U.S. patent application number 11/102620 was filed with the patent office on 2006-04-13 for process for exchanging anions in phenothiazinium derivatives.
This patent application is currently assigned to Honeywell International Inc.. Invention is credited to Andreas Kanschik-Conradsen, Thomas Potrawa, Joachim Schulz, Suzanne Wassman-Wilken, Christian Werner, Jorg Wilken.
Application Number | 20060079681 11/102620 |
Document ID | / |
Family ID | 35539701 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060079681 |
Kind Code |
A1 |
Wassman-Wilken; Suzanne ; et
al. |
April 13, 2006 |
Process for exchanging anions in phenothiazinium derivatives
Abstract
A process for producing a phenothiazinium compound comprising
the step of: reacting phenothiazine, in the presence of a halogen,
with at least one amine selected from the group consisting of:
##STR1## wherein Z is CH.sub.2, O, S, SO.sub.2, NH, NCH.sub.3,
NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or NCOCH.sub.3, and R.sup.1
and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY; and replacing the halogen with a non-halide
counteranion.
Inventors: |
Wassman-Wilken; Suzanne;
(Hannover, DE) ; Potrawa; Thomas; (Seelze, DE)
; Kanschik-Conradsen; Andreas; (Garbsen, DE) ;
Werner; Christian; (Hannover, DE) ; Schulz;
Joachim; (Pohle, DE) ; Wilken; Jorg;
(Hannover, DE) |
Correspondence
Address: |
Honeywell International Inc.;Patent Services Department
101 Columbia Road
Morristown
NJ
07962
US
|
Assignee: |
Honeywell International
Inc.
|
Family ID: |
35539701 |
Appl. No.: |
11/102620 |
Filed: |
April 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10960811 |
Oct 7, 2004 |
|
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11102620 |
Apr 8, 2005 |
|
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Current U.S.
Class: |
540/599 ; 544/37;
544/42 |
Current CPC
Class: |
C07D 279/28 20130101;
C07D 279/18 20130101 |
Class at
Publication: |
540/599 ;
544/037; 544/042 |
International
Class: |
C07D 417/02 20060101
C07D417/02; C07D 279/18 20060101 C07D279/18 |
Claims
1. A process for producing a phenothiazinium compound comprising
the step of: reacting phenothiazine, in the presence of a halogen,
with at least one amine selected from the group consisting of:
##STR15## wherein Z is CH.sub.2, O, S, SO.sub.2, NH, NCH.sub.3,
NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or NCOCH.sub.3, and R.sup.1
and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY, and wherein said phenothiazinium compound has the
general formula: ##STR16## wherein A and B are each selected from
the group consisting of: ##STR17## wherein Z is CH.sub.2, O, S,
SO.sub.2, NH, NCH.sub.3, NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or
NCOCH.sub.3 and R.sup.1 and R.sup.2 are each independently linear
or branched C.sub.nH.sub.2nY, where n is 1-6, Y is H, F, Br, I, OH,
OCH.sub.3, OC.sub.2H.sub.5, OC.sub.3H.sub.7, CN or OCOCH.sub.3, and
where X.sup.- is a halide counteranion; and replacing said halide
counteranion with a non-halide counteranion.
2. The process according to claim 1, wherein said non-halide
counteranion is at least one selected from the group consisting of:
mono- or di-carboxylic acid anions having a carbon chain length of
between about 1 to 6, hydrogensulfate, sulfate, phosphate,
hydrogenphosphate, dihydrogenphosphate, cyanate, nitrate, sulfide,
and other anions derived from non-organic acids.
3. The process according to claim 1, wherein said step of replacing
said halide counteranion is at least one process selected from the
group consisting of: (a) exchanging said halide counteranion with
said non-halide counteranion via an ion exchange resin; (b) forming
an acid of said halide counteranion and thereafter adding a
stronger acid than said acid of said halide counteranion to thereby
drive said weaker acid or said halide counteranion out of said
phenothiazinium compound; (c) forming an acid of said halide
counteranion and driving said acid of said halide counteranion out
of said phenothiazinium compound using oxidation to remove the
evolving HX as X.sub.2; and (d) introducing a non-halide
counteranion salt to a salt of said halide counteranion containing
phenothiazine mixture, and separating and removing said halide
counteranion, wherein a non-halide counteranion salt of
phenothiazine produced.
