Title of Invention

"PROCESS FOR THE PREPARATION OF 4-{4-[({[4-CHLORO-3-(TRIFLUOROMETHYL)PHENYL]AMINO}CARBONYL)AMINO]PHENOXY}-N-METHYLPYRIDINE-2-CARBOXAMIDE AND ITS TOSYLATES SALT"

Abstract The present invention relates to a process for preparing 4-{4-[({[4~chloro-3-(trifluoro-methyl)phenyl]amino} carbonyl)amino]phenoxy}-N-rnethylpyridine-2-carboxarnide and its tosylate salt.
Full Text Process
The present invention relates to a process for preparing 4-{4-[({[4-chloro-3-(trifluoromethyl)-
phenyl]amino}carbonyl)amino]phenoxy}-A-methylpyridine-2-carboxaiTiide and its tosylate salt.
The tosylate salt of 4-{4-[({[4-chloro-3-(trifluoromethyl)phenyl]amino}carbonyl)aminoJphenoxy}-
jV-methylpyridine-2-carboxamide is mentioned in WO 03/068228 and WO 03/047579 and corresponds
to the compound of the formula (1):
(Figure Removed)
WO 03/068228 relates, inter alia, to the use of the compound of the formula (1) for treating disorders
in which angiogenesis plays an important role, for example in tumor growth. WO 03/047579
relates to arylureas in combination with cytotoxic or cytostatic compounds for treating cancer.
The compound 4-!4-[({[4-Chlor-3-(trifluormethyl)phenyl]amino}carbonyl)amino]phenoxy}--Nmethylpyridine-
2-carboxamide is described in WO 00/42012 and corresponds to the compound of
the formula (II):
(Figure Removed)
The compounds disclosed in WO 00/42012 and salts thereof, for example tosylates, are described
there as inhibitors of the enzyme Raf kinase and can be used to treat disorders, for example cancer.
Both WO 00/42012 and Bankston et al. (Organic Process Research & Development, 2002, 6, 777-
781) describe a process for preparing compound (11), which is illustrated in the following scheme:
(Figure Removed)
In the first step, picolinic acid is used, by reacting in thionyl chloride with addition of dimethylformamide,
to prepare (he acid chloride salt of the formula (HI). In a second stage, this is reacted
with methylamine to give the methylamide of the formula (IV), the methylamine being used dissolved
in tetrahydrofuran. The subsequent reaction in dimethylformamide with 4-aminophenol
with addition of potassium tert-butoxide and potassium carbonate affords the ether of the formula
(V) which is isolated by extraction and converted by further reaction with 4-chloro-3-lrifluoromethylphenyl
isocyanate in methylene chloride to the compound of the formula (II).
While the process disclosed by the prior art is effective for preparing the compound of the formula
(II), when preparing this compound on an industrial scale, followed by the preparation of the compound
of formula (I), factors such as product yields and process efficiency, safety and economy are
very significant as they are in any commercial process.
It is an object of the present invention to provide a process for preparing the compound of the formula
(11) and its tosylate salt on the industrial scale (kilogram to metric tonnes range) which satisfies
the criteria which apply in production and especially in the preparation of Pharmaceuticals,
and provides improvements in purity, environmental compatibility, industrial employability, safety
aspects and volume yield. This object is achieved by the present invention.
In the inventive preparation of the compound of the formula (I) a high solubility of the compound
of the formula (11) and therefore high volume yield is achieved by addition of water and/or by precharging
the reaction vessel with a definite amount of p-toluenesulfonic acid. Thus, pursuant to
GMF production a clarifying filtration is enabled.
In the inventive preparation of the compound of the formula (II) by reacting the compound of the
formula (V) with 4-chloro-3-trifluoromethyIphenyl isocyanate, it is possible, for example, to dispense
with the methylene chloride solvent and to shorten the reaction time.
In the inventive preparation of the compound of the formula (V) by reacting the compound of the
formula (IV) with 4-aminophenol, it is possible, compared to the prior art process, to avoid a technically
costly and inconvenient extraction step, to distinctly increase the volume yield, to obtain
the product with a higher purity by isolation and purification via its dihydrochloride salt and, if
appropriate, to dispense with the use of dimethylformamide. Surprisingly, it is possible, compared
to the prior art, also to dispense with the use of potassium carbonate.
In the inventive preparation of the compound of the formula (IV) by reacting the compound of the
formula (111) with rnethylamine, surprisingly it is possible to use an aqueous solution in spite of the
presence of the acid cloride of formula (III). In addition compared to the prior art process, for example,
the workup is simplified.
In the inventive preparation of the compound of the formula (III) from 2-picolinic acid, it is possible,
compared to the prior art process, to better control the course of the reaction and thus increase
safety in this reaction, in particular on the industrial scale. Due to the addition of bromide compounds
it is possible to dispense with the use of dimethylformamide in thionyl chloride which can
form dimethylcarbamoyl chloride. It is possible likewise to dipense with an isolation of the corrosive
product. The overall yield of the process according to the invention over three stages starting
from 2-picolinic acid up to the compound of the formula (V) is increased compared to the prior art
process.
