Note: Descriptions are shown in the official language in which they were submitted.
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
PROCESS FOR THE PRODUCTION OF CHLORINATED PROPANES AND PROPENES
FIELD
[0001] The present
invention relates to processes for the production of chlorinated
propanes and/or propenes. The processes are capable of providing useful
intermediates with
enhanced regioselectivity, while also producing undesirable byproducts at
lower
concentrations, than conventional processes.
BACKGROUND
[0002]
Hydrofluorocarbon (HFC) products are widely utilized in many applications,
including refrigeration, air conditioning, foam expansion, and as propellants
for aerosol
products including medical aerosol devices. Although HFC's have proven to be
more climate
friendly than the chlorofluorocarbon and hydrochlorofluorocarbon products that
they
replaced, it has now been discovered that they exhibit an appreciable global
warming
potential (GWP).
[0003] The search
for more acceptable alternatives to current fluorocarbon products has
led to the emergence of hydrofluoroolefin (HFO) products. Relative to their
predecessors,
HFOs are expected to exert less impact on the atmosphere in the form their
lower GWP.
Advantageously, HFO' s also exhibit low flammability and low toxicity.
[0004] As the
environmental, and thus, economic importance of HFO's has developed, so
has the demand for precursors utilized in their production. Many desirable HFO
compounds,
e.g., such as 2,3,3,3-tetrafluoroprop-1-ene or 1,3,3,3- tetrafluoroprop-l-ene,
may typically be
produced utilizing feedstocks of chlorocarbons, and in particular, highly
chlorinated
propanes, e.g., tetra- and pcntachloropropanes.
[0005]
Unfortunately, these higher chlorides have proven difficult to manufacture
using
acceptable process conditions and in commercially acceptable
regioselectivities and yields.
For example, conventional processes for the production of pcntachloropropanes
provide
unacceptable selectivity to the desired pentachloropropane isomer(s), i.e.,
1,1,2,2,3-
pentachloropropane, require the use of high intensity process conditions
and/or catalyst
systems that are difficult to utilize in large scale production processes
and/or that are not
1
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
recoverable once used. Other conventional processes may be limited to the
addition of a
single chlorine atom per reaction pass, and so must be repeated until the
desired number of
chlorine atoms has been added, with each additional step requiring additional
capital, energy,
and other cost investment. Still others require starting materials that are
either cost
prohibitive, have limited availability or both.
[0006] Further, the
dehydrochlorination steps required to create alkenes from a feedstream
comprising alkanes conventionally are conducted with the use of caustic,
resulting in large
quantities of waste water including low value by-products such as sodium
chloride.
Conventional processes rely on many such dehydrochlorination steps, thus
multiplying the
amount of waste water that must be treated prior to disposal.
[0007] It would
thus be desirable to provide improved processes for the production of
chlorocarbon precursors useful as feedstocks in the synthesis of refrigerants
and other
commercial products. More particularly, such processes would provide an
improvement over
the current state of the art if they provided a higher regioselectivity
relative to conventional
methods, required low intensity process conditions, and/or made use of
catalyst systems
and/or initiators that are recoverable or otherwise reusable, or were capable
of the addition of
multiple chlorine atoms per reaction pass as compared to conventional
processes. Further
advantages would be provided if lower cost and/or more widely available
starting materials
could be utilized.
BRIEF DESCRIPTION
[0008] The present
invention provides efficient processes for the production of chlorinated
propanes and/or propenes. Advantageously, the processes make use of 1,2-
diehloropropane,
a by-product in the production of chlorohydrin, as a low cost starting
material. And, at least
one chlorination step of the process is conducted with a catalyst that
provides a
regioselectivity of at least 5:1 to one chloropropane intermediate. In some
embodiments,
multiple chlorine atoms may be added per pass, while in others, the catalyst
may be
recoverable and reusable after the process. In some embodiments, further
advantages may be
provided by conducting one or more dehydrochlorinations catalytically, rather
than with
caustic. Less waste water is thus produced, and anhydrous HC1 may be produced.
Further
2
81779767
cost savings are provided in that low intensity process conditions, e.g., low
temperatures, low
pressure and liquid phase reactions, are utilized. Finally, multiple
chlorinations, involving
multiple catalysts, may be conducted in the same reactor, providing capital
and operating cost
savings.
[0009] In one aspect, the present invention provides a process for the
production of chlorinated
propanes and/or propenes from a feedstream comprising 1,2-dichloropropane. At
Least one
chlorination step of the process is conducted in the presence of a catalyst
that provides a
regioselectivity of at least 5:1, or at least 10:1, or at least 20:1, to one
chloropropane intermediate.