4. The process according to claim 1, wherein said step of replacing
said halide counteranion comprises: forming a less soluble
hydroxide salt of said halide counteranion; and adding an acid of
said non-halide counteranion to said hydroxide salt.
5. The process according to claim 1, wherein said halogen is
selected from the group consisting of: bromine, iodine, chlorine
and mixtures thereof.
6. The process according to claim 1, wherein said amine is a
dialkylamine selected from the group consisting of:
diisoalkylamine, di-n-alkylamine and n-alkyl-iso-alkyl-amine.
7. The process according to claim 6, wherein said dialkylamine is
selected from the group consisting of: diisopropylamine,
diisobutylamine, diisopentylamine, di-n-propylamine,
di-n-butylamine, di-n-pentylamine, ethyl-isopropylamine and
mixtures thereof.
8. The process according to claim 1, wherein said reaction occurs
at a temperature in the range between about -5.degree. C. to
55.degree. C.
9. The process according to claim 1, wherein said phenothiazine has
the formula: ##STR18##
10. The process according to claim 1, further comprising: filtering
said phenothiazinium compound.
11. The process according to claim 1, wherein said reaction is
carried out in a single reactor.
12. The process according to claim 11, wherein said phenothiazine
and said amine are mixed together, followed by addition of said
halogen.
13. The process according to claim 8, wherein said reaction occurs
at a temperature in the range between about -5.degree. C. to
20.degree. C.
14. The process according to claim 8, wherein said reaction occurs
at a temperature in the range between about 50.degree. C. to
55.degree. C.
15. A process for producing a phenothiazinium compound comprising
the step of: reacting phenothiazine, in the presence of a bromine,
with at least one dialkylamine; and replacing said bromine with a
non-halide counteranion.
16. The process according to claim 15, wherein said non-halide
counteranion is at least one selected from the group consisting of
mono- or di-carboxylic acid anions having a carbon chain length of
between about 1 to 6, hydrogensulfate, sulfate, phosphate,
hydrogenphosphate, dihydrogenphosphate, cyanate, nitrate, sulfide,
and other anions derived from non-organic acids.
17. The process according to claim 15, wherein said step of
replacing said bromine is at least one process selected from the
group consisting of: (a) exchanging said bromine with said
non-halide counteranion via an ion exchange resin; (b) forming an
acid of said bromine and thereafter adding a stronger acid than
said acid of said bromine to thereby drive said weaker acid or said
bromine out of said phenothiazinium compound; (c) forming an acid
of said bromine and driving said acid of said bromine out of said
phenothiazinium compound using oxidation to remove the evolving HX
as X.sub.2; and (d) introducing a non-halide counteranion salt to a
salt of said bromine containing phenothiazine mixture, and
separating and removing said bromine, wherein a non-halide
counteranion salt of phenothiazine produced.
18. The process according to claim 15, wherein said step of
replacing said bromine comprises: forming a less soluble hydroxide
salt of said bromine; and adding an acid of said non-halide
counteranion to said hydroxide salt.
19. The process according to claim 15, wherein said phenothiazinium
compound has the general formula: ##STR19## wherein A and B are
each selected from the group consisting of: ##STR20## wherein
R.sup.1 and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY, n is 1 to 6, and where X.sup.- is a bromide
counteranion.
20. The process according to claim 15, wherein said dialkylamine is
selected from the group consisting of: diisopropylamine,
diisobutylamine, diisopentylamine, di-n-propylamine,
di-n-butylamine, di-n-pentylamine, ethyl-isopropylamine and
mixtures thereof.
21. The process according to claim 15, wherein said dialkylamine is
di-n-propylamine.
22. The process according to claim 15, wherein said dialkylamine is
di-n-butylamine.
23. The process according to claim 15, wherein the bromination
takes place in the presence of an alcohol.
