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Патент USA US2404706

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Patented July 23, 1946
2,404,706
UNITED STATES PATENT OFFICE
2,404,706
FLUORINATION
Jesse Harmon, Wilmington, DeL, assignor to E. I.
du Pont de Nemours & Company, Wilmington, '‘
Del., a corporation of Delaware
No Drawing. Application October 4, 1943,
>
Serial No. 504,951
5 Claims.
1
(Cl. 260—653)
2
.
This invention relates to the ?uorination of se
being a halogen, with a ?uorinated methane in
lected organic halogenated compounds, and more
particularly to the ?uorination of unsaturated or
ganic compounds by means of an organic ?uorin
ating agent.
Previous to the present invention, practically
the only method for preparing ?uorine-contain
ing organic compounds has been to replace chlo
rine with ?uorine by means of various inorganic
5
the presence of from about 0.1% to about 20% by
weight of the reacting materials of a Friedel
Crafts type catalyst which is a chloride of a poly
valent metal cation.
A preferred embodiment of this invention
comprises heating hexachloropropylene with
chlorodi?uoromethane at a temperature within
the range of from about 100° C. to about 200° C‘.
reagents such as metallic ?uorides including silver 10 in the presence of an amount of anhydrous
?uoride, antimony ?uorides and mercuric ?uoride
aluminum chloride, calculated on the basis of
in the presence or absence of hydrogen ?uoride.
' the sum‘ of the weights of the hexachloropropy
Such inorganic reagents are hazardous and ex
lene and chlorodi?uoromethane, within the
pensive, and their use is very restricted in appli
range of from 0.1% to 20%.
7.
cation.
15
By the expression “trihalomethyl ethylenic
I have now discovered a process whereby tri
compound” as used herein and in the appended‘
halomethyl ethylenic compounds may be ?uorin
claims is meant an organic compound contain
ated readily to provide ?uorine-containing‘ tri
halomethyl ethylenic compounds.
ing the grouping
Accordingly, this invention has as an. object a 20
new method of producing ?uorine-containing or
ganic compounds. A further object is ‘a safe,
?exible, practicable and economical method for
’
OX2
.
=0
wherein the X substituents are halogen atoms
and the double bond is a linkage in an aliphatic’
producing ?uorinated organic compounds. A still
chain or in an alicyclic ring.
further object is the employment as ?uorinating 25 The method for carrying out the reaction var-1
agents of readily and commercially available ?uo
ies to ‘some extent with di?erent types of tri
rine compounds. A still further object is the
halomethyl ethylenic compounds, but the usual
provision of a process which proceeds smoothly
procedure consists in placing a given amount of
and easily without undesirable side reactions.
trihalomethyl ethylenic compound such as hexa
Additional objects will become apparent from an 30 chloropropylene in a si1ver~lined autoclave with
examination of the following description and
chlorodi?uoromethane and a small amount of
claims.
’
anhydrous aluminum chloride catalyst, and then
These and other objects and advantages are ac
heating the reaction mixture at about 100 to
complished by the herein described invention
200° C‘. with agitation for several hours.
which broadly comprises heating a trihalomethyl
ethylenic compound, 1. e., a compound containing
The following examples, in which proportions
are given in parts by weight unless otherwise
speci?ed, are given for illustrative purposes and
a group having the general formula
are not intended to place any restrictions or limi
tations on the herein described invention:
wasI
40
wherein the X substituents are halogens, and at
least one of the X substituents is a halogen having
an atomic weight of greater than 30, with a
?uorinated methane in the presence of a Friedel
Crafts type catalyst.
-
.
In a more restricted sense this invention com
prises heating at a temperature within the range
of from about 100° C. to about 200° C, a compound
having the general formula X3C—CY=CY2
Example I
A silver-lined high pressure reaction tube was
charged with 15 parts of anhydrous aluminum
chloride, 100 parts of hexachloropropylene and
45 150 parts of chlorodi?uoromethane.