In some embodiments, the catalyst may comprise a Lewis acid, a nonmetallic
iodide, an inorganic
iodine salt, less than 10,000 ppm elemental iodine or combinations of these.
The source of
chlorine atoms may comprise either chlorine gas, sulfuryl chloride or both.
The chlorinated
propene may comprise from 3-4 chlorine atoms.
[0009a] In an embodiment, the invention relates to a process for the
production of 1,1,2,2,3-
pentachloropropane from a feedstream comprising 1,2-dichloropropane comprising
catalyzing at
least one chlorination step with one or more regioselective catalysts to
regioselectively afford
1,1,2,2,3-pentachloropropane at a ratio of at least 20:1 relative to other
pentachloropropane
isomers, wherein the chlorination step occurs at a pressure of 100 kPa to 2000
kPa; wherein the
temperature is less than 100 C; and wherein the regioselective catalyst
comprises aluminum
chloride, an inorganic iodine salt, less than 10,000 ppm elemental iodine, or
a nonmetallic iodide
comprising one or more iodobenzenes or halogenated iodobenzenes,
phenylchloroiodonium
chloride, diaryliodonium salts, iodinated polymers, iodoxy compounds, iodoso
compounds, iodine
mono- or trihalides, iodine oxides, or derivatives or combinations of any
number of these.
DETAILED DESCRIPTION
[0010] The present specification provides certain definitions and methods
to better define the
present invention and to guide those of ordinary skill in the art in the
practice of the present
invention. Provision, or lack of the provision, of a definition for a
particular term or phrase is not
meant to imply any particular importance, or lack thereof. Rather, and unless
otherwise noted,
terms are to be understood according to conventional usage by those of
ordinary skill in the
relevant art.
3
CA 2859168 2017-09-27
i I
CA 2859168 2017-05-11
81779767
[0011] The terms "first", "second", and the like, as used herein do not
denote any order,
quantity, or importance, but rather are used to distinguish one element from
another. Also, the
terms "a" and "an" do not denote a limitation of quantity, but rather denote
the presence of at
least one of the referenced item, and the terms "front", "back", "bottom",
and/or "top", unless
otherwise noted, are merely used for convenience of description, and are not
limited to any
one position or spatial orientation.
[0012] If ranges are disclosed, the endpoints of all ranges directed to the
same component
or property are inclusive and independently combinable (e.g., ranges of "up to
25 wt.%, or,
more specifically, 5 wt.% to 20 wt.%," is inclusive of the endpoints and all
intermediate
values of the ranges of "5 wt.% to 25 wt.%," etc.). As used herein, percent
(13/0) conversion is
3a
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
meant to indicate change in molar or mass flow of reactant in a reactor in
ratio to the
incoming flow, while percent (%) selectivity means the change in molar flow
rate of product
in a reactor in ratio to the change of molar flow rate of a reactant.
[0013] Reference throughout the specification to "one embodiment" or "an
embodiment"
means that a particular feature, structure, or characteristic described in
connection with an
embodiment is included in at least one embodiment. Thus, the appearance of the
phrases "in
one embodiment" or "in an embodiment" in various places throughout the
specification is not
necessarily referring to the same embodiment. Further, the particular
features, structures or
characteristics may be combined in any suitable manner in one or more
embodiments.
[0014] As used herein, the term "nonmetallic iodide" is meant to include any
nonmetallic
compound, incorporating, or otherwise capable of providing or forming in a
reaction mixture,
at least one hypervalent iodine species. Similarly, the term "inorganic iodine
salt" is meant to
include inorganic salt, incorporating, or otherwise capable of providing or
forming in a
reaction mixture, at least one hypervalent iodine species. The term
"hypervalent", in turn,
and as is understood by those of ordinary skill in the chemical arts, means a
compound that
may typically have one or more elements bearing more than eight electrons in
their valence
shells, and in particular iodine sources having oxidation states of greater
than or equal to +1,
e.g., +1, +3, +5, +7, etc. A precursor is a compound or composition that
provides the active
catalytic species in situ, for example, iron metal can form ferric chloride in
environments
comprising chlorine.
[0015] "PDC" may be used herein as an abbreviation for 1,2-dichloropropane,
"TCP" may
be used as an abbreviation for 1,2,3-trichloropropane and "TCPE" may be used
as an
abbreviation for 1,1,2,3-tetrachloropropene.
[0016] The present
invention provides efficient processes for the production of chlorinated
propanes and/or propenes. The present processes advantageously make use of a
starting
feedstream comprising 1,2-dichloropropane. PDC is readily available at low
cost, at least
because it is a by-product in many chlorohydrin processes. Conventionally, it
is disposed of,
typically via incineration, and so, using it as a starting material presents
an opportunity to
make use of an otherwise wasted material.