24. The process according to claim 15, wherein said reaction occurs
at a temperature in the range between about -5.degree. C. to
55.degree. C.
25. The process according to claim 15, wherein said phenothiazine
has the formula: ##STR21##
Description
RELATED APPLICATIONS
[0001] This is a Continuation-in-Part Application of U.S. patent
application Ser. No. 10/960,811, filed on Oct. 7, 2004, which is
incorporated in its entirety herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a novel process
for exchanging anions in phenothiazinium derivatives.
[0004] 2. Discussion of the Background Art
[0005] There has been recent advances in the use of compounds
having a photosensitizing chromophoric system, a sulphonamido
functionality and a carboxy functionality as a photosensitizer in
photodynamic therapy (PDT), in photochemical internalization in the
production of a cancer vaccine or in the diagnosis or detection of
medical conditions.
[0006] These photosensitizing chromophoric systems are preferably
residue of a metal-free phthalocyanine, a methyl phthalocyanine, a
benzoporphyrin, a purpurin, a chlorin, a bacteriochlorin, a
tetraarylporphyrin, a porphycene or a texaphyrin, more preferably a
residue of a metal phthalocyanine, a chlorin or a bacteriochlorin,
especially a residue of a metal phthalocyanine, as set forth in
US-2003/0180224, which is incorporated herein in its entirety.
[0007] Such phenothiazinium compounds are disclosed in WO-02/096896
as comprising the following formula (I): ##STR2## wherein A and B
are each independently selected from the group consisting of:
##STR3## wherein Z is CH.sub.2, O, S, SO.sub.2, NH, NCH.sub.3,
HC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or HCOCH.sub.3 and R.sup.1 and
R.sup.2 are each independently linear or branched C.sub.nH.sub.2nY,
where n is 1-6, Y is H, F, Cl, Br, I, OH, OCH.sub.3,
OC.sub.2H.sub.5, OC.sub.3H.sub.7, CN or OCOCH.sub.3, and where
X.sup.p- is a counteranion and P is 1, 2 or 3.
[0008] Unfortunately, WO-02/096896 does not teach a commercially
acceptable synthesis route for the manufacture of such
phenothiazinium compounds, or any synthesis route for that
matter.
[0009] K. J. Mellish et al. (Photochem. Photobiol., 2002, 75/4,
392-397) describes the synthesis of a series of
tetraalkyl-iodide-derivatives of phenothiazine by an elaborate
procedure. The phenothiazine is halogenated first and isolated, and
then reacted at room temperature with the appropriate
N,N-dialkylamine. The compounds are isolated by an elaborated
work-up procedure using, e.g., halogenated solvents and only
characterized by mass spectrometry. The purity cannot be derived
from the data given.
[0010] N. Leventis et al. (Tetrahedron, 1997, 53/29, 10083-10092)
describes the synthesis of a series of thiazine dyes. The synthesis
is performed in two steps by halogenating phenothiazine in glacial
acetic acid and then reaction with the corresponding amine in
ethanol. The last step requires work up with chloroform and then
isolation by column chromatography using chloroform/MeOH. The
evaporation of the organic fractions is followed by
recrystallization. This extensive procedure is not practicable for
a large-scale synthesis.
[0011] L. Strekowski et al. (J. Heterocycl. Chem. 1993, 30/4,
1693-1695) describes the synthesis of
dialkylamino-phenothiazin-derivatives with two different amino
groups and I.sub.3.sup.- as the counterion. The compounds are
synthesized in a two-step synthesis.
[0012] K. W. Loach (J. Chrom., 1971, 60, 119-129) describes the
purification and analysis of a series of thiazine dyes. It concedes
that in former literature "published procedures appear to give
incomplete resolution of complex mixtures or separate them very
slowly." The paper describes only analytical separations, using
mixtures of alcohol/chloroform/acetic acid which are
disadvantageous because of the use of halogenated solvents and the
mixture not being stable over more than 24 hours. Also, the
separations had to be performed in the dark as the compounds showed
significant photodecomposition. Also see U.S. Pat. No. 3,641,016
(Korosi et al.).