The re
actor was agitated and heated at 150° C. for
10 hours, then at 200° C. for 2 hours. After
cooling and releasing the pressure, the liquid
solid reaction mixture was treated with Water
wherein the X substituents are halogens, at least 50 and. the liquid was separated by decantation.
one of the X substituents having an atomic weight
The organic layer was washed with dilute aque
of greater than 30, and the Y substituents are
ous sodium hydroxide solution, then Water, and
monovalent radicals selected from the group con
was dried and fractionally distilled through a
sisting of hydrogen, halogens and monovalent
precision still when there were isolated: 68 parts
alkyl radicals, at least one of the Y substituents 55 CHCls, B.P. Gil-62° 0., ND“? 1.4448; 41.3 parts
2,404,706
3
4
CFs—CCl=C'Cl2, B.P_ 86-88" 0., ND20 1.4103; and
4 parts CF2Cl-C‘Cl=CClz, BE’. 128° C.
Example II
The trihalomethyl ethylenic compounds hav
ing one or more halogen atoms connected direct
ly to the carbon atoms bearing the double bond
are preferred since they are more stable and their
trihalomethyl groups are more readily ?uori
nated. Optimum results are had when the tri
On repeating Example I at 100° C. there were
isolated:
halomethyl ethylenic compound subjected to
Compound
Pvaiéizgkllaty BoilingCrange, ND20
3 _______________________ __
CFz-CC1=OC]Z _____________ __
CFzC1—-CCI=CC1z_.
.
CFCh-OOI=CC12 ___________ __
OCl3—OOl=CCl2 ____________ __
58
_
?uorination in accordance with this invention
has the general formula XaC—CY=CY2 wherein
10 the X substituents are halogens of which at least
.one is a halogen having an atomic weight of
greater than 30, the Y substituents are mono
valent radicals selected from the group consist
1. 4390
' 8
___
1. 4094
3. 5
25/15 mm ____ __
1. 4596
4. 5
67
53-55/15 mm___
35-36/2 mun..-
1. 5015
l. 5490
ing of hydrogen, halogens and monovalent hy
drocarbon radicals, and at least one of the Y sub
As hereinbefore stated, my novel process com
stituents is a halogen, and particularly when the
trihalomethyl ethylenic compound contains not
more than 10 carbon atoms.
The present process _is broadly applicable to
fluorinated methanes and particular signi?cance
prises fluorinating a trihalomethyl ethylenic
compound wherein at least one of the three
halogens in the trihalomethyl group has an
atomic weight of greater than 30, with a ?uori
nated methane in the presence of a Friedel
is attached to the use of the commercially avail
able ?uorinated methanes. Included among said
?uorinated methanes are dichloro?uoromethane,
Crafts type catalyst. The resultant ?uorinated
products contain a group having the general
formula
25
.
dichlorodi?uoromethane, chloro?uoromethane,
chlorodi?uoromethane, bromodi?uorometha-ne,
di?uoromethane, chlorotri?uoromethane; ?uoro
trichloromethane, tri?uoromethane and tetra
wherein n is a positive integer within the range
?uoromethane.
I
of from 1 to 3 and the X substituents are halo
The catalysts employed in the present process
gens having an atomic weight of greater than 30.
It is to be understood that any trihalomethyl 30 are Friedel-Crafts type catalyst-s which are chlo
rides 0r bromides of polyvalent metal cations,‘ and
ethylenic compound in which at least one of the
include such salts as aluminum chloride, alu
three halogens in the trihalomethyl group has
minum bromidebferric chloride, zinc chloride,
an atomic weight of greater than 30 may be flu~
stannic chloride and the like. The proportion of
orinated according to my novel process. How
catalyst employed may vary within relatively
ever, on account of the greater ease with which 35
the reaction proceeds therewith, the preferred
wide limits'depending largely upon the nature'of
the reactants and the products desired. Gener
ally speaking, desirable results are obtained with
pounds selected from the group of compounds
the use of small amounts of catalyst correspond
having the general formula X3C--CY=CY2,
wherein the X substituents are halogens of which 40 ing to from about 0.1% to 20% by weight of the
materials used. Advantageous results are some
trihalomethyl ethylene compounds are com
at least one is a halogen having an atomic
weight of greater than 30 and the Y substituents
are monovalent radicals selected from the group
consisting of hydrogen, halogens and monovalent
hydrocarbon radicals. Examples of monovalent
hydrocarbon radicals represented by Y in the
above formula are: methyl, ethyl, isobutyl, amyl,
hexyl and cyclohexyl radicals.