4
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
[0017] Further, in
at least one chlorination step of the process, a catalyst that provides a
regioselectivity of at least 5:1, or 8:1, or 10:1, or 15:1, or 20:1, or 30:1
or 40:1, or even 50:1,
or greater, to one chloropropane relative to other chloropropane isomers
having the same
number of chlorine atoms is utilized. In some
embodiments, for example, 1,1,2-
trichloropropanc may be provided at a regioselectivity of at least 20:1,
relative to other
trichloropropane isomers. In other embodiments, 1,1,2,2,3-pentachloropropane
may be
provided at a regioselectivity of at least 20:1 relative to other
pentachloropropane isomers.
[0018] This high
degree of selectivity is desirable in chloropropane intermediates, since
production of predominantly desired intermediates can lead to regioselectivity
to the desired
chlorinated propene, which in some embodiments, may be 1,1,2,3-
tetrachloropropene.
Further, this high degree of regioselectivity has previously been provided
only via extreme
reaction conditions, e.g., high temperatures, e.g., greater than 100 C, high
pressures, i.e., 100
psi over ambient and higher, and/or the use of vapor phase reactions. Such
conditions may be
undesirable not only because of the cost associated with the same, but also
because they can
result in reactor fouling due to product decomposition.
[0019] In contrast,
the present processes utilize temperatures of less than 100 C or less
than 90 C, or less than 80 C, or less than 75 C, or less than 70 C, or even
less than 65 C, or
60 C. Ambient pressures or pressures of at least 100 psi greater than ambient
may be
utilized. And, one or more reactions may be conducted in the liquid phase, so
that
evaporation of the reactants is not required, and thus reactor fouling may be
minimized.
[0020] In some
embodiments, a Lewis acid catalyst may be utilized to provide the desired
regioselectivity to the chloropropane intermediate. In such embodiments, the
Lewis acid
catalyst may be utilized alone, and yet provide the desired regioselectivity
to, e.g., 1,1,2-
trichloropropane, particularly with 1,2-dichloropropane present in the
feedstream.
[0021] Examples of
Lewis acids capable of providing the recited regioselectivity include,
but are not limited to, ferric chloride, antimony pentafluoride, boron
trichloride, aluminum
chloride and/or trichloride, and stannic chloride. Precursors to these, as
well as any active
decomposition products, may also be used. Combinations of two or more of these
may also
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
bc used, if desired. In some embodiments, anhydrous aluminum chloride may
desirably be
utilized as the at least one Lewis acid.
[0022] In other
embodiments, the regioselective catalyst may comprise iodine, and more
specifically, may comprise a nonmetallic iodide and/or an inorganic iodine
salt. While
conventional processes that employ nonmetallic iodides are taught to be
limited to the
addition of single chlorine atoms, it has now been discovered that,
nonmetallic iodides not
only can add multiple chlorine atoms, but further, are capable of adding
multiple chlorine
atoms in a highly regioselective manner. Additionally, as a further indication
of their
catalytic action, little or no iodoalkane byproducts are produced when
nonmetallic iodides are
used as chlorination catalysts.
[0023] Any
nonmetallic iodide can be used in the mixed catalyst system, and those of
ordinary skill in the art are expected to be familiar with many. Suitable
examples include, but
are not limited to, iodobenzene, halogenated iodobenzenes,
phenylchloroiodonium chloride,
diaryliodonium salts, iodinated polymers, iodoxy compounds, iodoso compounds,
iodine
mono- and trihalides, iodine oxides, and derivatives or combinations of any
number of these.
[0024] In other
embodiments, one or more inorganic iodine salts may be utilized as the
regioselective catalyst. Advantageously, in those embodiments wherein the
process is
conducted in a nonageuous media, the one or more inorganic iodine salts may be
recovered in
whole or in part, and/or reused.
[0025] Any
inorganic iodine salt can be used as the regioselective catalyst, and those of
ordinary skill in the art are expected to be familiar with many. Suitable
examples include, but
are not limited to, hypoiodites iodites (I09-), iodates (I03-), and/or
periodates
including mesoperiodates and orthoperiodates, or combinations of these.
Specific examples
of inorganic iodine salts include, but are not limited to sodium iodate,
silver iodate, calcium
iodate, potassium iodate, iodic acid, sodium periodate, potassium periodate,
barium
periodate, and periodic acid, and derivatives or combinations of any number of
these.