[0013] Copending U.S. patent application Ser. No. 10/960,811 is
directed to an easy one-pot/one-step synthesis with crystallization
right from the reaction mixture; eliminates the use of halogenated
solvents and methanol during the reaction which also adds to
process safety, as methanol/bromine mixtures are hazardous;
eliminates the use of halogenated solvents and methanol in the work
up; completely eliminates the need to use chromatography which is
expensive, causes photodecomposition of material, requires the use
of halogenated solvents and silica and causes inconsistent purity
results; improves the yield using higher reaction temperature; and
results in consistent, high purity yields which are
reproducible.
[0014] While the described production procedure for phenothiazinium
dyes with a halide counter ion is favorable compared to procedures
described previously, the counter-anion being a halide may pose a
problem in some applications and processing steps because halides
may cause corrosion, especially when stainless steel devices are
used (as is often practiced in production facilities).
[0015] The present inventor have developed a novel process for
exchanging anions in phenothiazinium derivatives which reduces or
eliminates the corrosion problems caused by the conventional
halide-based phenothiazinium dyes.
SUMMARY OF THE INVENTION
[0016] The present invention pertains to a method for exchanging an
anion AA (preferably halide) of a 3,7-amino-phenothiazinium salt
for another anion BB. ##STR4##
[0017] The halide counteranion AA (or any other unwanted
counteranion) of phenothiazinium is replaced, according to the
present invention, by anion BB via at least one process step
selected from the group consisting of: [0018] (a) using ion
exchange resins; [0019] (b) using the concept that a strong acid
can replace a weak acid in its salt: e.g. (b1) using a stronger
acid than the corresponding acid that is formed from the original
counteranion to drive the weaker acid out, (b2) adding suitable
strong acids to weaker acids to make these acidic enough to drive
the original anion out (e.g., adding sulfuric acid to acetic acid),
(b3) driving the acid that is formed from the original counteranion
out of the mixture, e.g. using oxidation to remove the evolving HX
as X.sub.2 (where applicable, e.g. in the case of X.dbd.Cl.sup.-,
Br.sup.- . . . ), if necessary with the aid of a gas stream,
co-distillation or X.sub.2-scavenging chemicals e.g. containing
double bonds; and [0020] (c) using solubility differences: e.g.
(c1) introducing new anions of salt AX into the phenothiazine salt
BY by exploiting the insolubility of the newly formed salt AY or BX
in a suitably chosen solvent. If the new phenothiazine salt BX
stays in solution, AY is filtered off and BX is isolated from the
solution (e.g. by evaporation, precipitation . . . ). If the new
phenothiazine salt BX precipitates out, it is harvested by
filtration and dried. (c2) preferably: using silver salts that form
a less soluble salt with the original counteranion.
[0021] If the desired anion cannot be introduced by the above means
directly (e.g., because of lacking acidity or lacking solubility
differences), the above-mentioned methods can be combined,
preferably forming a less soluble hydroxide salt according to c1)
or a), then adding an acid of the desired anion which would
normally have been too weak to replace the original anion according
to b1).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] A process for producing a phenothiazinium compound
comprising the step of: reacting phenothiazine, in the presence of
a halogen, with at least one amine selected from the group
consisting of: ##STR5## wherein Z is CH.sub.2, O, S, SO.sub.2, NH,
NCH.sub.3, NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or NCOCH.sub.3, and
R.sup.1 and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY, and wherein the phenothiazinium compound has the
general formula: ##STR6## wherein A and B are each selected from
the group consisting of: ##STR7## wherein Z is CH.sub.2, O, S,
SO.sub.2, NH, NCH.sub.3, NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or
NCOCH.sub.3 and R.sup.1 and R.sup.2 are each independently linear
or branched C.sub.nH.sub.2nY, where n is 1-6, Y lo is H, F, Br, I,
OH, OCH.sub.3, OC.sub.2H.sub.5, OC.sub.3H.sub.7, CN or OCOCH.sub.3,
and where X.sup.- is a halide counteranion; and replacing the
halide counteranion with a non-halide counteranion.
