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Reactions involving fluoride ion. Part 21 [1]. Nucleophilic substitution reactions of perfluorocyclobutene oligomers
JournalofHuorine Chemistry, 16 (1980) 161L181 0 Elsevier Sequoia S.A., Lausanne ~- Printed in the Netherlands
161
February 7,198O
Received:
REACTIONS
INVOLVING
SUBSTITUTION
RICHARD
REACTIONS
D. CHAMBERS,
Department South
Durham,
and RICHARD
PART
21
[l].
GRAHAM
DHl
NUCLEOPHILIC OLIGOMERS
TAYLOR
University 3LE
Science
Laboratories,
(Gt. Britain)
L. POWELL
Ltd.,
Cheshire,
ION.
OF PERFLUOROCYCLOBUTENE
of Chemistry,
Road,
I.C.I.
FLUORIDE
Mond
WA7
Division,
4QD
P.O. Box No.
8, The Heath,
Runcorn,
(Gt. Britain)
SUMMARY
Reaction with
some
displacement overall
of addition
of an allylic
the reaction
fluorine,
analogues in these
RESULTS
(1) and
oligomers,
gives
products
is used
here
fluorine
greater
and
to imply
substitution
than
SN2'
the
of
The reactivity
processes.
(2), is much
from
to an alkene
and is not meant
and this can be attributed
(4),
-
to describe
or vinylic
of both
(1)
arising
of a nucleophile
is concerted]
or a mixture
the dimers,
of
that of acyclic
to the ring
strain
present
compounds.
AND DISCUSSION
A range ion
nucleophiles
[N.B. this term
process
elimination that
of perfluorocyclobutene
simple
of compounds,
[2,3] or pyridine
Whilst
fluorocyclobutene.
(1) -
(41, can be obtained
[3-51 induced there
exists
on the reactions
of compounds
vinylic
[6], the chemistry
fluorine
(R~)~C=C(R~)~ cycloalkyl
which,
[Rf = perfluoroalkyl
group],
e.g.
oligomerisation
(2) and
a considerable
like
(1) and
of compounds or is part
(41, is much
by fluoride
of perliterature
(3), contain of the type
of a perflUOroless developed,
162 although
several
nucleophiles
of this type have been
recently
reported
In this paper
1121.
(1) -
(4) with
some
prepared
some fascinating
perfluoro-3,4-dimethylhex-3-ene
of one example,
compounds
alkenes
We have
[2,7-111.
we describe
simple
reactions
(5), with reactions
of
nucleophiles.
(4)
CF3 \c=c' / \ C2F5 CF3
C2F5
(5) The presence are attached
of F in a ring means to fluorine.
Formally the very
great
dimer ring
that
all unmarked
(2) is related
to compound
strain
in
present
(5).
positions
However,
(2) leads
to a much towards nucleophiles. Thus, in contrast (2) reacts rapidly with neutral alcohols
to reactivity compound (5), dimer (6) and, with ethanol, gives initially the monoethoxy derivative which reacts further to give the diethoxy compound (7). With occurs to give compound (8). ethoxide ion, tetrasubstitution enhanced
12)
EoH,
(5&o
/$+&
EtOH__
(7) (65%)
OEt
163 OEt
(OEt)
2
(8) The
initial
step
displacement occurs
in all nucleophilic
of fluorine,
by vinylic
the nucleophile product
e.g.
(2) +
substitution,
e.g.
and reaction
can then undergo
substitution
presence anion
Depending
(6) -+ (7).
then on
the disubstituted
reaction
with
(6) dissolves
ion to give
quenching
(9);
compound
(2) is SN2' reaction
overall
fluorines.
compound
of fluoride
of
(6), further
conditions,
further
of two allylic
Interestingly,
reactions
of this
in D.M.F.
a solution
solution
believed
with
in the to contain
bromine
yields
(10).
The reaction and yields
with
excess
the hydroxy
water
parallels
ketone
that with
ethoxide
ion
(11). OH
(1)
or
aqueous acetone RT
(2)
F2
0 (11)
Under
the same conditions
an equivalent
of water
SN2' displacement forward compounds
addition
dimer
to give to give
(12) and
compound (2)
the alcohol (13).
(5) is unreactive.
With the expected
not only undergoes
With
(13) are hydrolysed
(12), but also aqueous
acetone
further
to
straightboth
(11).
164
(2)
+
H20
1:l
/ination
\ddition
(13)
(12) (24%) Reaction
of
(2) with
(14) corresponding product
was
of a base
ethylene
to the diethoxy
obtained
with
glycol
gave
compound
compound
(46%)
a cyclic
(7).
(5) but only
product
A similar in the presence
[12].
(2)
+
HOCH2CH20H
1:l
(14) (60%) Dimer
(2) reacts
dimethylamine
are obtained ion,
to yield
(15) and
compound,
formed
vigorously
with during
a mixture
and very
of a mono-
(16) respectively. dimer
exothermically
and a di-substituted
The same two products
(1) and it seems probable
the reaction,
causes
some
HNMe2 *
(16)
(15) ca. 1:l HNMe2 (1)
*
(15)
+
(16)
ca. 4:l
that
fluoride
isomerisation
the dimers.
(2)
with
of
165 With compound failure
lithium (17).
chloride
Once
of alkene
reaction
again
this
(5) to react
occurs
to give
can be contrasted at all under
the dichloro with
the
the same conditions
[121.
(17)
Trimer
(4) is another
(Rf)2C=C(Rf)2 present
and,
in dimer
parallel
since
example
that of compound
ion
mixture
of an alkene
the ring
strain
(2), its reactivity
(4) is unaffected e&oxide
(77%)
(5).
by neutral
[4] to give
might
This
but reacts
the triethoxy
of the type less than
be expected
is, indeed,
ethanol
of SN2' displacement
is much
the case, rapidly
derivative
and vinylic
that
to i.e.
with
(lS), by a
substitution
of
fluorine. 0,Et (4)
OEt
EtO-/EtOH RT
+Il--JJ~ OEt (IS)
Trimer
(4) is unaffected
the presence which
reactions both
of sodium
has not yet been occur
cases
with
complex
be investigated. described Dimer containing nucleophile, its isomer mainly
by aqueous
carbonate
diethylamine
mixtures
sensitive
Similarly,
and sodium
are obtained novel
but reacts
borohydride
with
oil
vigorous
and these
reaction
in
but in
have yet to
fluoride
ion is
[131.
(1) is a member vinylic
acetone
to give a heat
characterised.
The highly
elsewhere
(66%)
fluorine
undergoes
and other,unidentified
known
and, depending
either
(2) it reacts
the monoether
of the well
mono-
rapidly
species.
of compounds of the
or tetra-substitution.
with
(19) together
class
on the nature
neutral
with
ethanol
an addition
Like
to yield
product
(20)
166
(19)
With whilst
ethoxide
with
(20)
ion, tetrasubstitution
water
compound
The reaction but with
(60%)
with
diethylamine
- see experimental)
occurs
(8%)
to qive
(8)
(11) is formed.
dimethylamine
has already
(using different simple
reaction
monosubstitution
NEt
been described, conditions
is the only process
2
(21) observed. With resulting
triethylamine,
from
loss of hydrogen
of the initially analogous formed
dimer
formed
reaction
with
(1) gave
fluoride This
adduct.
a complex
and then
perfluorocyclobutene
where
fiEt3 F(1)
NEt3 o"c
F
/
F
O-0
-74 -HF mixture
Et3N
NEt3 +
further
can be contrasted
[14].
ylide
mixture, reaction
with
an ylide
the is
167 Trimer
(3) also reacts
rapidly
than
the dimers,
vinylic
substitution
respectively.
neutral
ethanol,
and SR2' displacement
With
POOH
with
to give mono-ethers
methoxide
less (23) by
of fluorine
ion two products,
, c8F131Y0St
but
(22) and
(24) and
(25),
+c8F13,~/oE'
(3)
(22) (80%)
'gF13
(23) (10%)
= D-III
are obtained. displacement production
Compound and vinylic
of
(24) is formed substitution
(25) presumably
from an intermediate
involves
product.
As with
of SN2' whilst
loss of methyl the dimers,
OMe /
C8F13, (3)
by a mixture of fluorine,
fluoride
reaction
with
(OMe)2
'gF13 MeO-,
m RT
F
l
Me0
w
El F2 (24)
-MeF
4 'gF13
0
0
Me0
(25) water
parallels
that with
alkoxide
ion and gives
(26). (3)
aqueous
acetone RT
(26) (90%)
a high yield
of
168 With compound gives
borohydride
(27), whilst Vinylic
(28).
phenyl yield
sodium
lithium
with
trisubstitution diethylamine,
substitution
but the product
compound
occurs
vinylic
also occurs
reacts
to give
substitution
with
pentafluoro-
with
excess
reagent
gave
satisfactory
to
(29).
NaBH4 (3)
Tetraglyme
' H-F 2
2
(27) (79%)
NEt2
'gF13\ HNEt2 (3)
F
o"c
'
a (28)
'gF13
(73%)
'gF5
\ F /_1
(3) -3oOc Et20/hexane
Structural
All elemental from
Assignments
the products analyses.
I9 F n.m.r.
of CF2 groups is given
data.
described Product
The numbering
in products
below:-
above
identity
derived
usually system
followed
for n.m.r.
from the dimers,
simply assignments
(1) and
(2),
169
EXPERIMENTAL 19
Varian
F and 1H n.m.r.
spectra
were
recorded
at 40°C using
a
A56/60D
spectrometer, with CFC13 or TMS as external 19 Upfield F shifts are quoted as positive. G.1.c.
reference. was performed silicone
on a gas-density
gum
Molecular
weights
Reactions
of dimer
(a)
With
Dimer
were
dried
determined
(2) (1.2 q, 3.7 mmol) There
into water,
resultant
liquid
a single
compound
g.1.c.
was
30%
(Co1 'A').
on an AEI MS9masS
with
stirred
spectrometer.
vacuum
by q.1.c.
traces
layer
(5 ml)
The mixture removed,
to a cold trap.
The
and other,
separated
unidentified
by preparative
scale
as l-ethoxy-l-pentafluorocyclobutenyl-
hexafluorocyclobutane
(6) (nc) (1.0 q, 78%):
C, 34.6:
ethanol
(Co1 '0') to be essentially
of ethanol was
with
reaction.
fluorocarbon
under
component
and identified
was
an exothermic
the lower
was shown
The major
Analysis:
two columns;
ethanol
(P205) and transferred
species.
using
(2)
neutral
for two minutes. was poured
balance
(Co1 '0') or 20% di-isodecylphthalate
H, 1.6;
F, 59.4%;
Mf,
b.p.
131Oc;
350.
C10Fl10H5 requires: C, 34.29: H, 1.43; F, 59.71%; M, 350; Xmax 1711 -1 cm (C=C str); 15~ 98.9 (lF, triplet of triplets Jl = 16 Hz,
= 18 Hz; = CF-), 116.1 (2F, multiplet, 2-F), 121.1 (2F, J2 multiplet, l-F), 123.8 and 133.3 (4F, as AB, J = 228 Hz, 3-F) and 131.5
and 133.8
(CH3-, triplet
ppm
In an analogous stirred
with
mixture
was poured
reaction
ethanol
(5 ml)
liquid
complex
mixture.
component
separated
6H 1.40
J = 7 Hz).