[0026] In other
embodiments, elemental iodine may be used, but at levels much lower
than previously thought to be effective. That is, it has now been discovered
that amounts of
iodine much lower than conventionally utilized, i.e., 0.01 wt.%, provide
improvements in
6
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
yield and selectivity while yet not presenting the corrosion and volatility
issues that may arise
when these conventional levels are utilized. More specifically, amounts of
elemental iodine
of from 1 ppm to 5000 ppm, or from 5 ppm to 1000 ppm, or from 10 ppm to 100
ppm, have
now surprisingly been discovered to provide selectivities to the desired
chlorinated propanes
and/or propenes of greater than 60%, in some cases greater than 70%, and in
some cases
greater than 80%. This is a significant improvement over processes wherein no
iodine is used
at all, wherein conversions of e.g., less than 60% can be seen. Since
elemental iodine can be
costly, significant cost savings are also provided by using the smaller
amounts described
herein. Combinations of one or more nonmetallic iodides, inorganic iodine
salts and
elemental iodine may also be used.
[0027] At least one
regioselective catalysts is desirably used in the present process.
Further, the at least one regioselective catalyst may be used in each
chlorination step of the
process, or in only one chlorination step, or any number of steps in between.
All that is
required is that at least one regioselective catalyst, i.e., the Lewis acid,
nonmetallic iodide,
inorganic iodide salt, and/or less than 10,000 ppm elemental iodine be
employed in at least
one chlorination step of the process.
[0028] In some
embodiments, two or more of the regioselective catalysts may be utilized
in the present process, either together as a mixed catalyst system, or
consecutively. As is the
case when one regioselective catalyst is used, the two or more regioselective
catalysts may be
utilized in one chlorination step of the process, two chlorination steps of
the process, etc., or
all chlorination steps of the process. For example, a Lewis acid may be used
to catalyze the
production of 1,1,2-trichloropropane from 1,2-dichloropropane, and then an
iodine catalyst,
i.e., a nonmetallic iodide, inorganic iodine salt, or less than 10,000ppm
elemental iodine, used
to catalyze the production of 1,1,2,2,3-pentachloropropane thereafter. In such
embodiments,
both, or all, regioselective catalysts may be present in the reactor
initially, or, added
sequentially thereto.
[0029] If desired,
some chlorination steps of the process may be carried out in the
presence of conventional ionic chlorination catalysts or free radical
initiators. Conventional
ionic chlorination catalysts that may be used in the present process are known
to those of
ordinary skill in the art, and any of these may be used. Exemplary ionic
chlorination catalysts
7
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
include, but are not limited to, compounds comprising iron (ferric chloride),
chlorine and
sulfur, etc. If conventional ionic chlorination catalysts are to be utilized
in one or more of the
chlorination steps of the present process, the use of aluminum chloride can be
preferred.
[0030] Suitable
free radical chlorination catalysts include, but are not limited to,
compounds comprising one or more azo-groups (R-N=N-R') such as
azobisisobutyronitrile
(AIBN) or 1,1'-azobis(cyclohexanecarbonitrile) (ABCN) and organic peroxides
such as di-
tert-butyl peroxide, dibenzoyl peroxide, benzoyl peroxide, methyl ethyl ketone
peroxide, and
acetone peroxide. In some embodiments, the use of benzoyl peroxide may be
preferred,
either alone or in combination with UV or visible light or heat. Such
catalysts may also
enhance the chlorination of double bonds in olefins or chlorinated olefins to
produce a, 13
dichloroalkanes.
[0031] The
chlorinated propanes produced via the chlorination step(s) can be converted to
propenes in any known fashion, such as via one or more dehydrochlorination
reactions or
steps. Any such dehydrochlorination steps may be conducted in the presence of
an inorganic
base such as a liquid phase caustic. Many chemical bases are known in the art
to be useful
for this purpose, and any of these can be used. For example, suitable bases
for
dehydrochlorination include, but are not limited to, alkali metal hydroxides,
such as sodium
hydroxide, potassium hydroxide, calcium hydroxide; alkali metal carbonates
such as sodium
carbonate; lithium, rubidium, and cesium or combinations of these. Phase
transfer catalysts
such as quaternary ammonium and quaternary phosphonium salts can also be added
to
improve the dehydrochlorination reaction rate with these chemical bases.
[0032]
Alternatively, in some embodiments, one or more dehydrochlorination steps
utilized in the process may be carried out in the presence of a catalyst so
that the reaction rate
is enhanced and also use of liquid caustic is reduced, or even eliminated,
from the process. If
the use of catalysts is desired, suitable dehydrochlorination catalysts
include, but are not
limited to ferric chloride (FeCl3) and aluminum chloride (A1C13). Ferric
chloride, for
example, can be used to dehydrochlorinate 1,1,1,2,3-pentachloropropane to
TCPE.