[0023] The non-halide counteranion is at least one selected from
the group consisting of: mono- or di-carboxylic acid anions having
a carbon chain length of between about 1 to 6 (e.g., formate,
acetate, propionate etc.) hydrogensulfate, sulfate, phosphate,
hydrogenphosphate, dihydrogenphosphate, cyanate, nitrate, sulfide,
and other anions derived from non-organic acids.
[0024] The step of replacing the halide counteranion is at least
one selected from the group consisting of: exchanging the halide
counteranion with the non-halide counteranion via an ion exchange
resin; forming an acid of the halide counteranion and thereafter
adding a stronger acid than the acid of the halide counteranion to
thereby drive the weaker acid or the halide counteranion out of the
phenothiazinium compound forming an acid of the halide counteranion
and driving the acid of the halide counteranion out of the
phenothiazinium compound using oxidation to remove the evolving HX
as X.sub.2; and introducing a non-halide counteranion salt to a
salt of the halide counteranion containing phenothiazine mixture,
and separating and removing the halide counteranion, wherein a
non-halide counteranion salt of phenothiazine produced.
[0025] Alternatively, the step of replacing the halide counteranion
comprises: forming a less soluble hydroxide salt of the halide
counteranion; and adding an acid of the non-halide counteranion to
the hydroxide salt.
[0026] A process for producing a phenothiazinium compound
comprising the step of: reacting phenothiazine, in the presence of
a bromine, with at least one dialkylamine; and replacing the
bromine with a non-halide counteranion.
[0027] A phenothiazinium compound can be prepared from a mixture of
1-propanol/THF and the bromination in the presence of
di-n-propylamine so that the amination takes place immediately
after bromination in a simple one-pot/one-step synthesis process.
This eliminates the need for isolation by extraction and/or
chromatography, especially the elimination of chromatography due to
the fact that it disadvantageously uses vast amounts of halogenated
solvents and silica. The phenothiazinium compound synthesized
according to the aforementioned process crystallizes out of the
reaction mixture and is harvested by simple filtration. This
results in a very high quality crystallized phenothiazinium
compound (i.e., greater than 96% after crystallization determined
by high performance liquid chromatography (HPLC)) versus 30-60%
HPLC purity after conventional column chromatography.
[0028] This process can be used after a one step
halogenation/amination procedure (e.g., bromination/amination)
which produces phenothiazinium compounds from phenothiazine. This
process eliminates the use of undesirable halogenated solvents
throughout the synthesis process, since such a process typically
requires the use of methanol in the halogenation step of
phenothiazine which reacts violently with bromine.
[0029] A process for producing a phenothiazinium compound
comprising the step of: reacting phenothiazine, in the presence of
a halogen, with at least one amine selected from the group
consisting of: ##STR8## wherein Z is CH.sub.2, O, S, SO.sub.2, NH,
NCH.sub.3, NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or NCOCH.sub.3, and
R.sup.1 and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY; provided that each amine is the same or different
as the other amine.
[0030] The phenothiazinium compound preferably has the general
formula: ##STR9## wherein A and B are each selected from the group
consisting of: ##STR10## wherein Z is CH.sub.2, O, S, SO.sub.2, NH,
NCH.sub.3, NC.sub.2H.sub.5, NCH.sub.2CH.sub.2OH or NCOCH.sub.3 and
R.sup.1 and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY, where n is 1-6, Y is H, F, Br, I, OH, OCH.sub.3,
OC.sub.2H.sub.5, OC.sub.3H.sub.7, CN or OCOCH.sub.3, and where
AA.sup.- is a halide counteranion.
[0031] The halogen is selected from the group consisting of:
bromine, iodine, chlorine and mixtures thereof. The amine is diiso-
or di-n-alkylamine, e.g., diisopropylamine, diisobutylamine,
diisopentylamine, di-n-propylamine, di-n-butylamine,
di-n-pentylamine, or n-alkyl-iso-alkyl-amine, e.g.,
ethyl-isopropylamine.
