166
D.D. Moldavskii et al. / Journal of Fluorine Chemistry 94 (1999) 157±167
per¯uoroole®ns with alcohols [8], sym-di¯uorodiethyl ether
was obtained directly in the reactor from formaldehyde and
hydrogen ¯uoride and used as a solution [21]. Monohydro
and dihydro derivatives of per¯uorodibutyl ether, per¯uor-
otriethyl-, per¯uoro-tripropyl-, per¯uorotributyl-, and per-
¯uorotripentylamines were isolated by recti®cation from the
products of electrochemical ¯uorination of corresponding
hydrocarbon derivatives. Trimer hexa¯uoropropylene was
prepared by the reaction of per¯uoro-2-methylpent-2-ene
with P(NEt2)3 [22]. Fluorinations with elemental ¯uorine
were carried out in both ``open'' (using ca. 1:9 (v/v) F2±N2
blends) and ``closed'' (neat F2, at <20 mm Hg pressure)
systems using a steel reactor, as described previously except
that no cold traps were placed in the exit line. During
¯uorination experiments, careful control of the rate of
uptake of ¯uorine (and hence reaction temperature) is
essential to prevent the onset of potentially ``runaway''
free-radical mechanisms.
second reactor passed through a valve to a column ®lled
with Ca(OH)2 and then to a cooled receiver. In the case of
liquid-phase ¯uorination, solvent was condensed at the end
reactor 1.
4.4. Fluorination of polyfluorinated compounds C5±C12
The ¯uorination was performed in two 0.25 l reactors
made of 12X18HIOT steel, one with jacket for controlled
cooling, another with controlled heating. Each reactor was
equipped with a magnetic stirrer, re¯ux condenser, bubbler
for ¯uorine inlet and outlet for gaseous sampling. To the ®rst
reactor was passed the ¯uorinated compound and solvent,
and on achieving the required temperature, while stirring,
¯uorine began to pass through the bubbler at a given ¯ow
rate. When ¯uorine consumption ceased (¯uorine passed
through) the reaction mixture was transferred by pressure to
the second reactor, and ¯uorine passage was continued
while heating the mixture. After completing the ¯uorine
pass, the reaction mixture was washed with water and dried
over silica gel. Gas-phase catalytic ¯uorination has been
described earlier [18].
4.2. General procedure of fluorination of partially
fluorinated compounds (``adiabatic fluorination'')
Fluorination was performed in a 0.2 l reactor made of
12X18HIOT steel, equipped with valves for input of the
substrate, ¯uorine inlet and sample take off, with pressure
gauge, magnetic stirrer, jacket for cooling and heating, and
thermocouple sleeve. The reactor was kept in a steel pro-
tecting box. In the reactor was placed the reactant
(0.01 mol), solvent (when required, 120±150 ml) and after
attaining the required temperature, ¯uorine was added with
stirring, at a rate low enough to prevent heating the mixture
by more than 1.58C and non-consumed ¯uorine accumula-
tion to a pressure 0.02 MPa. When the ¯uorine consumption
®nished, the reactor was heated at 10±208C/h to complete
the reaction (the excess ¯uorine not disappearing for 6 h, as
tested with KI paper).
4.5. Sorbtion purification
A column made of 12X18HIOT steel 25 mm diameter
and 500 mm height was ®lled with activated carbon (BAU-2
or SKT). The studied liquid was admitted to the column
head, sampling rate was controlled by the bottom valve.
The eluent was collected in a receiver and analyzed
(Table 12).
References
[1] R.E. Banks (Ed.), Preparations, Properties and Industrial Application
of Organofluorine Compounds, Wiley, Chichester, 1982.
[2] N. Ishikawa (Ed.), Fluorine Compounds. Modern Technology and
Application, Mir, Moscow, 1984. p. 592.
4.3. Gas-phase fluorination
[3] G.G. Furin, G.P. Cambaretto, Direct Fluorination of Organic
Compounds, CLEUP, Padova, 1996, p. 40.
Fluorination of hexa¯uoropropene and deca¯uoropen-
tene was performed in two consecutive reactors made of
12X18HIOT steel, constructed as vertical tubes of 300 mm
length and 30 mm diameter, having jackets for controlled
cooling. The bottom sections were equipped with inlets for
¯uorine and ole®n, 20 mm from each other. The head
sections had sampling valves. The reaction mixture from
the ®rst reactor was passed through a cooled pipe to the
bottom of the second reactor, to which ¯uorine admission
was also provided. The system was equipped with a pressure
gauge and provided working up to 0.1 MPa. To the ®rst
reactor, cooled to a certain temperature, the ¯uorine and
ole®n ¯ows were introduced at controlled rates, with ¯uor-
ine to ole®n ratio 0.3±0.5:1. The reaction mixture from the
®rst reactor was passed to the second, cooled to a given
temperature, and ¯uorine was also admitted, in a 0.55±
0.75:1 ratio. The reaction products from the head of the
[4] W.A. Sheppard, C.M. Sharts, Organic Fluorine Chemistry, Benjamin,
New York, 1969.
[5] R.J. Lagow, J.L. Margrave, in: S.J. Lippard (Ed.), Progress in
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[9] D.D. Moldavsky, G.G. Furin, Zh. Obshch. Khim. 66 (1996) 1995.
[10] T.A. Bispen, D.D. Moldavsky, G.G. Furin, Zh. Prikl. Khim, 171
(1977).
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Shkultezkay, Zh. Prikl. Khim. 69 (1996) 112.
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(1994) 1844.
[13] T. Ono, K. Yamanouchi, K.V. Scherer, J. Fluorine Chem. 73 (1995)
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