The present invention provides a process for preparing the compound of the formula (I) which
comprises, in a first step, reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl
isocyanate in a nonchlorinated organic solvent, inert toward isocyanates, at a temperature
above 15°C to give the compound of the formula (II) and, in a second step, admixing the
compound of the formula (II) with p-toluenesulfonic acid.
Preparation of the compound of the formula (I):
The present invention comprises a process for preparing the compound of the formula (I) by
reacting the compound of the formula (II) with p-toluenesulfonic acid, wherein the reaction is
effected in a polar solvent at a reaction temperature of from 40°C up to the reflux temperature of
the solvent used.
The inventive preparation of the compound of the formula (I) is effected by reacting the compound
of the formula (11) with p-toluenesulfonic acid in a polar solvent at a reaction temperature of, for
example, from 40°C up to the reflux temperature of the solvent used, preferably at from 50°C up to
the reflux temperature of the solvent used, more preferably at from 50°C to 90°C. In order to
improve the solubility of the compound of the formula (II), if appropriate, to enable a clarifying
filtration and to reduce the amount of solvent, so that the compound of the formula (II) is kept in
solution, the compound of the formula (II) is first reacted with less than 1 mol, preferably with
from 0.10 to 0.7 mol, more preferably with from 0.13 to 0.4 mol, of p-toluenesulfonic acid, based
in each case on 1 mol of the compound of the formula (II). The preferred areas of the amount of
firstly admixed p-toluenesulfonic acid can vary marginally dependent on the solvent used. If
appropriate, water, preferably 12 to 14% water based on amount of organic solvent, can be
admixed. Subsequently, the reaction mixture is brought to reaction temperature and is, if
appropriate, filtered. Afterward, the remaining amount of the required amount of p-toluenesulfonic
acid is added. Optionally, the reaction mixture is admixed with seed crystals of the compound of
the formula (1) and cooled. The compound of the formula (I) is finally isolated by crystallization
and filtration. If water was added to the reaction mixture, the yield of the compound of formula
can be increased by removing water, for example by destination, and/or by addition of polar
solvent. Thereafter the water content in the reaction mixture is equal or less than 5%. The
compound of the formula (II) may, if appropriate, be used in the form of the crude product from
the preceding stage or in the form of a solution or suspension, for example dissolved in ethyl
acetate or tetrahydrofuran.
In the inventive preparation of the compound of the formula (I) by admixing the compound of the
formula (IJ) with p-toluenesulfonic acid, water is added to the reaction mixture and, if appropriate,
a clarifying filtration is conducted.
Particular preference is given to initially charging the compound of the formula (II) in a polar
solvent and to adding the p-toluenesulfonic acid, if appropriate dissolved or suspended in a polar
solvent.
p-Toluenesulfonic acid may be used either in anhydrous form or in the form of hydrates.
Preference is given to using p-toluenesulfonic acid monohydrate.
The amount of p-toluenesulfonic acid required for the inventive preparation of the compound of
the formula (I) is greater than or equal to 1 mol, preferably from 1 to 3 mol, more preferably from
1 to 1.5 mol, based in each case on 1 mol of the compound of the formula (II). The concentration
of the compound of the formula (II) in the reaction mixture is, for example, from 5 to 30,
preferably from 5 to 15, percent by weight. The concentration of p-toluenesulfonic acid in the
reaction mixture is, for example, from 1 to 15, preferably from 2 to 10, percent by weight.
Suitable polar solvents in the inventive preparation of the compound of the formula (I) are, for
example, organic solvents containing at-least one hydroxyl group, tetrahydrofuran, ethyl acetate or
mixtures of the solvents mentioned. Preferred solvents are methanol, ethanol, n-propanol,
isopropanol, n-bulanol, sec-butanol, isobutanol, n-pentanol, glycerol, ethylene glycol, dioxane,
dimethoxyethane, tetrahydrofuran, ethyl acetate or mixtures of the solvents mentioned. Particular
preference is given to ethanol, tetrahydrofuran, isopropanol, ethyl acetate or mixtures of the
solvents mentioned.
In order to increase the solubility of the reaction mixture and reduce the amount of solvent and
thus increase the volume yield, surprisingly it is possible to add a definite amount of water to the
solvent used. This is she more surprisingly because the compound of the formula (I) and the
compound of the formula (II) are both poor soluble in water alone (each 25°C). When water is added to the solvent, preference is given to attaining a solvent/water ratio of,
for example, from 4:1 to 60:1, preferably from 6:1 to 55:1. However, the amount of water should
not be so large that the crystallization of the compound of the formula (I) is prevented. Otherwise
water can be removed, for example, by destination. Preferably the water content at crystallization
is equal or less then 5%.
Preparation of the compound of the formula (11):
The present invention additionally comprises a process for preparing the compound of the formula
(II) by reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl isocyanate,
wherein the reaction is effected in a nonchlorinated organic solvent, inert toward isocyanates.