(2) (1.4 q, 4.3 mmol)
the lower
shown
The three main
as disubstituted was
dimer
to a cold
(1.5 q) was
4-F);
(-CH2-, quartet,
was
for 18 h. at room temperature.
into water,
(P205) and transferred sultant
q.l.c.-m-s.
(2F, as AB, J = 223 Hz,
J = 7 Hz) and 3.97
layer removed,
trap under by g.1.c.
vacuum.
compounds,
The re-
(Co1 '0') to be a
components
by preparative
The
dried
were
identified
The major
C8F10(OEt)2. scale
q.1.c.
by
and identi-
fied as l-(1'- ethoxyhexafluorocyclobutyl)-2-ethmtrafluoro?cl@ butene
(7) (nc),
(1.0 q, 65%):
b.p.
192OC:
Analysis:
C, 38.4;
170 H, 2.5;
F, 50.3%;
M+,
F, 50.53%; H, 2.66; 111.2 (2F, multiplet, 123.9
and 133.3
376.
C12F1002H10
M, 376; 2-F),
Xmax
116.1
1685 cm-l
1.53
3.83
(CH3-, triplet
(-CH2-, quartet,
(b)
(20 ml) and
J = 7 Hz),
With
sodium
metal
was added
was
complete
was
slowly
reaction
under
was
to 90°C,
with
formation
left stirring
reduced
pressure'.
to dry ethanol
a mixture
added.
of dimers
There
of a white
(1)
was a
precipitate.
The
overnight
and the ethanol
removed
The residue
was distilled
in vacua
0.1 mm Hg) to give
by g.1.c.
J = 7 Hz)
ethoxide
reaction
mixture
J = 7 Hz),
J = 7 Hz).
(2) (2.6 g, 8.0 mmol)
vigorous
and 133.8
(CH3-, triplet,
(-CH2-, quartet,
(0.9 g, 39.1 mmol)
and when
AF
J = 4 Hz, l-F),
(4F, as AB, J = 224 Hz, 3-F) and 131.7 FH 1.40
Sodium
C, 38.30;
(C=C str);
(2F, triplet
(2F, as AB, J = 223 Hz, 4-F);
and 4.53
requires:
a colourless
(Co1 '0') to be a single
liquid
compound
(up
(2.3 g), shown
identified
as l-(1'-
ethoxyhexafluorocyclobutyl)-2,3,3-triethoxy-4,4-difluorocyclobutene
(8) (nc)
H, 5.0; H, 4.67; 112.7
(67%):
F, 35.0%; F, 35.51%;
3.96 and signal
4.42
(c)
solution various
was
Amax
C, 44.6;
re!yires:
1689 cm
122.8 and 133.1
quartets,
(6) with
J = 7 Hz, ratio
of compound
fluoride
CH3-
6H 3.90, 2:l:l)
and
resonances.
ion
(6) (0.76 g, 2.17 mmol), and DMF
SF
(4F, as AB, J = 219 Hz,
(5 ml) was
caesium
stirred
at room
for 30 minutes.
A small sample of the resultant and its 19 F n.m.r. spectrum recorded at
removed
temperatures.
These
indicated
the presence
(l'-ethoxyhexafluorocyclobutyl)-hexafluorocyclobutyl in solution:
6F 84.0
(very broad
anionic
centre
certain
integration).
bromine
(0.35 g, 2.19 mmol)
1 h.
C, 44.85:
(C=C str);
(2F, as AB, J = 219 Hz, 4-F):
(1.43 g, 9.4 mmol)
temperature
Analysis:
C16F804H20
at 1.5 due to overlapping
Compound
A mixture fluoride
l-F),
and 133.3
(all -CH2-'s,
centred
> 200°C;
428.
M, 428;
(2F, singlet,
3-F) and 130.5
b.p.
M+,
[151 and signals
The volatiles
singlet,
between
The residual
were
then
transferred
anion
-CF2-'S
was quenched
vacuum
to
(un-
at room temperature under
(9)
adjacent
119 and 138 ppm
solution
and stirred
of the l-
with for
to a cold
171 trap.
The
ferred
under
lower
(0.72 g) was identified
layer was removed,
vacuum shown
26.5:
dried
trap.
by g.1.c.
(10)
F, 51.5;
F, 50.78;
The resultant
Br,
(nc),
(79%):
Br, 17.1%.
17.82%;
signal,
b.p.
C10F120H5Br
adjacent
128.7
(2F, as AB, J = 221 Hz) and 131.2
With
(1) and
(20 ml) was
was removed
distilled liquid
adjacent
(69%):
125.7
115.3
(J = 1.5 Hz))
stirred
under
F, 51.1%;
1641 cm -1
at room
reduced
at 8.25.
125.9
reactions
a pale
(11)
requires:
yellow,
(nc),
F, 51.01%;
(C=C str. and C=O str.) and 132.5
(4F, as AB, J = 222
J = 20 Hz,
(11) decomposes
with
for 24 h.
and the residue
as l-hydroxy-2-(l'-hydroxy-
(2F, doublet,
Compound
and
temperature
pressure
C8F803H2
(broad)
l-F),
Hz, 3-F) and 131.6 ppm Similar
and
6H 1.63
and 4.20
(2) (3.0 g, 9.3 mmol)
(1.9 g) identified
(LF, singlet,
singlet
(4F,
126.0
(2F, singlet);
(ca. 60°C, 0.1 mm Hg) to give
Analysis:
1796 and
and 119.3
to >C(OEt)-),
hexafluorocyclobutyl)-4,4-difluorocyclobuten-3-one
xmax
C, 26.73:
6F 109.7
water
of dimers
acetone
viscous
Analysis:
J = 7 Hz).
excess
A mixture
The acetone
-CF2-'s
(J = 7 Hz) of doublets
(-CH2-, quartet,
molecular
compound
requires:
to ;CBr-),
complex
(CH3-, triplet
169OC;
no C=C str in I.R.;
(4F, as AB, J = 216, -CF2-'s
aqueous
liquid
(Co1 '0') to be a single
broad
(d)
(~205) and trans-
as l-ethoxy-l-(l'-bromohexafluorocyclobutyl)-hexa-
fluorocyclobutane
c,
to a cold
the separate
4-F):
on strong dimers
both
6H sharp heating. gave
(11) as
the only product.
(e)
With
and water
an equivalent
(94 ~1,
for 2 h. at room distillation
5.22 mmol) temperature
to leave
(Co1 '0') to consist were
of water
(2) (1.70 g, 5.25 mmol)
Dimer
separated
by preparative
liquid
g.1.c.
was
removed
components. to give
(10 ml) stirred
by
(2.06 g) shown
and two other scale
in ether
The mixture
and then the ether
a colourless of ether
was dissolved
was added.
by g.1.c These
l-(l'-hydroxy-
hexafluorocyclobutyl)-2,2,3,3,4,4-hexafluorocyclobutane
(13) (nc)
(0.59 g, 33%) and l-hydroxy-l-pentafluorocyclobutenyl-hexafluorocyclobutane and
(12)
(nc) (0.24 g, 14%).
24% respectively.
Yields
by g.1.c.
were
46
172 For
compound
H, 0.7;
(13):
F, 67.0%;
M, 342;
110 and 140 ppm
107OC;
I.R.
shows
(12):
highest
requires: no C=C
all unassigned;
For compound
Analysis:
M+, not observed,
(HF')., C8F120H2
i.e. M+-20 66.67%;
b.p.
b.p.
C, 28.1; peak
C, 28.07;
AF signals
str;
IS~, 3.7 lll°C;
at m/e = 322,
H, 0.58;
F,
between
(broad singlet).
Analysis:
C, 29.6:
H, 0.2;
H, 0.31; C8F110H requires: C, 29.81; M+, 322. F, 64.7%; 64.91%; 6F 99.9 (IF, M, 322; Amax 1721 cm (C=C str); triplet
(J = 15 Hz) of triplets
multiplet,
2-F),
121.5
(4F, as AB, J = 225 Hz, 3-F) Hz,
6H 4.25
4-F): When
stirred
(12) and
(f)
With
ml) was
added
5.65 mmol)
and ether solution
at room
rotary white
to give
in aqueous
(2F,
J = 12
both
compound
(11).
(2) (1.89 q, 5.83 mmol)
(20 ml) was
of ethylene
and the mixture
obtained.
This was
in ether
glycol
Vacuum
sublimation
rhombohedral
crystals
until
allowed removed
of the residue
was recrystallised
an to
on a
yielded
from Ccl4
identified
(10
(0.35 g,
stirred then
for 48 h and the ether
(1.21 g) which
large
116.3
and 134.8
(2F, doublet,
acetone,
to compound
to a mixture
temperature
evaporator. solid
127.5
qlycol
of dimer
homogeneous stand
and 132.6 ppm
hydrolysed
ethylene
slowly
l-F),
(broad resonance). overnight
(13) were
A solution
(J = 18 Hz), =CF-),
(2F, multiplet,
F,
a
at O°C
as bicycle-[5.2.-
01-2-spirohexafluorocyclobutyl-3,6-dioxa-8,8,9,9-tetrafluoronon1,7-ene
(14) (nc),
H, 1.1;
F, 55.3%;
H, 1.16;
(60%):
F, 54.91%;
CC14)
109.3
124.9
and 132.4
m.p.
M+ 346.
(2F, broad
54-55OC;
C10F1002H4
PI, 346;
x max
singlet,
Analysis: requires:
1688 cm-l
2-F),
121.4
C, 34.4; C, 34.68;
(C=C str) ; (2F, singlet,
(4F, as AB, J = 221 Hz, 3-F) and 131.2
AF (in l-F),
and 133.3
AH 4.80 (doublet J = 13 Hz, m?m (2F, as AB J = 224 Hz, 4-F); unassigned) and 4.80 (doublet of doublets Jl = 25 Hz and J2 = 3.5 Hz, unassigned).
(9) Dimer mmol)
were
With
dimethylamine
(2) (1.4 q, 4.3 mmol) transferred
under
and dimethylamine
vacuum
to a Carius
(1.4 q, 31.1
tube.
The tube
173 was
sealed
and allowed
reaction. opened
to warm;
and molecular
yellow
a mixture
there was
the tube had cooled
and the contents
removed pale
When
liquid
with water.
distilled
The
were
The monosubstituted
lower
by g.l.c.-m.s.
and a di-substituted
These
exothermic
temperature,
it was
layer was
(ca. 65OC, 0.1 mm Hg) to give
(1.4 g) shown
of a mono-
respectively).
shaken
a vigorous,
to room
separated
compound
(Co1 '0') to be
compound
(46 and 54%
by preparative
(a liquid)
a
was
scale
g.1.c.
identified
as
l-dimethylamino-2-heptafluorocyclobutyl-tetrafluorocyclobutene (15) (nc); Analysis: requires: str);
N, 4.1;
N, 4.01;
6F 104.4
F, 59.5%;
M+ 349.