It is to be understood that the trihalomethyl
ethylenic compounds ?uorinated by the processv
of this invention contain the group
times obtained by using a combination of catae
lysts. The time required for carrying out the re;
actions may vary from a few minutes to several
days depending upon the nature of the reactants‘
and the other operating'conditions such as‘ terns
peratu're, pressure and catalyst. In general it‘is‘
preferable to carry out the reaction in the absence
of water.
}
"
‘
-
The process may be operated continuously or
intermittently.
Additional ?uorinated methane
may be added during the course of the reaction.
The by-product halogenated methanes such ‘as
wherein the X substituents are halogens, at least '
one of which is a halogen having an atomic
chloroform in‘ the examples may be reconverted
into ?uoromethanes by well known commercial
processes and recycled. The reaction may be
carried out in a closed system in‘ the liquid or
vapor phase, or in the vapor phase by mixing
group are:
>
the vapors of the trihalomethyl ethylenic com
60 pound and ?uorinate‘d methane and passing the
mixture through a hot reaction tube containing
the Friedel-Crafts type catalyst. The pressure
I I
I l
at which the reaction is carried out is dictated
euro-0:? and (HMO-0:?
by the vapor pressure and otherpropertie's of
In. addition to hexachloropropylene disclosed in 65 the reactants and products. Generally, however;
Examples I and II, trihalomethyl ethylenic com
it is carried out at superatmospheric pressures.
pounds which may be ?uorinated by the proc
The temperature at ‘which the reaction is e'f
ess'of this invention include: ClF2C—-CC1=CF2,
fected may vary over a fairly wide range, deh
pending largely upon the nature of the reactants,
the catalyst, the ‘results desired; and the other
conditions of the reaction. However, it is .neces~
sary to carry out the reactions at an elevated
weight of greater than 30.
Examples of said
Trihalomethyl ethylenic compounds in which the
ethylenic double bond is present in a cyclo
temperature.
Optimum‘ yields are usually obL
tained at temperatures within the range of from
aliphatic ring’ as in cyclohexene may also be used. 75 about 1100 to 200° 0., but higher temperatures, ‘be’
5
2,404,700
6
low that at which decomposition of the reactants
and/or products occurs, are sometimes desirable.
parting from the spirit and scope thereof, it is to
be understood that I do not limit myself to the
The reactions may be carried out in any suit
able reaction vessel whose materials of construc
tion are resistant to the action of the reactants
and catalysts, and which are capable of with
standing heat and pressure, such as stainless
steel, silver and the like. The reaction is pref
speci?c embodiments thereof except as de?ned
in the appended claims.
Having described the ‘present invention, the
following is claimed as new and useful:
1. The process for preparing a compound hav
ing the general formula FnX(3_n)C-CY=CY2
wherein n is a positive integer within the range
of from 1 to 3, the X substituents are halogens
having an atomic weight of greater than 30 and
erably carried out with agitation, but agitation
is not always necessary. The reaction and the
separation or isolation of the products may be
carried out simultaneously or in separate steps.