8
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
[0033] Any or all
of the chlorination and/or dehydrochlorination catalysts can be provided
either in bulk or in connection with a substrate, such as activated carbon,
graphite, silica,
alumina, zeolites, fluorinated graphite and fluorinated alumina.
[0034] Generally
speaking, and whatever the regioselective catalyst, other chlorination
catalyst or dehydrochlorination catalyst(s) employed, enough of the catalyst
should be
utilized to provide some improvement to reaction process conditions (e.g., a
reduction in
required temperature) and desirably, reaction selectivity, but yet not be more
than will
provide any additional benefit, if only for reasons of economic practicality.
[0035] For purposes
of illustration only, then, it is expected that useful concentrations of a
regioselective catalyst comprising a Lewis acid, in a batch process, will
range from 0.001%
to 20% by weight each with respect to dichloropropane, or from 0.01% to 10%,
or from 0.1%
to 5 wt.%, inclusive of all subranges therebetween. Suitable batch process
concentrations of
a regioselective catalyst comprising a nonmetallic iodide are expected to
range from 0.001%
to 80% by weight with respect to the dichloropropane, or from 0.01% to 60%, or
from 0.1%
to 40 wt.%, inclusive of all subranges therebetween. Useful
concentrations of a
regioselective catalyst comprising an inorganic iodine salt, in a batch
process, will range from
0.001% to 40% by weight with respect to the alkane, or from 0.01% to 30%, or
from 0.1% to
20 wt.%, inclusive of all subranges therebetween. Surprisingly low levels of
elemental iodine
are effective, e.g., from 1 ppm to 5000 ppm, or from 5 ppm to 1000 ppm, or
from 10 ppm to
100 ppm.
[0036] If a
dehydrochlorination catalyst, e.g., FeC13, is utilized, useful concentrations
may
range from 0.01wt% to 5wt.%, or from 0.05wt% to 2wt% at temperature of 70 C to
200 C. If
a chemical base is utilized for one or more dehydrochlorinations, useful
concentrations of
these will range from 0.01 to 20 grmole/L, or from 1 grmole/L to 10 grmole/L,
inclusive of
all subranges therebetween.
[0037] Chlorine
atoms are desirably supplied to the process by either chlorine, sulfuryl
chloride, or both. In the case of embodiments wherein sulfuryl chloride
(S02C12) is utilized
as a chlorine source, advantages can be seen in that sulfuryl chloride can
also act as a solvent
for the regioselective catalysts and/or reactions, thereby assisting in the
provision of an
9
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
acceptable reaction rate and/or yield. And, the sulfuryl chloride may be
regenerated, if
desired. On the other hand, in those embodiments wherein regeneration of
sulfuryl chloride
may prove unwieldy or otherwise be undesirable, chlorine may utilized, either
alone or in
conjunction with an appropriate solvent, such as, e.g., carbon tetrachloride
and/or 1,2,3-
trichloropropanc. In such embodiments, lesser concentrations of the chlorine
source can be
required, at least since chlorine is not also acting as a solvent. Further,
the regioselective
catalyst may retain its activity for a longer period of time in those
embodiments wherein
chlorine gas is used as the chlorine source as opposed to sulfuryl chloride.
[0038] The reaction
conditions under which the process is carried out are advantageously
low intensity. That is, low temperatures, e.g., of less than 100 C, or less
than 90 C, or less
than 80 C or less than 70 C, or less than 60 C, may be utilized and the
desired selectivities to
the desired chlorinated alkenes yet be realized. In some embodiments,
temperatures of from
40 C to 90 C, or from 50 C to 80 C, or from 55 C to 75 C, may be utilized.
Similarly,
ambient pressure is suitable for carrying out the process, or pressures within
300, or 200, or
100, or 50, or 40, or 30, or 20, or even 10 psi, of ambient are suitable.
Reactor residence time
may also be minimized with the desired selectivities yet seen ¨ for example,
reactor
occupancy times of less than 15 hours, or less than 10 hours, or less than 9,
8, 7, 6, or even 5
hours, are possible. The reactor may be any suitable liquid phase reactor,
such as a batch or
continuous stirred tank autoclave reactor with an internal cooling coil. A
shell and multitube
exchanger followed by vapor liquid disengagement tank or vessel can also be
used.