F, 59.89%;
l-F),
125.7
134.0
(2F, as AB J = 228 Hz, 4-F) and 154.9
singlet,
and 132.8
Amax 1690 cm-1 (C=C 117.0 (2F, singlet,
M, 349; singlet, 2-F),
(2F, broad
(4F, as AB J = 228 Hz,
6H 3.31
;CF-);
The disubstituted
C10FllNH6
3-F), ppm
130.6
and
(lF, broad
(singlet).
compound
(a solid)
was
identified
as l-
dimethylamino-2-(l'-dimethylaminohexafluorocyclobuty~)-tetrafluorocyclobutene 51.3%;
M + 374.
50.80%;
(16) (nc); C12F10N2H12
M, 374;
triplet
Xmax
1683 cm-l
(J = 18) of triplets
l-F),
111.1
135.2
ppm
1:l each
Analysis:
and 124.9
C, 38.2:
requires:
2-F),
115.8
F,
(2F,
(2F, singlet,
(4F, as AB J = 222 Hz, 3-F) and 130.6
(2F, as AB J = 226 Hz,
4-F);
6H 2.72 and 3.13
and
(ratio
a singlet).
(h)
With
lithium
A mixture
chloride
of lithium
(2) (2.49 g, 7.69 mmol) temperature to a cold
for 3 h. trap.
The
washed
with water,
a cold
trap.
to be a single
chloride
and DMF
(1.22 g, 28.80 mmol),
(10 ml) was
The volatiles lower
dried
Analysis:
stirred
liquid
identified
was
shown
C, 26.7;
dimer
at room
transferred layer was
(P205) and transferred
The resultant compound
were
fluorocarbon
under
vacuum
removed,
under
by g.1.c.
vacuum
to
(Co1 '0')
as 1-chloro-2-(l'-chlorohexa-
fluorocyclobutyl)-tetrafluorocyclobutene 129Oc;
F,
H, 3.21;
cSF 103.4
(C=C str);
(J = 24),
H, 3.5:
C, 38.50;
F, 52.5;
(17) Cl,
(nc) (77%):
20.5%;
M+,
356
b.p. 35
(
A max
Cl).
M, 356); requires: C, 26.89; F, 53.22: Cl, 19.89%; -1 6F 114.1 (2F, multiplet, 2-F), 120.7 (C=C str); 1640 cm
C8F10C12
(2F, multiplet, (2F, singlet,
l-F), 4-F).
121.9
(4F, singlet,
3-F) and 129.6
ppm
174 Reactions
of trimer
(a)
With
Trimer two layers
neutral
(4) was
With
Sodium and when
was
added
sodium
for several
days with
ethanol.
and after
two weeks
g.1.c.
was
removed
in vacua
complete, stirred
under
in either
was
added
trimer
overnight
reduced
from methanol
C18F1503H15 A max
requires:
at 1.6, -CH2-'S
trimer
(15 ml)
(66%) 564.
Mi
M, 564;
F, 50.53%;
(2F, multiplet,
(lF, broad
multiplet,
)CF-)
(12F, unassigned);
6H
(CC14)
at 4.2.
(4) in aqueous
and water
The mixture
acidified
(dil. HCl). (50 ml).
on a rotary
evaporator
spectrum
to separate
with
reaction.
further.
of sodium
was
left stirring
The
lower
carbonate
with
overnight
addition
the lower
and then and dissolved
layer.
(2 x 50
The
(MgS04) and the ether
a yellow
unsuccessful
of
(3.4 g),
extracted
liquid
this to be a mixture.
were
temperature
in an exothermic
layer was removed
dried
to leave
at room
However,
layer was ether
combined water,
indicated
components
acetone
(5 ml) resulted
The upper
and the extracts
was then washed
pursued
and
F, 50.4%;
H, 2.66;
122 and 136 ppm
(3.4 g) to a mixture
reaction.
n.m.r.
(2.0 g)
(18) (nc),
(Ccl,) 107.9
lead to any detectable
in ether
a solid
With water
the trimer acetone
temperature.
and the residue
(low temperature)
H, 2.7;
176.4
ring),
between
Stirring did not
6F
(C=C str);
centred
(c)
C, 38.4: C, 38.30;
in unsaturated
and signals
ml)
Analysis:
1681 cm-l
CH3-'S
(20
as 1,3-djethoxy-2-(l'-ethoxyhexafluorocvclobutyl)-3-
52-53OC;
-CF2-
to ethanol
at room
pressure
heptafluorocyclobutyl-4,4-difluorocyclobutene m.p.
layer.
(4) (2.6 g, 5.4 mmol)
(cd. 60°C, 0.1 mm Hg) to give
was recrystallised
identified
The (Co1 '0')
ethoxide
reaction
was
of any products
(0.65 g, 28.3 mmol)
and the mixture
The ethanol
which
stirred
the presence
metal
ml)
sublimed
ethanol
did not homogenise
did not indicate
(b)
(4)
solution removed
(2.0 g).
A l9F
Various
attempts
and the reaction
was not
1 75
(d)
With
Trimer amine
diethylamine
(4) (3.3 g, 6.8 mmol)
(10 ml) with
vigorous
reaction
hydrofluoride. washed
stirring occurred
gave
n.m.r.
Molecular
a pale yellow
and g.1.c.
separate
(e)
sodium
To a suspension tetraglyme
(20 ml) with
the mixture carefully
dried
was
was
distilled shown
attempts
and so the reaction
to
was
trimer
the addition
were
bulked,
removed
complete
extracted
washed
with
(3 x
water, to leave
a
(Co1 '0') to be a
components.
after
amount
was
by distillation
by g.1.c.
in
(4) (3.3 g,
for 1 h. and then
(100 ml) and ether
the addition
for 1 h. on a steam
a small
(1.0 g, 25.6 mmol)
slowly
bath
was
and then
of a colourless
(Co1 '0') to be a highly
complex
and the complexity
complete,
the
flash
liquid
which
mixture.
of the product,
was
In the
was not pursued.
(a)
of dimer
With
A mixture stirred
into water
was
reaction,
of the low recovery
ferred
by l?F
shown
Various
temperature
and ca. 20 other
to give
Reactions
was
When
(3.1 g) shown
stirred
by g.1.c.
reaction
and the filtrate
This was
mixture.
added
at room
extracts
liquid
of ether
mixture
of diethylamine-
(0.1 mm Hg, up to
g).
borohydride
was
stirring.
into water
In a similar
view
of sodium
stirred
The ether
mixture
A
borohydride
(MgS04) and the ether
colourless
(1.7
unsuccessful
at -18OC
rapid
poured
50 ml).
distillation
to diethyl-
(ice-bath).
further.
With
6.8 mmol)
added
cooling
by filtration
liquid
were
slowly
precipitation
to be a complex
components
not pursued
with
This was removed
with water.
90°C)
was
and external
neutral
ethanol
of dimer
at room
(1) (1.1 g, 3.4 mmol)
temperature
and the lower
under
shown
(1)
vacuum
layer
to a cold
by g.l.c.-m.s.
substituted
compounds,
compounds.
The major
for 18 h. removed, trap.
and ethanol
The mixture
dried
The resultant
product
monosubstituted
was poured
(P205) and trans-
(Co1 '0') to be a mixture an addition
(5 ml)
liquid
(1.0 g)
of two mono-
and two disubstituted
compound
(0.61 g, 60%) was
176 separated
by preparative
scale
g.1.c.
and identified
2-heptafluorocyclobutyl-tetrafluorocyclobutene separated
was
which
identified
was
the addition
product
as l-ethoxy-
(19) (nc).
Also
(< 0.1 g, ca. 8% by g.1.c.)
as 1-ethoxy-2-hydro-2-heptafluorocvclobutyl-
pentafluorocyclobutane
(20) (nc) .
Other
components
were
not
characterised. For compound 1.0;
F, 59.5%:
1.43;
(19): M+,
F, 59.71%;
(2F, multiplet,
b.p.
350.
Xmax
116.3 3-F),
(lF, singlet,
J = 7 Hz) and 4.48
C10F120H6
requires:
C=C
6F 195.5
str;
113.6
(20); ,C,
3.48
was
stirred
above
(b)
(15)
(c) Dimer
was
(CH3-,
J = 7 Hz). H, 1.4%;
M, 370;
>CF-)
and signals
4.28
M+,
370.
I.R. shows
6H 1.62
a mixture
no
between
(CH3;
triplet
(-CH2-, quartet,
of dimer
The reaction
liquid
shown
J = 7
(1) and ethanol
mixture
by q.1.c.
as for g.
was
treated
as
to be a mixture was
identified
as
stirring
dimer
gave
(16)
removed
(1) (1.7 g, 5.2 mmol)
a mixture
(1.5 g) of
(17%).
liquid
added
cooling
the mixture
and molecular
a colourless
was
and external
complete,
identified
Thus
diethylamine
(1) (1.4 q, 4,3 mmol)
was
layer
was
(0.9 g, 20.0 mmol)
(83%) and compound
With
(5 ml) with
lower
(2F, as AB J = 229
1Jith dimethylamine
and dimethylamine
to give
1.62%;
127.2
AH 1.50
C, 32.4;
(J = 1 Hz)),
for 3 minutes.
The procedure
addition
and 133.8
components, the major one of which 19 (19) by F n.m.r. spectroscopy.
compound
compound
l-F),
,)F-);
(-CH2-, quartet,
32.43;
6F 111.2
and 134.4
Analysis:
reaction
and the resultant
of several
H,
(C=C str);
, very broad).
(-CH(
In a similar
requ_if_-es: C, 34.29;
(llF, unassigned);
(J = 7 Hz) of doublets Hz) and
130.8
(lF, multiplet,
and 138.5 ppm
H,
(2F, multiplet,
Hz, 4-F) and 179.4 ppm For compound
C, 34.1;
1695 cm
(4F, as AB J = 229 Hz,
triplet
Analysis:
C10F110H5
M, 350;
2-F),
154OC;
was
slowly
shaken
distilled
(1.2 q) which
to diethylamine
(ice-bath). with
When
water
the
and the
(ca. 85OC, 0.1 mm Hq) rapidly
darkened.
This
as 1-diethylamino-2-heptafluorocyclobutyltetra-
fluorocyclobutene
(21) (nc),
(74%);
Analysis:
F, 55.0%;
M+ 377.
177 C12F11NH10 requires: str);
6F 104.2
125.9
and 132.0
F, 55.44%;
M, 377;
(2F, multiplet,
2-F),
~max
(4F, as AB J = 226 HZ, 3-F),
(2F, as AB J = 228 Hz, 4-F) and 159.2 ppm IS~ 1.42
1676 cm-l (C=C (2F, multiplet, I-F),
116.0
(CH3-, triplet,
130.1
and 133.6
(lF, singlet,
J = 7 Hz) and 3.55
:CF-);
(-CH2-, quartet,
J =
7 HZ).
(d)
With
Dimer and cooled
at -18OC
10.40 mmol) was
trimethylamine
(1) (1.42 g, 4.38 mmol) whilst
in ether
filtered
under
(10 ml) was
nitrogen
shown
to be a quarternary
water
and resultant
to fluoride
was dissolved
a solution added
to give ammonium
a white salt
attempts
the reaction
with
to separate
evaporator
and the resultant
to be a complex
components
neutral
were
mixture.
unsuccessful
and
ethanol
(3) (2.0 g, 4.1 mmol)
and the lower
layer
under
vacuum
q) was
shown
by g.l.c.-m.s.
trimer
(3), two monosubstituted
8:l and traces were
was
temperature.
ferred
products
in
(3)
for 8 h. at room
into water
soluble
was not pursued.
