 10 g of pure 3,4-dichlorodecaflu-
orohex-3-ene (E/Z 1:5.5), bp 101–103°C.Accounting for
the conversion the yield was 50%.
b. Analogously from 3 g of 1,2-dichloroperfluorocy-
clobutene at 250°C was obtained 0.9 g of the mixture of
reaction products.
Substitution of chlorine by hydrogen in 1,2-di-
chlorohexafluoro cyclopentene. 50.5 g of 1,2-dichloro-
hexafluorocyclopentene in a hydrogen flow was passed
Cross-dimerization of CF3CCl3 and CF3CF2CCl3.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 9 2010