[0039] That being
said, the particular conditions employed at each step described herein
are not critical, nor is the sequence of reaction steps, and these are readily
determined by
those of ordinary skill in the art. Those of ordinary skill in the art will
readily be able to
determine the particular conditions at which to operate the
distillation/fractionation, drying,
dehydrochlorination and isomerization steps described herein, as well as the
appropriate order
of the steps to arrive at the desired chlorinated propene. What is important
is that PDC is
utilized as a starting material, and at least one chlorination step is
conducted in the presence
of one or more catalysts that provide a regioselectivity to one chloropropane
of at least 5:1
relative to other chloropropanes. In some embodiments, provisions may also be
made for the
recovery of anhydrous HC1.
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
[0040] In the
present process, dichloropropane is converted to a chlorinated alkenc, e.g.,
TCPE, using a series of consecutive chlorination and dehydrochlorination
steps. In one
exemplary embodiment, PDC is fed to a liquid phase chlorination reactor, e.g.,
such as a
batch or continuous stirred tank autoclave reactor with an internal cooling
coil. A shell and
multitubc exchanger operating in plug flow, followed by vapor liquid
disengagement tank or
vessel can also be used. Suitable reaction conditions include, e.g., a
temperature of from
30 C to 150 C, a pressure of from 100 kPa to 2000kPa. The reaction is carried
out in the
presence of one or more regioselective catalysts that provide a
regioselectivity to, e.g., 1,1,2-
trichloropropane of at least 5:1 over other trichloropropane isomers.
[0041] Some
embodiments of the invention will now be described in detail in the
following examples.
[0042] Example J. Ionic Chlorination of PDC to trichloropropanes using
aluminum
chloride as regioselective catalyst and sulfuryl chloride as chlorinating
agent.
[0043] Liquid
sulfuryl chloride and PDC (1,2-dichloropropane) are mixed in a 100m1
flask heated in a water bath to maintain temperature 55 C-60 C in the presence
of 40 mo10/0
of A1C13. A reflux column is placed to return unreacted reactants as well the
reaction
intermediate 1-chloropropene to the reaction liquid while the HC1 and SO2
byproducts are
released to a caustic scrubber at the top of the reflux column. Gas
chromatography coupled
with mass spectrometry is used to determine the product composition.
[0044] After 30
minutes of reaction time the product mixture was found to be 1,1,2-
trichloropropane and 1,2,3-trichloropropane at molar ratio of 40 to 1.
[0045] Example 2. Ionic Chlorination of 1,2-dichloropropane to 1,1,2,2,3-
pentachloropropane using aluminum chloride as regioselective catalyst and
sulfuryl chloride
as chlorinating agent.
[0046] Liquid
sulfuryl chloride and 1,2-dichloropropane are mixed in a 100m1 flask
heated in a water bath to maintain temperature 55 C-60 C in the presence of 40
mole% A1C13
catalyst. A reflux column is placed to return unreacted reactants as well the
reaction
intermediates to the reaction liquid while the HC1 and SO2 byproducts are
released to a
11
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
caustic scrubber at the top of the reflux column. Gas chromatography coupled
with mass
spectrometry is used to determine the product composition.
[0047] After 17
hours of reaction time the product mixture was found to contain 1,1,2,2,3-
pcntachloropropane as the only pentachloropropane.
[0048] Example 3.
Chlorination of 1,1,2-trichloropropane to 1,1,2,2,3-pentachloropropane
using iodobenzene and aluminum chloride as regioselective catalyst and
sulfuryl chloride as
chlorinating agent.
[0049] A product
stream containing 26wt% 1,1,2-trichloropropane, 61wt% sulfuryl
chloride, and 12wt% aluminum chloride based upon the total weight of the
initial reaction
mixture is charged with 10 mole % aluminum chloride dissolved in 310 mole ')/0
sulfuryl
chloride followed by 10 mole % iodobenzene wherein the mole% are with respect
to 1,1,2-
trichloropropane. The resulting mixture is stirred for 4 hours at a
temperature of 70 C and
then cooled to ambient temperature prior to pouring the mixture into an ice
bath. The
resulting solution is filtered to remove the quenched catalyst byproduct and
the resulting
product mixture is analyzed by gas chromatography. The final organic phase is
found to
consist of >91% 1,1,2,2,3-pentachloropropane, with the remaining 9% comprising
a mixture
of tri-,tetra-, and hexachloropropane isomers.
[0050] Example 4.
Chlorination of 1,1,2-trichloropropane to 1,1,2,2,3-pentachloropropane
using iododurene (23,5,6-tetramethy1-1-iodobenzene) and aluminum chloride as
regioselective catalysts and sulfuryl chloride as chlorinating agent.