Trimer ml)
(0.46 g),
solution shows only a resonance corresponding 19 F n.m.r. spectrum). The ether was
of trimer
(a)
solid
(extremely
ion in its
from the filtrate on a rotary 19 oil shown by F n.m.r. spectroscopy
Reactions
(5 ml)
(1.05 g,
The mixture
slowly.
removed
Various
in ether
of triethylamine
to a cold
removed, trap.
with
dried
ethanol
was
(P205) and trans-
The resultant
products
liquid
(1.8
of
(ca. 90%) in the ratio
product.
by preparative
(10
then poured
(Cal. '0') to be a mixture
of a disubstituted separated
stirred
The mixture
The monosubstituted
scale
g.1.c.
and identified
as l-ethoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl~tetrafluorocyclobutene
(22)
(nc) (major product),
and 4-ethoxy-
l-(l'-heptafluorocyclobutylhexafluorocyclobutyl~-tetrafluorocyclobutene
(231 (nc).
For compound 0.7; 0.98;
F, 62.7%; F, 63.09%;
(22): M+,
b.p.
512.
M, 512;
202OC;
C14F170H5 hmax
Analysis: requires:
1678 cm-l
C, 32.5:
H,
C, 32.81;
H,
(C=C str);
sF 174.2
178 >CF-)
(lF, singlet, unassigned):
dH 1.60
For compound observed,
peak
C, 32.81;
(CH3-, triplet,
(23);
Analysis:
at m/e = 483,
H, 0.98%;
With
Sodium (20 ml)
sodium
metal
and when
temperature,
pressure.
vacuum
ratio
(0.6 g, 26.1 mmol)
, not
requires:
)CF-)
6F
and signals (CH3-,
J = 7 Hz).
was dissolved
solution
The mixture
material
was
stirred
There
was
was
for 16 h. at
was removed
in the residue
to room
added.
under
reduced
transferred
trap
and the resultant
liquid
(Co1 'A') to consist
of two components
in the approximate
3:l
to a cold
was
the methanol
in methanol
had cooled
(3) (4.2 g, 8.6mmol)
and then
Volatile
+
(C=C str);
AH 1.53
(-CH2-, quartet,
M
methoxide
reaction.
temperature
C14F170H3
1710 cm-l
(lF, singlet;
the resultant
trimer
an exothermic
g.1.c.
(-CH2-,
H, 0.8%;
(15F, unassigned);
= 7 Hz) and 4.22
(b)
g.1.c.
(16F
J = 7 Hz) and 4.58
C, 32.7;
imax
174-5
112 and 134 ppm
triplet,J
under
108 and 133 ppm
i.e. IIf-29.
M, 512;
(lF, singlet: =CF-),
between
room
between
J = 7 Hz).
quartet,
98.0
and signals
(3.6 g).
to give
The
These
a liquid
liquid
were
separated
shown
by preparative
by
scale
and a solid.
(major product)
was
identified
as 1,3,3-tri-
methoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl)difluorocyclobutene 34.7:
H, 1.9;
34.48;
H, 1.72;
172.6
(24)
6F (14F, unassigned);
M+,
F, 54.60%;
(lF, singlet,
( lC(OCH3)2,
(nc):
F, 54.2%;
>CF-)
hH 3.75
b.p. 522.
> 210°C;
Analysis:
C15F1503Hg
14, 522;
Xmax
and signals (=C-0CH3,
1679 cm-l
between
singlet)
C,
requires:
C,
(C=C str);
111 and 133 ppm
and 4.30
singlet).
The solid
was
recrystallised
from Ccl4
and identified
as
l-methoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl)-4,4Analysis: difluorocyclobuten-3-one (25) (nc) m.p. 53-54OC; + M 476. C13H150H3 requi_rys: F, 59.87%; M, 476; -i A max 1815 cm (C=C str) and 1641 cm (C=O str); 6F (in CC14)
F, 59.7%; 178.6
(lF, pentet
133 ppm
J = 23 Hz, >CF-)
(14F, unassigned);
bH
and signals
(in CC14)
4.65.
between
111 and
179 A sample
of compound
for 8 days to give identified
(c)
A mixture
of its infrared
of trimer
(20 ml) was
acetone
was removed
sublimed
in vacua
;CF-)
c,
under
reduced
31.1;
and signals
in tetraglyme with
addition steam The
lower
sodium
layer
to give with
C12F15H3 xmax
unsaturated
at room
118 and
133 ppm
(e)
With
Procedure and diethylamine identified
the
for 1 h. on a
temperature
and the residue
overnight. flash
to be
The two fractions
C, 33.3;
were
(27) (nc)
H, 0.7;
H, 0.69;
SF, 109.6
(79%):
F, 65.6%: F, 65.97%;
(2F, singlet,
(lF, singlet
(12F, unassigned):
J = 3 Hz) and 6.59
When
as l-(l'-heptafluorocyclobutylhexa-
c, 33.33:
176.1
(3) (6.0 g, 12.3
cooling.
(1.1 g) shown by g.1.c.
layer.
(C=C str); ring),
J = 22 Hz,
(2.3 g, 53.7 mmol)
was heated
removed
a liquid
the lower
requtres:
181-183°C;
(14F, unassigned).
trimer
and external
the mixture
Analysis:
1608 cm
(4.8 g)
(C=C str) and
(lF, pentet
slowly
left stirring
and identified
164OC;
solid
m.p.
1804 cm
fluorocyclobutyl)-3,3-difluorocyclobutene b.p.
The
C12F;1502H requires:
borohydride
added
(3.1 g) was
identical
a white
(90%):
462.
Amax
of sodium
complete
and then
and aqueous
temperature.
borohydride
stirring
distilled
combined
that of
and the residue
115 and 137 ppm
(20 ml) was
was
(nc)
M+,
M, 462;
between
rapid
bath
(26)
rSF (H20) 178.2
To a suspension
mmol)
with
(26),
'-heptafluorohexafluorocyclobutyl)-
F, 62.0%;
F, 61.69%;
With
pressure
(90°C, 0.1 mm Hg) to give
(C=O str);
(d)
spectrum
for 24 h. at room
4,4-difluorocyclobuten-3-one
31.17; -1 1640 cm
derivative,
(3) (5.6 g, 11.5 mmol)
stirred
as l-hydroxy-2-(1
c,
hydroxy
water
acetone
Analysis:
to the atmosphere
sample.
With
identified
left open
the corresponding
by comparison
an authentic
(25) was
>CF-)
AH 3.35
M+,
M, 432; -CF2-
and signals (-CH2-,
432.
in between
triplet
(=CH-, singlet).
diethylamine was
Thus,
as for m.
(5 ml)
gave
trimer
a pale yellow
as l-diethylamino-2-
(3) (3.4 g, 7.0 liquid
product
(1 I-heptafluorocyclobutylhexa-
fluorocyclobutyl)-tetrafluorocyclobutene
(28) (nc)
(73%):
nUlI01)
(2.9 Cr)
180
Analysis:
F, 60.3%;
539;
Mf,
C16F17NH10
requires:
F, 59.93%;
8F 172.9 (lF, singlet, hmax 1662 cm-l (C=C str); M, 539; and signals between 103 and 133 p.p.m. (16F, unassigned); (CH3-, triplet
1.36
(f)
With
J = 7 Hz) and 3.34
pentafluorophenyl
Pentafluorobromobenzene a mixture
of ether
nitrogen,
to -3OOC.
21.5 mmol) between
was added
allowed
overnight. ether
to warm
Water
extracted
organic
molecular
being
to room
This was removed
distilled
then washed
(0.1 mm,
the same,
pure
compound.
and identified
Analysis:
36.83:
benzene C6F5
ring),
ring),
signals
C, 36.9:
F, 63.17%; 138.1
161.8
between
trimer
layer
combined
with water,
to give The
separated, with
dried
the
(MgS04)
The residue
a pale liquid
yellow was
compound,
was
liquid
shown
by
the solid
The solid was recrystallised
as perfluoro-1-parabiphenyl-2-cl'-
cyclobutylcyclobutyl)cyclobutene 108OC;
solution,
and left stirrinq
the aqueous
(2.41 g).
in
under
maintained
complete
evaporator.
80°C)
dissolved
and the resultant
and the extracts
on a rotary
solid
being
was
temperature
(Co1 '0') to be > 90% of a single
from ether
c,
slowly
(5'0ml) was added,
(1.17 g) and a white g.1.c.
the addition added
(2 x 20 ml)
layer.
and the ether
was
was
(13 ml of a 1.65M
the temperature
When
J = 7 Hz).
(12 ml) and cooled,
lithium
slowly,
(3) (3.70 g, 7.61 mmol) mixture
and hexane
n-Butyl
hH
lithium
(5.3 g, 21.5 mmol)
(18 ml)
-20 and -3OOC.
(-CH2-, quartet
>CF-)
(29) (nc) F, 62.8%;
M, 782; (2F, ortho
(2F, meta
6F
M+ 782.
ring),
m.p.
107-
requires: C24F26 (4F, di.substituted
(Et20) 136.4
F, C6F5 ring),
F, C6F5
109 and 128 ppm
(ca. 58%);
150.5
171.7
(lF, para
F,
(lF, \CF-) and
(16F, unassigned).
ACKNOWLEDGEMENTS
We thank (to G.T.) award.
the Science
and 1-C-I.
Ltd.,
Research
Council
Mond Division
for a C.A.S.E.
for co-operation
award in this
181 REFERENCES
1
Part H.C.
Fielding,
J.C.S.
2
R.D.
Chambers,
M-Y.
3
R.D. Chambers,
XX.
S. Bartlett,
R.D.
Chambers,
Perkin
Gribble
A.A.
Lindley
and
I, in the press. and E. Marper,
J.C.S.
Perkin
I
(1973) 1711. G. Taylor
and R-L.
Powell,
and H.A.
Smith,
J.C.S.
Perkin
I,
in press. 4
R.L.
5
-74 (1952) 1638. R.D. Chambers, G. Taylor
6
R.D. Chambers
Bahner,
C.T.
Bahner
J. Am. Chem.
and R.L. Powell,
J.C.S.
Sot.,
Chem.
Comm.
(1978) 433.
50;
and R.H. Mobbs,
R.D. Chambers
'Fluorine
Wiley-Interscience, 7
J. Riera
8
M.W.
9
J.A.
10
W.J.
and D.M.
Fluorine
in Organic
New York,
and R. Stephens,
Graystone
Adv.