The ?uorinated products prepared in accord
ance with this invention are trihalomethyl ethyl
enic compounds in which at least one of the
three halogen atoms in the trihalomethyl group
is a ?uorine atom. Said products have the gen
eral formula FnX(3~n)C—-CY=CY2 in which for
mula n is a positive integer within the range of
‘from 1 to 3, the X substituents are halogens hav
ing an atomic weight of greater than 30 and the
Y substituents are monovalent radicals selected
from the group consisting of hydrogen, halogens
and monovalent hydrocarbon radicals. It is to
the
Y substituents are monovalent radicals
selected from the group consisting of hydrogen,
halogens and monovalent hydrocarbon radicals,
at least one of the Y substituents being a halogen,
which comprises heating a compound having the
general formula FmX(a-m)C—CY=CYz,. wherein
m is a number smaller than 11. selected from the
group consisting of zero and positive integers less
than 3, the X substituents are halogens having an
atomic weight of greater than 30 and the Y sub
stituents are monovalent radicals selected from
the group consisting'of hydrogen, halogens and
be understood that a mixture of iluorinated -
products in which n is l, 2 and 3 may be ob
tained upon ?uorination of a given trihalomethyl
ethyl'enic compound, e. g. a trichloromethyl
ethylenic compound, but the compounds are us
ually easily separated into de?nite fractions by :
conventional methods such as fractional distilla
tion. The relative proportions of the mono-, di
and tri?uoromethyl ethylenic compounds ob
monovalent hydrocarbon radicals, at least one of
the Y substituents being a halogen, with a
fluorinated methane in the presence of an an
hydrous Friedel-Crafts type catalyst.
2. The process according to claim 1 wherein
the heating is effected at a temperature within
the range of from about 100‘? C. to about 200° C.
3. The process for preparing a compound hav
ing the general formula FnX(3-n)C—-CY=CY2
wherein n is a positive integer within the range of
tained will depend upon the reactants and condi
from 1 to 3, the X substituents are halogens hav
tions.
" ing an atomic weight of greater than 30 and the
By way of illustration, the ?uorination of hexa
Y substituents are halogens, which comprises
chloropropylene by chlorodi?uoromethane in the
heating a compound having the general formula
presence of aluminum chloride is represented be
FmX(3—-m)C-—CY=CY2, wherein m is a number
low:
smaller than n'selected from the group consisting
U of zero and positive integers less than 3, the X
substituents are halogens having an atomic
Weight of greater than 30 and the Y ‘substituents
ing reagents. However, it is surprising that the
are halogens, with a ?uoromethane in the
presence of an anhydrous Friedel-Crafts type
catalyst which is a chloride of a polyvalent metal
cation.
4. The process for preparing a compound hav
extremely stable ?uorinated methanes ‘such as
ing the general formula FnX(3—n)C—CY=CY2
chlorodi?uoromethane can be used as a source of
wherein n is a positive integer within the range of
It is well known that the halogens in certain
halogenated hydrocarbons can be replaced with
?uorine by means of various inorganic ?uorinat
from 1 to 3, the X substituents are halogens hav
ing an atomic weight of greater than 30 and the
Y substituents are halogens, which comprises
enic group.
heating a compound having the general formula
‘The present invention is particularly advan
tageous in that it affords a safe, ?exible, practic
FmX(3_m)C—CY=CYz, wherein m is a number
able and economical process of ?uorinating or- .' smaller than n selected from the group consisting
ganic compounds of the character herein de
of zero and positive integers less than 3, the X
substituents are halogens having an atomic
scribed. One of the advantages of said process
weight of greater than 30 and the Y substituents
is that ?uorinated methanes which may be used
in this invention are commercially available; and
are halogens, with chlorodi?uoromethane in the
that said fluorinated methanes, such as chlorodi 60 presence of anhydrous aluminum chloride.
5. The process for preparing a compound hav
?uoromethane, which are extremely stable, can
be used as a source of ?uorine for selectively
ing the general formula FnC1(3—n)C-C‘C1=CC12
?uorinating trihalomethyl ethylenic compounds
wherein n is a positive integer within the range
without affecting the ethylenic group. Another
of from 1 to 3, which comprises heating hexa
advantage is that the process may be operated
chloropropylene with chlorodi?uoromethane in
with a relatively small amount of expensive cat
the presence of anhydrous aluminum chloride at
alyst and that the reaction proceeds smoothly
a temperature within the range of from‘about
and easily without undesirable side reactions.
100° C. to 200° C. and thereafter recovering the
fluorine for selectively ?uorinating trihalomethyl
ethylenic compounds without affecting the ethyl
As many apparently widely different embodi
ments of this invention may be made without de
70
compound FnC1(3—n)C—CC1=CC12 by distillation.
JESSE HARMON.
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