[0051] A product
stream containing 26wt% 1,1,2-trichloropropane, 61wt% sulfuryl
chloride, and 12wt% aluminum chloride based upon the total weight of the
initial reaction
mixture is charged with 10 mole % aluminum chloride dissolved in 200 mole %
sulfuryl
chloride followed by 10 mole % iododurene, wherein all mole %s are with
respect to 1,1,2-
trichloropropane. The resulting mixture is allowed to stir for 3 hours at a
temperature of 70 C
and then cooled to ambient temperature prior to pouring the mixture into an
ice bath. The
resulting solution is filtered to remove the quenched catalyst byproduct and
the resulting
product mixture is analyzed by gas chromatography. The final organic phase is
found to
12
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
consist of >84% 1,1,2,2,3-pentachloropropane, with the remaining 16%
comprising a mixture
of tri-,tetra-, and hexa-chloropropane isomers.
[0052] Example 5.
Chlorination of 1 ,2-dichloropropane to 1,1,2,2,3 -pentachl oroprop an e
using sodium periodate and aluminum chloride as regioselective catalysts and
sulfuryl
chloride as chlorinating agent.
[0053] 17g sulfuryl
chloride and 2.5g aluminum chloride is charged to a reactor equipped
with a magnetic stir bar and reflux condenser. The reaction mixture is heated
to 60 C and
then 4.1g of 1,2-dichloropropane is charged. The reaction is stirred for 35
minutes, where
GC analysis indicated that >99% of the 1,2-dichloropropane had been reacted to
form
primarily 1,1,2-trichloropropane.
[0054] An
additional 15g of sulfuryl chloride along with 1g of sodium periodate is
added.
The reaction is allowed to react for a total 4 hours before being cooled back
to ambient
temperature. The crude reaction mixture is filtered to collect the sodium
periodate catalyst as
a wet cake that is washed with methylene chloride to give 0.8g of recovered
sodium
periodate.
[0055] The reaction
mixture and methylene chloride wash are combined, slowly poured
into an ice water bath, and allowed to stir until quenched. The organic and
aqueous phases are
separated and the aqueous phase is extracted with an equal volume of methylene
chloride.
The combined organic fractions are dried over magnesium sulfate, the excess
solvent is
removed by rotary evaporator, and the final product is isolated as a colored
oil.
[0056] GC and NMR
analysis of the final product mixture shows a yield of 4.7g of
1,1,2,2,3-pentachloropropane, 0.7g of tetrachloropropane isomers, 0.4g of
1,1,2-
trichloropropane, 0.3g of hexachloropropane isomers, and 0.2g of 1,2,3-
trichloropropane.
[0057] Example 6.
Chlorination of 1,2-dichloropropane to 1,1,2,2,3-pentachloropropane
using aluminum chloride and recovered sodium periodate as regioselective
catalysts and
sulfuryl chloride as chlorinating agent.
[0058] 9.3g
sulfuryl chloride and 1.3g aluminum chloride is charged to a reactor equipped
with a magnetic stir bar and reflux condenser. The reaction mixture is heated
to 60 C and
13
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
charged with 2.3g of 1,2-dichloropropane. The reaction is stirred for 35
minutes, when GC
analysis indicates that >99% of the 1,2-dichloropropane has reacted to form
primarily 1,1,2-
trichloropropane.
[0059] An
additional 7.9g of sulfuryl chloride along with 0.5g of sodium periodate
recovered from Example 5is charged. The reaction is allowed to react for a
total of 4 hours
before being cooled back to ambient temperature. The crude reaction mixture is
filtered to
collect the sodium periodate catalyst as a wet cake that is washed with
methylene chloride to
give 0.45g of recovered sodium periodate.
[0060] The reaction
mixture and methylene chloride wash are combined, slowly poured
into an ice water bath, and allowed to stir until quenched. The organic and
aqueous phases
are separated and the aqueous phase is extracted with an equal volume of
methylene chloride.
The combined organic fractions are dried over magnesium sulfate, the excess
solvent is
removed by rotary evaporator, and the final product is isolated as a colored
oil.
[0061] GC and NMR
analysis of the final product mixture shows a yield of 3.1g of
1,1,2,2,3-pentachloropropane, 0.5g of hexachloropropane isomers, 0.1g of 1,2,3-
trichloropropane, and 0.1g of tetrachloropropane isomers.
[0062] Example 7.
Chlorination of 1,2-dichloropropane to 1,1,2,2,3-pentachloropropane
using sodium iodate and aluminum chloride as regioselective catalysts and
sulfuryl chloride
as chlorinating agent.
[0063] 17g sulfuryl
chloride and 2.5g aluminum chloride is charged to a reactor equipped
with a magnetic stir bar and reflux condenser. The reaction mixture is heated
to 60 C and
then 4.1g of 1,2-dichloropropane is charged. The reaction is allowed to stir
for 35 minutes,
when GC analysis indicates that >99% of the 1,2-dichloropropane has reacted to
form
primarily 1,1,2-trichloropropane.