1973
Chem, -4 (1965) Chemistrv',
and references
therein.
Tetrahedron,
Lemal,
-22 (1966) 2555. J. Am. Chem. Sot., -98 (1976)
1278. Oliver,
J. Fluorine
R. Stephens,
J.C.
Tatlow
and J.R.
-7 (1976) 555. and R.V. Lindsey, J. Am. Chem.
Taylor,
Chem.,
Middleton
Sot., -86
(19641,
4948. 11
H.H.
Evans,
J.C.S. 12
R.D.
R. Fields,
Perkin
R.N.
Haszeldine
Chambers,
J. Hutchinson
A.A.
Lindley,
P.D.
and G. Whittaker, G. Taylor
Philpot,
J.C.S.
and R.L.
R.D.
14
D.J.
15
sot., -99 (1977) 4830. For other examples see R.D. Chambers,
Chambers,
H.C.
Perkin
Powell,
13
(1979)
and M. Illinaworth,
I (1973) 649. Fielding,
I (1979) 214.
J.C.S.
Chem.
Comm.,
1062.
Burton,
R.D.
and R.L. Powell,
Howells
J.C.S.
and P. Van Der Valk,
Perkin
J. Am. Chem.
R.S. Matthews,
I, in the press.
G. Taylor
161
February 7,198O
Received:
REACTIONS
INVOLVING
SUBSTITUTION
RICHARD
REACTIONS
D. CHAMBERS,
Department South
Durham,
and RICHARD
PART
21
[l].
GRAHAM
DHl
NUCLEOPHILIC OLIGOMERS
TAYLOR
University 3LE
Science
Laboratories,
(Gt. Britain)
L. POWELL
Ltd.,
Cheshire,
ION.
OF PERFLUOROCYCLOBUTENE
of Chemistry,
Road,
I.C.I.
FLUORIDE
Mond
WA7
Division,
4QD
P.O. Box No.
8, The Heath,
Runcorn,
(Gt. Britain)
SUMMARY
Reaction with
some
displacement overall
of addition
of an allylic
the reaction
fluorine,
analogues in these
RESULTS
(1) and
oligomers,
gives
products
is used
here
fluorine
greater
and
to imply
substitution
than
SN2'
the
of
The reactivity
processes.
(2), is much
from
to an alkene
and is not meant
and this can be attributed
(4),
-
to describe
or vinylic
of both
(1)
arising
of a nucleophile
is concerted]
or a mixture
the dimers,
of
that of acyclic
to the ring
strain
present
compounds.
AND DISCUSSION
A range ion
nucleophiles
[N.B. this term
process
elimination that
of perfluorocyclobutene
simple
of compounds,
[2,3] or pyridine
Whilst
fluorocyclobutene.
(1) -
(41, can be obtained
[3-51 induced there
exists
on the reactions
of compounds
vinylic
[6], the chemistry
fluorine
(R~)~C=C(R~)~ cycloalkyl
which,
[Rf = perfluoroalkyl
group],
e.g.
oligomerisation
(2) and
a considerable
like
(1) and
of compounds or is part
(41, is much
by fluoride
of perliterature
(3), contain of the type
of a perflUOroless developed,
162 although
several
nucleophiles
of this type have been
recently
reported
In this paper
1121.
(1) -
(4) with
some
prepared
some fascinating
perfluoro-3,4-dimethylhex-3-ene
of one example,
compounds
alkenes
We have
[2,7-111.
we describe
simple
reactions
(5), with reactions
of
nucleophiles.
(4)
CF3 \c=c' / \ C2F5 CF3
C2F5
(5) The presence are attached
of F in a ring means to fluorine.
Formally the very
great
dimer ring
that
all unmarked
(2) is related
to compound
strain
in
present
(5).
positions
However,
(2) leads
to a much towards nucleophiles. Thus, in contrast (2) reacts rapidly with neutral alcohols
to reactivity compound (5), dimer (6) and, with ethanol, gives initially the monoethoxy derivative which reacts further to give the diethoxy compound (7). With occurs to give compound (8). ethoxide ion, tetrasubstitution enhanced
12)
EoH,
(5&o
/$+&
EtOH__
(7) (65%)
OEt
163 OEt
(OEt)
2
(8) The
initial
step
displacement occurs
in all nucleophilic
of fluorine,
by vinylic
the nucleophile product
e.g.
(2) +
substitution,
e.g.
and reaction
can then undergo
substitution
presence anion
Depending
(6) -+ (7).
then on
the disubstituted
reaction
with
(6) dissolves
ion to give
quenching
(9);
compound
(2) is SN2' reaction
overall
fluorines.
compound
of fluoride
of
(6), further
conditions,
further
of two allylic
Interestingly,
reactions
of this
in D.M.F.
a solution
solution
believed
with
in the to contain
bromine
yields
(10).
The reaction and yields
with
excess
the hydroxy
water
parallels
ketone
that with
ethoxide
ion
(11). OH
(1)
or
aqueous acetone RT
(2)
F2
0 (11)
Under
the same conditions
an equivalent
of water
SN2' displacement forward compounds
addition
dimer
to give to give
(12) and
compound (2)
the alcohol (13).
(5) is unreactive.
With the expected
not only undergoes
With
(13) are hydrolysed
(12), but also aqueous
acetone
further
to
straightboth
(11).
164
(2)
+
H20
1:l
/ination
\ddition
(13)
(12) (24%) Reaction
of
(2) with
(14) corresponding product
was
of a base
ethylene
to the diethoxy
obtained
with
glycol
gave
compound
compound
(46%)
a cyclic
(7).
(5) but only
product
A similar in the presence
[12].
(2)
+
HOCH2CH20H
1:l
(14) (60%) Dimer
(2) reacts
dimethylamine
are obtained ion,
to yield
(15) and
compound,
formed
vigorously
with during
a mixture
and very
of a mono-
(16) respectively. dimer
exothermically
and a di-substituted
The same two products
(1) and it seems probable
the reaction,
causes
some
HNMe2 *
(16)
(15) ca. 1:l HNMe2 (1)
*
(15)
+
(16)
ca. 4:l
that
fluoride
isomerisation
the dimers.
(2)
with
of
165 With compound failure
lithium (17).
chloride
Once
of alkene
reaction
again
this
(5) to react
occurs
to give
can be contrasted at all under
the dichloro with
the
the same conditions
[121.
(17)
Trimer
(4) is another
(Rf)2C=C(Rf)2 present
and,
in dimer
parallel
since
example
that of compound
ion
mixture
of an alkene
the ring
strain
(2), its reactivity
(4) is unaffected e&oxide
(77%)
(5).
by neutral
[4] to give
might
This
but reacts
the triethoxy
of the type less than
be expected
is, indeed,
ethanol
of SN2' displacement
is much
the case, rapidly
derivative
and vinylic
that
to i.e.
with
(lS), by a
substitution
of
fluorine. 0,Et (4)
OEt
EtO-/EtOH RT
+Il--JJ~ OEt (IS)
Trimer
(4) is unaffected
the presence which
reactions both
of sodium
has not yet been occur
cases
with
complex
be investigated. described Dimer containing nucleophile, its isomer mainly
by aqueous
carbonate
diethylamine
mixtures
sensitive
Similarly,
and sodium
are obtained novel
but reacts
borohydride
with
oil
vigorous
and these
reaction
in
but in
have yet to
fluoride
ion is
[131.
(1) is a member vinylic
acetone
to give a heat
characterised.
The highly
elsewhere
(66%)
fluorine
undergoes
and other,unidentified
known
and, depending
either
(2) it reacts
the monoether
of the well
mono-
rapidly
species.
of compounds of the
or tetra-substitution.
with
(19) together
class
on the nature
neutral
with
ethanol
an addition
Like
to yield
product
(20)
166
(19)
With whilst
ethoxide
with
(20)
ion, tetrasubstitution
water
compound
The reaction but with
(60%)
with
diethylamine
- see experimental)
occurs
(8%)
to qive
(8)
(11) is formed.
dimethylamine
has already
(using different simple
reaction
monosubstitution
NEt
been described, conditions
is the only process
2
(21) observed. With resulting
triethylamine,
from
loss of hydrogen
of the initially analogous formed
dimer
formed
reaction
with
(1) gave
fluoride This
adduct.
a complex
and then
perfluorocyclobutene
where
fiEt3 F(1)
NEt3 o"c
F
/
F
O-0
-74 -HF mixture
Et3N
NEt3 +
further
can be contrasted
[14].
ylide
mixture, reaction
with
an ylide
the is
167 Trimer
(3) also reacts
rapidly
than
the dimers,
vinylic
substitution
respectively.
neutral
ethanol,
and SR2' displacement
With
POOH
with
to give mono-ethers
methoxide
less (23) by
of fluorine
ion two products,
, c8F131Y0St
but
(22) and
(24) and
(25),
+c8F13,~/oE'
(3)
(22) (80%)
'gF13
(23) (10%)
= D-III
are obtained. displacement production
Compound and vinylic
of
(24) is formed substitution
(25) presumably
from an intermediate
involves
product.
As with
of SN2' whilst
loss of methyl the dimers,
OMe /
C8F13, (3)
by a mixture of fluorine,
fluoride
reaction
with
(OMe)2
'gF13 MeO-,
m RT
F
l
Me0
w
El F2 (24)
-MeF
4 'gF13
0
0
Me0
(25) water
parallels
that with
alkoxide
ion and gives
(26). (3)
aqueous
acetone RT
(26) (90%)
a high yield
of
168 With compound gives
borohydride
(27), whilst Vinylic
(28).
phenyl yield
sodium
lithium
with
trisubstitution diethylamine,
substitution
but the product
compound
occurs
vinylic
also occurs
reacts
to give
substitution
with
pentafluoro-
with
excess
reagent
gave
satisfactory
to
(29).
NaBH4 (3)
Tetraglyme
' H-F 2
2
(27) (79%)
NEt2
'gF13\ HNEt2 (3)
F
o"c
'
a (28)
'gF13
(73%)
'gF5
\ F /_1
(3) -3oOc Et20/hexane
Structural
All elemental from
Assignments
the products analyses.
I9 F n.m.r.
of CF2 groups is given
data.
described Product
The numbering
in products
below:-
above
identity
derived
usually system
followed
for n.m.r.
from the dimers,
simply assignments
(1) and
(2),
169
EXPERIMENTAL 19
Varian
F and 1H n.m.r.
spectra
were
recorded
at 40°C using
a
A56/60D
spectrometer, with CFC13 or TMS as external 19 Upfield F shifts are quoted as positive. G.1.c.
reference. was performed silicone
on a gas-density
gum
Molecular
weights
Reactions
of dimer
(a)
With
Dimer
were
dried
determined
(2) (1.2 q, 3.7 mmol) There
into water,
resultant
liquid
a single
compound
g.1.c.
was
30%
(Co1 'A').
on an AEI MS9masS
with
stirred
spectrometer.
vacuum
by q.1.c.
traces
layer
(5 ml)
The mixture removed,
to a cold trap.