[0032] It is preferable that the reaction occur at a temperature in
the range between about -5.degree. C. to +55.degree. C., more
preferably between about -5.degree. C. to +20.degree. C., and most
preferably between about 50.degree. C. to 55.degree. C.
[0033] The starting material phenothiazine preferably has the
formula: ##STR11##
[0034] The process according to the present invention may further
comprise the step of filtering the phenothiazinium compound.
[0035] It is preferable that the reaction is carried out in a
single reactor, wherein the phenothiazine and amine are mixed
together, followed by addition of the halogen.
[0036] Preferably, the present invention involves a process for
producing a phenothiazinium compound comprising the step of:
reacting phenothiazine, in the presence of a bromine, with at least
one dialkylamine. According to this embodiment, the phenothiazinium
compound has the general formula: ##STR12## wherein A and B are
each selected from the group consisting of: ##STR13## wherein
R.sup.1 and R.sup.2 are each independently linear or branched
C.sub.nH.sub.2nY, n is 1 to 6, and where AA.sup.- is a bromide
counteranion. Preferably, the dialkylamine is selected from the
group consisting of: diisopropylamine, diisobutylamine,
diisopentylamine, di-n-propylamine, di-n-butylamine,
di-n-pentylamine, ethyl-isopropylamine and mixtures thereof.
[0037] The present invention pertains to a method for exchanging an
anion AA (preferably halide) of a 3,7-amino-phenothiazinium salt
for another anion BB. ##STR14##
[0038] The halide counteranion AA (or any other unwanted
counteranion) of phenothiazinium is replaced, according to the
present invention, by anion BB via at least one process step
selected from the group consisting of: [0039] (a) using ion
exchange resins; [0040] (b) using the concept that a strong acid
can replace a weak acid in its salt: e.g. (b1) using a stronger
acid than the corresponding acid that is formed from the original
counteranion to drive the weaker acid out, (b2) adding suitable
strong acids to weaker acids to make these acidic enough to drive
the original anion out (e.g. adding sulfuric acid to acetic acid),
(b3) driving the acid that is formed from the original counteranion
out of the mixture, e.g. using oxidation to remove the evolving HX
as X.sub.2 (where applicable, e.g. in the case of X.dbd.Cl.sup.-,
Br.sup.- . . . ), if necessary with the aid of a gas stream,
co-distillation or X.sub.2-scavenging chemicals e.g. containing
double bonds; and [0041] (c) using solubility differences: e.g.
(c1) introducing new anions of salt AX into the phenothiazine salt
BY by exploiting the insolubility of the newly formed salt AY or BX
in a suitably chosen solvent. If the new phenothiazine salt BX
stays in solution, AY is filtered off and BX is isolated from the
solution (e.g. by evaporation, precipitation . . . ). If the new
phenothiazine salt BX precipitates out, it is harvested by
filtration and dried. (c2) preferably: using silver salts that form
a less soluble salt with the original counteranion.
[0042] If the desired anion cannot be introduced by the above means
directly (e.g., because of lacking acidity or lacking solubility
differences), the above-mentioned methods can be combined,
preferably forming a less soluble hydroxide salt according to c1)
or a), then adding an acid of the desired anion which would
normally have been too weak to replace the original anion according
to b1).
EXAMPLE 1
[0043] 3 g of a phenothiazinium salt was dissolved with stirring in
70 g concentrated H.sub.2SO.sub.4. A clear, green solution forms as
Br.sub.2-fumes evolve (as HBr is a weaker acid than
H.sub.2SO.sub.4, Br.sup.- is driven out and then oxidized to
Br.sub.2 which evolves from the mixture). The mixture was then
heated to 35.degree. C. and a vacuum of 50 mbar was applied. The
mixture foamed slightly. After 30 minutes, the green solution was
mixed into 120 mL water under cooling, the temperature was
15-38.degree. C. Immediately, brownish-bronze needles precipitated.
The mixture was then diluted with another 50 mL of water and left
standing overnight at room temperature. The solid was filtered,
washed with 50 ml water and dried at 50.degree. C. Ion
chromatography showed complete replacement of the Br in the salt.
HPLC confirmed the identity of the compound.
* * * * *