[0064] An
additional 15g of sulfuryl chloride along with 0.5g of sodium iodate is
charged.
The reaction is allowed to react for a total 4 hours before being cooled back
to ambient
temperature. The reaction mixture is slowly poured into an ice water bath and
allowed to stir
until quenched. The organic and aqueous phases are separated and the aqueous
phase is
14
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
extracted with an equal volume of methylene chloride. The sodium iodate is
recovered in the
aqueous wash as indicated by ion chromatography analysis. The combined organic
fractions
are dried over magnesium sulfate, the excess solvent is removed by rotary
evaporator, and the
final product was isolated as a colored oil.
[0065] GC and NMR
analysis of the final product mixture shows a yield of 5.4g of
1,1,2,2,3-pentachloropropane, 0.6g of tetrachloropropane isomers, 0.4g of
hexachloropropane
isomers, 0.3g of 1,1,2-trichloropropane and 0.2g of 1,2,3-trichloropropane.
[0066] Example 8.
Chlorination of 1,2-dichloropropane to 1,1,2,2,3-pentachloropropane
using sodium iodate and aluminum chloride as regioselective catalysts and
sulfuryl chloride
as chlorinating agent.
[0067] 17g sulfuryl
chloride, 0.6g aluminum chloride, and 0.8g of sodium iodate is
charged to a reactor equipped with a magnetic stir bar and reflux condenser.
The reaction
mixture is heated to 60 C and then 4.1g of 1,2-dichloropropane is added. The
reaction is
allowed to stir for a total 4 hours before being cooled back to ambient
temperature.
[0068] The reaction
mixture is slowly poured into an ice water bath and allowed to stir
until quenched. The organic and aqueous phases are separated and the aqueous
phase is
extracted with an equal volume of methylene chloride. The sodium iodate is
recovered in the
aqueous wash as indicated by ion chromatography analysis. The combined organic
fractions
are dried over magnesium sulfate, the excess solvent is removed by rotary
evaporator, and the
final product is isolated as a colored oil.
[0069] GC and NMR
analysis of the final product mixture shows a yield of 2.3g of
1,1,2,2,3-pentachloropropane, 1.4g of 1,1,2-trichloropropane, 0.9g of
tetrachloropropane
isomers, 0.8g of 1,2,3-trichloropropane, and 0.2g of hexachloropropane
isomers.
[0070] Example 9.
Chlorination of 1,2-dichloropropane to 1,1,2,2,3-pentachloropropane
using aluminum chloride as regioselective catalyst and chlorine as
chlorinating agent.
1,2-dichloropropane (10 mL) is added to a solution of carbon tetrachloride
(37.2 mL)
containing aluminum trichloride (0.51 g). The mixture is stirred while
chlorine (30% v/v in
nitrogen) is passed through the solution while the mixture is held at 50 C for
3 hr and then at
CA 02859168 2019-06-12
WO 2013/090421
PCT/US2012/069230
100 C for 1 hr. The pressure of the system was maintained between 60-100 psig
throughout
the reaction. Analysis of the reaction mixture via 1H NMR spectroscopy
revealed that 1,2-
dichloropropane was nearly consumed within 3hr at 50 C producing 1,1,2-
trichloropropane
as the major product. After additional 1 hr and 100 C, the analysis of the
final mixture
identified 1,1,2,2,3-pentachloropropane as the major product.
[0071] Example 10.
Chlorination of 1,2-dichloropropane to 1,1,2,2,3-pentachloropropane
using aluminum chloride and low levels of elemental iodine as regioselective
catalysts and
chlorine as chlorinating agent.
[0072] A product
stream is prepared by feeding chlorine gas at 30 seem through a starting
mixture of 22.6wt% 1,2-dichloropropane, 1.3wt% aluminum chloride, and 76.1wt%
methylene chloride at 130psig and 70 C until GC analysis indicates that the
starting
dichloropropane has undergone 68% conversion to give 1,1,2-trichloropropane as
the major
intermediate species. This stream is charged with 35ppm elemental iodine
dissolved in 15mL
of methylene chloride based on initial dichloropropane within the reaction
mixture. The
resulting mixture is allowed to stir until 36.1% conversion of the 1,1,2-
trichloropropane
intermediate is observed to give the desired pentachloropropane as the major
isomer.
Furthermore, the desired pentachloropropane and its precursor 1,2,2,3-
tetrachloropropane in
82.3% selectivity over the undesired byproducts of 1,1,2,2,3,3-
hexachloropropane and
1,1,2,3 -tetrachloropropane.
16