The
and other,
separated
unidentified
by preparative
scale
as l-ethoxy-l-pentafluorocyclobutenyl-
hexafluorocyclobutane
(6) (nc) (1.0 q, 78%):
C, 34.6:
ethanol
(Co1 '0') to be essentially
of ethanol was
with
reaction.
fluorocarbon
under
component
and identified
was
an exothermic
the lower
was shown
The major
Analysis:
two columns;
ethanol
(P205) and transferred
species.
using
(2)
neutral
for two minutes. was poured
balance
(Co1 '0') or 20% di-isodecylphthalate
H, 1.6;
F, 59.4%;
Mf,
b.p.
131Oc;
350.
C10Fl10H5 requires: C, 34.29: H, 1.43; F, 59.71%; M, 350; Xmax 1711 -1 cm (C=C str); 15~ 98.9 (lF, triplet of triplets Jl = 16 Hz,
= 18 Hz; = CF-), 116.1 (2F, multiplet, 2-F), 121.1 (2F, J2 multiplet, l-F), 123.8 and 133.3 (4F, as AB, J = 228 Hz, 3-F) and 131.5
and 133.8
(CH3-, triplet
ppm
In an analogous stirred
with
mixture
was poured
reaction
ethanol
(5 ml)
liquid
complex
mixture.
component
separated
6H 1.40
J = 7 Hz).
(2) (1.4 q, 4.3 mmol)
the lower
shown
The three main
as disubstituted was
dimer
to a cold
(1.5 q) was
4-F);
(-CH2-, quartet,
was
for 18 h. at room temperature.
into water,
(P205) and transferred sultant
q.l.c.-m-s.
(2F, as AB, J = 223 Hz,
J = 7 Hz) and 3.97
layer removed,
trap under by g.1.c.
vacuum.
compounds,
The re-
(Co1 '0') to be a
components
by preparative
The
dried
were
identified
The major
C8F10(OEt)2. scale
q.1.c.
by
and identi-
fied as l-(1'- ethoxyhexafluorocyclobutyl)-2-ethmtrafluoro?cl@ butene
(7) (nc),
(1.0 q, 65%):
b.p.
192OC:
Analysis:
C, 38.4;
170 H, 2.5;
F, 50.3%;
M+,
F, 50.53%; H, 2.66; 111.2 (2F, multiplet, 123.9
and 133.3
376.
C12F1002H10
M, 376; 2-F),
Xmax
116.1
1685 cm-l
1.53
3.83
(CH3-, triplet
(-CH2-, quartet,
(b)
(20 ml) and
J = 7 Hz),
With
sodium
metal
was added
was
complete
was
slowly
reaction
under
was
to 90°C,
with
formation
left stirring
reduced
pressure'.
to dry ethanol
a mixture
added.
of dimers
There
of a white
(1)
was a
precipitate.
The
overnight
and the ethanol
removed
The residue
was distilled
in vacua
0.1 mm Hg) to give
by g.1.c.
J = 7 Hz)
ethoxide
reaction
mixture
J = 7 Hz),
J = 7 Hz).
(2) (2.6 g, 8.0 mmol)
vigorous
and 133.8
(CH3-, triplet,
(-CH2-, quartet,
(0.9 g, 39.1 mmol)
and when
AF
J = 4 Hz, l-F),
(4F, as AB, J = 224 Hz, 3-F) and 131.7 FH 1.40
Sodium
C, 38.30;
(C=C str);
(2F, triplet
(2F, as AB, J = 223 Hz, 4-F);
and 4.53
requires:
a colourless
(Co1 '0') to be a single
liquid
compound
(up
(2.3 g), shown
identified
as l-(1'-
ethoxyhexafluorocyclobutyl)-2,3,3-triethoxy-4,4-difluorocyclobutene
(8) (nc)
H, 5.0; H, 4.67; 112.7
(67%):
F, 35.0%; F, 35.51%;
3.96 and signal
4.42
(c)
solution various
was
Amax
C, 44.6;
re!yires:
1689 cm
122.8 and 133.1
quartets,
(6) with
J = 7 Hz, ratio
of compound
fluoride
CH3-
6H 3.90, 2:l:l)
and
resonances.
ion
(6) (0.76 g, 2.17 mmol), and DMF
SF
(4F, as AB, J = 219 Hz,
(5 ml) was
caesium
stirred
at room
for 30 minutes.
A small sample of the resultant and its 19 F n.m.r. spectrum recorded at
removed
temperatures.
These
indicated
the presence
(l'-ethoxyhexafluorocyclobutyl)-hexafluorocyclobutyl in solution:
6F 84.0
(very broad
anionic
centre
certain
integration).
bromine
(0.35 g, 2.19 mmol)
1 h.
C, 44.85:
(C=C str);
(2F, as AB, J = 219 Hz, 4-F):
(1.43 g, 9.4 mmol)
temperature
Analysis:
C16F804H20
at 1.5 due to overlapping
Compound
A mixture fluoride
l-F),
and 133.3
(all -CH2-'s,
centred
> 200°C;
428.
M, 428;
(2F, singlet,
3-F) and 130.5
b.p.
M+,
[151 and signals
The volatiles
singlet,
between
The residual
were
then
transferred
anion
-CF2-'S
was quenched
vacuum
to
(un-
at room temperature under
(9)
adjacent
119 and 138 ppm
solution
and stirred
of the l-
with for
to a cold
171 trap.
The
ferred
under
lower
(0.72 g) was identified
layer was removed,
vacuum shown
26.5:
dried
trap.
by g.1.c.
(10)
F, 51.5;
F, 50.78;
The resultant
Br,
(nc),
(79%):
Br, 17.1%.
17.82%;
signal,
b.p.
C10F120H5Br
adjacent
128.7
(2F, as AB, J = 221 Hz) and 131.2
With
(1) and
(20 ml) was
was removed
distilled liquid
adjacent
(69%):
125.7
115.3
(J = 1.5 Hz))
stirred
under
F, 51.1%;
1641 cm -1
at room
reduced
at 8.25.
125.9
reactions
a pale
(11)
requires:
yellow,
(nc),
F, 51.01%;
(C=C str. and C=O str.) and 132.5
(4F, as AB, J = 222
J = 20 Hz,
(11) decomposes
with
for 24 h.
and the residue
as l-hydroxy-2-(l'-hydroxy-
(2F, doublet,
Compound
and
temperature
pressure
C8F803H2
(broad)
l-F),
Hz, 3-F) and 131.6 ppm Similar
and
6H 1.63
and 4.20
(2) (3.0 g, 9.3 mmol)
(1.9 g) identified
(LF, singlet,
singlet
(4F,
126.0
(2F, singlet);
(ca. 60°C, 0.1 mm Hg) to give
Analysis:
1796 and
and 119.3
to >C(OEt)-),
hexafluorocyclobutyl)-4,4-difluorocyclobuten-3-one
xmax
C, 26.73:
6F 109.7
water
of dimers
acetone
viscous
Analysis:
J = 7 Hz).
excess
A mixture
The acetone
-CF2-'s
(J = 7 Hz) of doublets
(-CH2-, quartet,
molecular
compound
requires:
to ;CBr-),
complex
(CH3-, triplet
169OC;
no C=C str in I.R.;
(4F, as AB, J = 216, -CF2-'s
aqueous
liquid
(Co1 '0') to be a single
broad
(d)
(~205) and trans-
as l-ethoxy-l-(l'-bromohexafluorocyclobutyl)-hexa-
fluorocyclobutane
c,
to a cold
the separate
4-F):
on strong dimers
both
6H sharp heating. gave
(11) as
the only product.
(e)
With
and water
an equivalent
(94 ~1,
for 2 h. at room distillation
5.22 mmol) temperature
to leave
(Co1 '0') to consist were
of water
(2) (1.70 g, 5.25 mmol)
Dimer
separated
by preparative
liquid
g.1.c.
was
removed
components. to give
(10 ml) stirred
by
(2.06 g) shown
and two other scale
in ether
The mixture
and then the ether
a colourless of ether
was dissolved
was added.
by g.1.c These
l-(l'-hydroxy-
hexafluorocyclobutyl)-2,2,3,3,4,4-hexafluorocyclobutane
(13) (nc)
(0.59 g, 33%) and l-hydroxy-l-pentafluorocyclobutenyl-hexafluorocyclobutane and
(12)
(nc) (0.24 g, 14%).
24% respectively.
Yields
by g.1.c.
were
46
172 For
compound
H, 0.7;
(13):
F, 67.0%;
M, 342;
110 and 140 ppm
107OC;
I.R.
shows
(12):
highest
requires: no C=C
all unassigned;
For compound
Analysis:
M+, not observed,
(HF')., C8F120H2
i.e. M+-20 66.67%;
b.p.
b.p.
C, 28.1; peak
C, 28.07;
AF signals
str;
IS~, 3.7 lll°C;
at m/e = 322,
H, 0.58;
F,
between
(broad singlet).
Analysis:
C, 29.6:
H, 0.2;
H, 0.31; C8F110H requires: C, 29.81; M+, 322. F, 64.7%; 64.91%; 6F 99.9 (IF, M, 322; Amax 1721 cm (C=C str); triplet
(J = 15 Hz) of triplets
multiplet,
2-F),
121.5
(4F, as AB, J = 225 Hz, 3-F) Hz,
6H 4.25
4-F): When
stirred
(12) and
(f)
With
ml) was
added
5.65 mmol)
and ether solution
at room
rotary white
to give
in aqueous
(2F,
J = 12
both
compound
(11).
(2) (1.89 q, 5.83 mmol)
(20 ml) was
of ethylene
and the mixture
obtained.
This was
in ether
glycol
Vacuum
sublimation
rhombohedral
crystals
until
allowed removed
of the residue
was recrystallised
an to
on a
yielded
from Ccl4
identified
(10
(0.35 g,
stirred then
for 48 h and the ether
(1.21 g) which
large
116.3
and 134.8
(2F, doublet,
acetone,
to compound
to a mixture
temperature
evaporator. solid
127.5
qlycol
of dimer
homogeneous stand
and 132.6 ppm
hydrolysed
ethylene
slowly
l-F),
(broad resonance). overnight
(13) were
A solution
(J = 18 Hz), =CF-),
(2F, multiplet,
F,
a
at O°C
as bicycle-[5.2.-
01-2-spirohexafluorocyclobutyl-3,6-dioxa-8,8,9,9-tetrafluoronon1,7-ene
(14) (nc),
H, 1.1;
F, 55.3%;
H, 1.16;
(60%):
F, 54.91%;
CC14)
109.3
124.9
and 132.4
m.p.
M+ 346.
(2F, broad
54-55OC;
C10F1002H4
PI, 346;
x max
singlet,
Analysis: requires:
1688 cm-l
2-F),
121.4
C, 34.4; C, 34.68;
(C=C str) ; (2F, singlet,
(4F, as AB, J = 221 Hz, 3-F) and 131.2
AF (in l-F),
and 133.3
AH 4.80 (doublet J = 13 Hz, m?m (2F, as AB J = 224 Hz, 4-F); unassigned) and 4.80 (doublet of doublets Jl = 25 Hz and J2 = 3.5 Hz, unassigned).
(9) Dimer mmol)
were
With
dimethylamine
(2) (1.4 q, 4.3 mmol) transferred
under
and dimethylamine
vacuum
to a Carius
(1.4 q, 31.1
tube.
The tube
173 was
sealed
and allowed
reaction. opened
to warm;
and molecular
yellow
a mixture
there was
the tube had cooled
and the contents
removed pale
When
liquid
with water.
distilled
The
were
The monosubstituted
lower
by g.l.c.-m.s.
and a di-substituted
These
exothermic
temperature,
it was
layer was
(ca. 65OC, 0.1 mm Hg) to give
(1.4 g) shown
of a mono-
respectively).
shaken
a vigorous,
to room
separated
compound
(Co1 '0') to be
compound
(46 and 54%
by preparative
(a liquid)
a
was
scale
g.1.c.
identified
as
l-dimethylamino-2-heptafluorocyclobutyl-tetrafluorocyclobutene (15) (nc); Analysis: requires: str);
N, 4.1;
N, 4.01;
6F 104.4
F, 59.5%;
M+ 349.
F, 59.89%;
l-F),
125.7
134.0
(2F, as AB J = 228 Hz, 4-F) and 154.9
singlet,
and 132.8
Amax 1690 cm-1 (C=C 117.0 (2F, singlet,
M, 349; singlet, 2-F),
(2F, broad
(4F, as AB J = 228 Hz,
6H 3.31
;CF-);
The disubstituted
C10FllNH6
3-F), ppm
130.6
and
(lF, broad
(singlet).
compound
(a solid)
was
identified
as l-
dimethylamino-2-(l'-dimethylaminohexafluorocyclobuty~)-tetrafluorocyclobutene 51.3%;
M + 374.
50.80%;
(16) (nc); C12F10N2H12
M, 374;
triplet
Xmax
1683 cm-l
(J = 18) of triplets
l-F),
111.1
135.2
ppm
1:l each
Analysis:
and 124.9
C, 38.2:
requires:
2-F),
115.8
F,
(2F,
(2F, singlet,
(4F, as AB J = 222 Hz, 3-F) and 130.6
(2F, as AB J = 226 Hz,
4-F);
6H 2.72 and 3.13
and
(ratio
a singlet).
(h)
With
lithium
A mixture
chloride
of lithium
(2) (2.49 g, 7.69 mmol) temperature to a cold
for 3 h. trap.
The
washed
with water,
a cold
trap.
to be a single
chloride
and DMF
(1.22 g, 28.80 mmol),
(10 ml) was
The volatiles lower
dried
Analysis:
stirred
liquid
identified
was
shown
C, 26.7;
dimer
at room
transferred layer was
(P205) and transferred
The resultant compound
were
fluorocarbon
under
vacuum
removed,
under
by g.1.c.
vacuum
to
(Co1 '0')
as 1-chloro-2-(l'-chlorohexa-
fluorocyclobutyl)-tetrafluorocyclobutene 129Oc;
F,
H, 3.21;
cSF 103.4
(C=C str);
(J = 24),
H, 3.5:
C, 38.50;
F, 52.5;
(17) Cl,
(nc) (77%):
20.5%;
M+,
356
b.p. 35
(
A max
Cl).
M, 356); requires: C, 26.89; F, 53.22: Cl, 19.89%; -1 6F 114.1 (2F, multiplet, 2-F), 120.7 (C=C str); 1640 cm
C8F10C12
(2F, multiplet, (2F, singlet,
l-F), 4-F).
121.9
(4F, singlet,
3-F) and 129.6
ppm
174 Reactions
of trimer
(a)
With
Trimer two layers
neutral
(4) was
With
Sodium and when
was
added
sodium
for several
days with
ethanol.
and after
two weeks
g.1.c.
was
removed
in vacua
complete, stirred
under
in either
was
added
trimer
overnight
reduced
from methanol
C18F1503H15 A max
requires:
at 1.6, -CH2-'S
trimer
(15 ml)
(66%) 564.
Mi
M, 564;
F, 50.53%;
(2F, multiplet,
(lF, broad
multiplet,
)CF-)
(12F, unassigned);
6H
(CC14)
at 4.2.
(4) in aqueous
and water
The mixture
acidified
(dil. HCl). (50 ml).
on a rotary
evaporator
spectrum
to separate
with
reaction.
further.
of sodium
was
left stirring
The
lower
carbonate
with
overnight
addition
the lower
and then and dissolved
layer.
(2 x 50
The
(MgS04) and the ether
a yellow
unsuccessful
of
(3.4 g),
extracted
liquid
this to be a mixture.
were
temperature
in an exothermic
layer was removed
dried
to leave
at room
However,
layer was ether
combined water,
indicated
components
acetone
(5 ml) resulted
The upper
and the extracts
was then washed
pursued
and
F, 50.4%;
H, 2.66;
122 and 136 ppm
(3.4 g) to a mixture
reaction.
n.m.r.
(2.0 g)
(18) (nc),
(Ccl,) 107.9
lead to any detectable
in ether
a solid
With water
the trimer acetone
temperature.
and the residue
(low temperature)
H, 2.7;
176.4
ring),
between
Stirring did not
6F
(C=C str);
centred
(c)
C, 38.4: C, 38.30;
in unsaturated
and signals
ml)
Analysis:
1681 cm-l
CH3-'S
(20
as 1,3-djethoxy-2-(l'-ethoxyhexafluorocvclobutyl)-3-
52-53OC;
-CF2-
to ethanol
at room
pressure
heptafluorocyclobutyl-4,4-difluorocyclobutene m.p.
layer.
(4) (2.6 g, 5.4 mmol)
(cd. 60°C, 0.1 mm Hg) to give
was recrystallised
identified
The (Co1 '0')
ethoxide
reaction
was
of any products
(0.65 g, 28.3 mmol)
and the mixture
The ethanol
which
stirred
the presence
metal
ml)
sublimed
ethanol
did not homogenise
did not indicate
(b)
(4)
solution removed
(2.0 g).
A l9F
Various
attempts
and the reaction
was not
1 75
(d)
With
Trimer amine
diethylamine
(4) (3.3 g, 6.8 mmol)
(10 ml) with
vigorous
reaction
hydrofluoride. washed
stirring occurred
gave
n.m.r.
Molecular
a pale yellow
and g.1.c.
separate
(e)
sodium
To a suspension tetraglyme
(20 ml) with
the mixture carefully
dried
was
was
distilled shown
attempts
and so the reaction
to
was
trimer
the addition
were
bulked,
removed
complete
extracted
washed
with
(3 x
water, to leave
a
(Co1 '0') to be a
components.
after
amount
was
by distillation
by g.1.c.
in
(4) (3.3 g,
for 1 h. and then
(100 ml) and ether
the addition
for 1 h. on a steam
a small
(1.0 g, 25.6 mmol)
slowly
bath
was
and then
of a colourless
(Co1 '0') to be a highly
complex
and the complexity
complete,
the
flash
liquid
which
mixture.
of the product,
was
In the
was not pursued.
(a)
of dimer
With
A mixture stirred
into water
was
reaction,
of the low recovery
ferred
by l?F
shown
Various
temperature
and ca. 20 other
to give
Reactions
was
When
(3.1 g) shown
stirred
by g.1.c.
reaction
and the filtrate
This was
mixture.
added
at room
extracts
liquid
of ether
mixture
of diethylamine-
(0.1 mm Hg, up to
g).
borohydride
was
stirring.
into water
In a similar
view
of sodium
stirred
The ether
mixture
A
borohydride
(MgS04) and the ether
colourless
(1.7
unsuccessful
at -18OC
rapid
poured
50 ml).
distillation
to diethyl-
(ice-bath).
further.
With
6.8 mmol)
added
cooling
by filtration
liquid
were
slowly
precipitation
to be a complex
components
not pursued
with
This was removed
with water.
90°C)
was
and external
neutral
ethanol
of dimer
at room
(1) (1.1 g, 3.4 mmol)
temperature
and the lower
under
shown
(1)
vacuum
layer
to a cold
by g.l.c.-m.s.
substituted
compounds,
compounds.
The major
for 18 h. removed, trap.
and ethanol
The mixture
dried
The resultant
product
monosubstituted
was poured
(P205) and trans-
(Co1 '0') to be a mixture an addition
(5 ml)
liquid
(1.0 g)
of two mono-
and two disubstituted
compound
(0.61 g, 60%) was
176 separated
by preparative
scale
g.1.c.
and identified
2-heptafluorocyclobutyl-tetrafluorocyclobutene separated
was
which
identified
was
the addition
product
as l-ethoxy-
(19) (nc).
Also
(< 0.1 g, ca. 8% by g.1.c.)
as 1-ethoxy-2-hydro-2-heptafluorocvclobutyl-
pentafluorocyclobutane
(20) (nc) .
Other
components
were
not
characterised. For compound 1.0;
F, 59.5%:
1.43;
(19): M+,
F, 59.71%;
(2F, multiplet,
b.p.
350.
Xmax
116.3 3-F),
(lF, singlet,
J = 7 Hz) and 4.48
C10F120H6
requires:
C=C
6F 195.5
str;
113.6
(20); ,C,
3.48
was
stirred
above
(b)
(15)
(c) Dimer
was
(CH3-,
J = 7 Hz). H, 1.4%;
M, 370;
>CF-)
and signals
4.28
M+,
370.
I.R. shows
6H 1.62
a mixture
no
between
(CH3;
triplet
(-CH2-, quartet,
of dimer
The reaction
liquid
shown
J = 7
(1) and ethanol
mixture
by q.1.c.
as for g.
was
treated
as
to be a mixture was
identified
as
stirring
dimer
gave
(16)
removed
(1) (1.7 g, 5.2 mmol)
a mixture
(1.5 g) of
(17%).
liquid
added
cooling
the mixture
and molecular
a colourless
was
and external
complete,
identified
Thus
diethylamine
(1) (1.4 q, 4,3 mmol)
was
layer
was
(0.9 g, 20.0 mmol)
(83%) and compound
With
(5 ml) with
lower
(2F, as AB J = 229
1Jith dimethylamine
and dimethylamine
to give
1.62%;
127.2
AH 1.50
C, 32.4;
(J = 1 Hz)),
for 3 minutes.
The procedure
addition
and 133.8
components, the major one of which 19 (19) by F n.m.r. spectroscopy.
compound
compound
l-F),
,)F-);
(-CH2-, quartet,
32.43;
6F 111.2
and 134.4
Analysis:
reaction
and the resultant
of several
H,
(C=C str);
, very broad).
(-CH(
In a similar
requ_if_-es: C, 34.29;
(llF, unassigned);
(J = 7 Hz) of doublets Hz) and
130.8
(lF, multiplet,
and 138.5 ppm
H,
(2F, multiplet,
Hz, 4-F) and 179.4 ppm For compound
C, 34.1;
1695 cm
(4F, as AB J = 229 Hz,
triplet
Analysis:
C10F110H5
M, 350;
2-F),
154OC;
was
slowly
shaken
distilled
(1.2 q) which
to diethylamine
(ice-bath). with
When
water
the
and the
(ca. 85OC, 0.1 mm Hq) rapidly
darkened.
This
as 1-diethylamino-2-heptafluorocyclobutyltetra-
fluorocyclobutene
(21) (nc),
(74%);
Analysis:
F, 55.0%;
M+ 377.
177 C12F11NH10 requires: str);
6F 104.2
125.9
and 132.0
F, 55.44%;
M, 377;
(2F, multiplet,
2-F),
~max
(4F, as AB J = 226 HZ, 3-F),
(2F, as AB J = 228 Hz, 4-F) and 159.2 ppm IS~ 1.42
1676 cm-l (C=C (2F, multiplet, I-F),
116.0
(CH3-, triplet,
130.1
and 133.6
(lF, singlet,
J = 7 Hz) and 3.55
:CF-);
(-CH2-, quartet,
J =
7 HZ).
(d)
With
Dimer and cooled
at -18OC
10.40 mmol) was
trimethylamine
(1) (1.42 g, 4.38 mmol) whilst
in ether
filtered
under
(10 ml) was
nitrogen
shown
to be a quarternary
water
and resultant
to fluoride
was dissolved
a solution added
to give ammonium
a white salt
attempts
the reaction
with
to separate
evaporator
and the resultant
to be a complex
components
neutral
were
mixture.
unsuccessful
and
ethanol
(3) (2.0 g, 4.1 mmol)
and the lower
layer
under
vacuum
q) was
shown
by g.l.c.-m.s.
trimer
(3), two monosubstituted
8:l and traces were
was
temperature.
ferred
products
in
(3)
for 8 h. at room
into water
soluble
was not pursued.
Trimer ml)
(0.46 g),
solution shows only a resonance corresponding 19 F n.m.r. spectrum). The ether was
of trimer
(a)
solid
(extremely
ion in its
from the filtrate on a rotary 19 oil shown by F n.m.r. spectroscopy
Reactions
(5 ml)
(1.05 g,
The mixture
slowly.
removed
Various
in ether
of triethylamine
to a cold
removed, trap.
with
dried
ethanol
was
(P205) and trans-
The resultant
products
liquid
(1.8
of
(ca. 90%) in the ratio
product.
by preparative
(10
then poured
(Cal. '0') to be a mixture
of a disubstituted separated
stirred
The mixture
The monosubstituted
scale
g.1.c.
and identified
as l-ethoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl~tetrafluorocyclobutene
(22)
(nc) (major product),
and 4-ethoxy-
l-(l'-heptafluorocyclobutylhexafluorocyclobutyl~-tetrafluorocyclobutene
(231 (nc).
For compound 0.7; 0.98;
F, 62.7%; F, 63.09%;
(22): M+,
b.p.
512.
M, 512;
202OC;
C14F170H5 hmax
Analysis: requires:
1678 cm-l
C, 32.5:
H,
C, 32.81;
H,
(C=C str);
sF 174.2
178 >CF-)
(lF, singlet, unassigned):
dH 1.60
For compound observed,
peak
C, 32.81;
(CH3-, triplet,
(23);
Analysis:
at m/e = 483,
H, 0.98%;
With
Sodium (20 ml)
sodium
metal
and when
temperature,
pressure.
vacuum
ratio
(0.6 g, 26.1 mmol)
, not
requires:
)CF-)
6F
and signals (CH3-,
J = 7 Hz).
was dissolved
solution
The mixture
material
was
stirred
There
was
was
for 16 h. at
was removed
in the residue
to room
added.
under
reduced
transferred
trap
and the resultant
liquid
(Co1 'A') to consist
of two components
in the approximate
3:l
to a cold
was
the methanol
in methanol
had cooled
(3) (4.2 g, 8.6mmol)
and then
Volatile
+
(C=C str);
AH 1.53
(-CH2-, quartet,
M
methoxide
reaction.
temperature
C14F170H3
1710 cm-l
(lF, singlet;
the resultant
trimer
an exothermic
g.1.c.
(-CH2-,
H, 0.8%;
(15F, unassigned);
= 7 Hz) and 4.22
(b)
g.1.c.
(16F
J = 7 Hz) and 4.58
C, 32.7;
imax
174-5
112 and 134 ppm
triplet,J
under
108 and 133 ppm
i.e. IIf-29.
M, 512;
(lF, singlet: =CF-),
between
room
between
J = 7 Hz).
quartet,
98.0
and signals
(3.6 g).
to give
The
These
a liquid
liquid
were
separated
shown
by preparative
by
scale
and a solid.
(major product)
was
identified
as 1,3,3-tri-
methoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl)difluorocyclobutene 34.7:
H, 1.9;
34.48;
H, 1.72;
172.6
(24)
6F (14F, unassigned);
M+,
F, 54.60%;
(lF, singlet,
( lC(OCH3)2,
(nc):
F, 54.2%;
>CF-)
hH 3.75
b.p. 522.
> 210°C;
Analysis:
C15F1503Hg
14, 522;
Xmax
and signals (=C-0CH3,
1679 cm-l
between
singlet)
C,
requires:
C,
(C=C str);
111 and 133 ppm
and 4.30
singlet).
The solid
was
recrystallised
from Ccl4
and identified
as
l-methoxy-2-(l'-heptafluorocyclobutylhexafluorocyclobutyl)-4,4Analysis: difluorocyclobuten-3-one (25) (nc) m.p. 53-54OC; + M 476. C13H150H3 requi_rys: F, 59.87%; M, 476; -i A max 1815 cm (C=C str) and 1641 cm (C=O str); 6F (in CC14)
F, 59.7%; 178.6
(lF, pentet
133 ppm
J = 23 Hz, >CF-)
(14F, unassigned);
bH
and signals
(in CC14)
4.65.
between
111 and
179 A sample
of compound
for 8 days to give identified
(c)
A mixture
of its infrared
of trimer
(20 ml) was
acetone
was removed
sublimed
in vacua
;CF-)
c,
under
reduced
31.1;
and signals
in tetraglyme with
addition steam The
lower
sodium
layer
to give with
C12F15H3 xmax
unsaturated
at room
118 and
133 ppm
(e)
With
Procedure and diethylamine identified
the
for 1 h. on a
temperature
and the residue
overnight. flash
to be
The two fractions
C, 33.3;
were
(27) (nc)
H, 0.7;
H, 0.69;
SF, 109.6
(79%):
F, 65.6%: F, 65.97%;
(2F, singlet,
(lF, singlet
(12F, unassigned):
J = 3 Hz) and 6.59
When
as l-(l'-heptafluorocyclobutylhexa-
c, 33.33:
176.1
(3) (6.0 g, 12.3
cooling.
(1.1 g) shown by g.1.c.
layer.
(C=C str); ring),
J = 22 Hz,
(2.3 g, 53.7 mmol)
was heated
removed
a liquid
the lower
requtres:
181-183°C;
(14F, unassigned).
trimer
and external
the mixture
Analysis:
1608 cm
(4.8 g)
(C=C str) and
(lF, pentet
slowly
left stirring
and identified
164OC;
solid
m.p.
1804 cm
fluorocyclobutyl)-3,3-difluorocyclobutene b.p.
The
C12F;1502H requires:
borohydride
added
(3.1 g) was
identical
a white
(90%):
462.
Amax
of sodium
complete
and then
and aqueous
temperature.
borohydride
stirring
distilled
combined
that of
and the residue
115 and 137 ppm
(20 ml) was
was
(nc)
M+,
M, 462;
between
rapid
bath
(26)
rSF (H20) 178.2
To a suspension
mmol)
with
(26),
'-heptafluorohexafluorocyclobutyl)-
F, 62.0%;
F, 61.69%;
With
pressure
(90°C, 0.1 mm Hg) to give
(C=O str);
(d)
spectrum
for 24 h. at room
4,4-difluorocyclobuten-3-one
31.17; -1 1640 cm
derivative,
(3) (5.6 g, 11.5 mmol)
stirred
as l-hydroxy-2-(1
c,
hydroxy
water
acetone
Analysis:
to the atmosphere
sample.
With
identified
left open
the corresponding
by comparison
an authentic
(25) was
>CF-)
AH 3.35
M+,
M, 432; -CF2-
and signals (-CH2-,
432.
in between
triplet
(=CH-, singlet).
diethylamine was
Thus,
as for m.
(5 ml)
gave
trimer
a pale yellow
as l-diethylamino-2-
(3) (3.4 g, 7.0 liquid
product
(1 I-heptafluorocyclobutylhexa-
fluorocyclobutyl)-tetrafluorocyclobutene
(28) (nc)
(73%):
nUlI01)
(2.9 Cr)
180
Analysis:
F, 60.3%;
539;
Mf,
C16F17NH10
requires:
F, 59.93%;
8F 172.9 (lF, singlet, hmax 1662 cm-l (C=C str); M, 539; and signals between 103 and 133 p.p.m. (16F, unassigned); (CH3-, triplet
1.36
(f)
With
J = 7 Hz) and 3.34
pentafluorophenyl
Pentafluorobromobenzene a mixture
of ether
nitrogen,
to -3OOC.
21.5 mmol) between
was added
allowed
overnight. ether
to warm
Water
extracted
organic
molecular
being
to room
This was removed
distilled
then washed
(0.1 mm,
the same,
pure
compound.
and identified
Analysis:
36.83:
benzene C6F5
ring),
ring),
signals
C, 36.9:
F, 63.17%; 138.1
161.8
between
trimer
layer
combined
with water,
to give The
separated, with
dried
the
(MgS04)
The residue
a pale liquid
yellow was
compound,
was
liquid
shown
by
the solid
The solid was recrystallised
as perfluoro-1-parabiphenyl-2-cl'-
cyclobutylcyclobutyl)cyclobutene 108OC;
solution,
and left stirrinq
the aqueous
(2.41 g).
in
under
maintained
complete
evaporator.
80°C)
dissolved
and the resultant
and the extracts
on a rotary
solid
being
was
temperature
(Co1 '0') to be > 90% of a single
from ether
c,
slowly
(5'0ml) was added,
(1.17 g) and a white g.1.c.
the addition added
(2 x 20 ml)
layer.
and the ether
was
was
(13 ml of a 1.65M
the temperature
When
J = 7 Hz).
(12 ml) and cooled,
lithium
slowly,
(3) (3.70 g, 7.61 mmol) mixture
and hexane
n-Butyl
hH
lithium
(5.3 g, 21.5 mmol)
(18 ml)
-20 and -3OOC.
(-CH2-, quartet
>CF-)
(29) (nc) F, 62.8%;
M, 782; (2F, ortho
(2F, meta
6F
M+ 782.
ring),
m.p.
107-
requires: C24F26 (4F, di.substituted
(Et20) 136.4
F, C6F5 ring),
F, C6F5
109 and 128 ppm
(ca. 58%);
150.5
171.7
(lF, para
F,
(lF, \CF-) and
(16F, unassigned).
ACKNOWLEDGEMENTS
We thank (to G.T.) award.
the Science
and 1-C-I.
Ltd.,
Research
Council
Mond Division
for a C.A.S.E.
for co-operation
award in this
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