The inventive reaction of the compound of the formula (V) with the commercially available
chloro-3-trifluoromethylphenyl isocyanate to give the compound of the formula (II) is effected at a
temperature above 15°C and below 70°C, for example at a temperature of from 20°C to 60°C,
preferably at from 25°C to 60°C, more preferably at from 30°C to 60°C. Preference is given to
initially charging the compound of the formula (V) at a temperature of from 20°C to 60°C, more
preferably at from 30°C to 50°C, in a suitable organic solvent, and to admixing with 4-chloro-3-
trifluoromethylphenyl isocyanate, if appropriate dissolved or suspended in a suitable solvent, in
such a way that the reaction temperature does not exceed 70°C, preferably 65°C, more preferably
60°C. If appropriate, the crude product of the compound of the formula (II) is used in the following
stage dissolved or suspended in a suitable solvent, preferably in tetrahydrofuran or ethyl acetate.
The compound of the formula (II) is isolated preferably by crystallization from the reaction mixture,
by cooling the reaction mixture, for example, to a temperature of from -10 to 40°C, preferably
from 0 to 30°C, more preferably from 10 to 25°C.
Suitable organic solvents in the reaction of the compound of the formula (V) with 4-chloro-3-
trifluoromethylphenyl isocyanate to give the compound of the formula (II) are nonchlorinated or-
ganic solvents which are inert toward isocyanates, preferably tetrahydrofuran, ethyl acetate, dioxane,
methyl tert-butyl ether, dimethoxyethane or mixtures of the solvents mentioned. Particular
preference is given to ethyl acetate or tetrahydrofuran.
4-Chloro-3-trifluoromethylphenyl isocyanate is used in an amount of from 0.9 to 5 mol, preferably
from 1 to 3 mol, more preferably from 1 to 2 mol, based in each case on 1 mole of the compound of
the formula (V). The concentration of 4-chloro-3-trifluoromethylphenyl isocyanate in the reaction
mixture is from 5 to 30 percent by weight, preferably from 10 to 20 percent by weight, and the
concentration of the compound of the formula (V) in the reaction mixture is from 5 to 30 percent
by weight, preferably from 10 to 20 percent by weight.
It is possible to use the compound of the formula (II) in solution in the following stage without any
further work-up or isolation.
Preparation of the compound of the formula (V):
Variant A:
The present invention likewise comprises a process for preparing the compound of the formula (V)
by reacting the compound of the formula (IV) with 4-aminophenol without adding a carbonate salt.
The compound of the formula (IV) is preferably reacted with 4-aminophenol to give the compound
of the formula (V) in the presence of a base in a suitable solvent at a temperature of from 25°C up
to the reflux temperature of the solvent, preferably at from 60 to 110°C, within from 1 to 12 hours,
preferably within from 1 to 7 hours, more preferably within from 1 to 4 hours. For example, it is
cooled to from 0 to 30°C, preferably to from 5 to 25°C. In order to achieve a higher purity,
compared to the prior art, of the compound of the formula (V), the acid salt of the compound of the
formula (V) is first precipitated, isolated, dissolved again, admixed with a base, and then the
compound of the formula (V) is isolated by crystallization.
Particular preference is given to precipitating the acid salt of the compound of the formula (V) by
admixing the reaction mixture comprising the compound of the formula (V) with tetrahydrofuran,
cooling to a temperature of from -IO°C to 25°C and adding an acid, preferably hydrochloric acid,
more preferably an aqueous hydrochloric acid solution, to the reaction mixture in such a way that,
if appropriate, the temperature of 50°C, preferably 40°C, more preferably 30°C, is not exceeded.
Stirring is continued for up to 10 hours, preferably up to 5 hours, and the acid salt of the compound
of the formula (V), preferably the dihydrochloride salt of the compound of the formula (V), is
precipitated and isolated. After dissolution of the acid salt of the compound of the formula (V) in,
for example, water, a pH of from 2 to 5, preferably from 2.8 to 4, is established with a base,
preferably an aqueous alkali metal hydroxide solution, more preferably with an aqueous sodium
hydroxide solution, and, if appropriate, admixed with seed crystals of the compound of the formula
(V). Subsequently, an approximately neutral pH, preferably a pH of from 6 to 7, is established by
adding a base, preferably by adding an aqueous alkali metal hydroxide solution, more preferably
by adding an aqueous sodium hydroxide solution, and isolated by crystallizing the compound of
the formula (V).
In order to enable satisfactory crystallization of the acid salt of the compound of the formula (V),
the weight ratio, after addition of tetrahydrofuran, between solvent used and tetrahydrofuran is
from 5:1 to 1:2, preferably from 3:1 to 1:2, more preferably from 2.5:1 to 1.5:1.
A suitable solvent in the inventive reaction to give the compound of the formula (V) according to
variant A is a dipolar aprotic solvent. Preference is given to dimethylformamide, dimethyl sulfoxide,
N-methylpyrrolidorie, sulfolane or mixtures of the solvents mentioned. Particular preference is
given to dimethylformamide.
Suitable bases in the inventive reaction to give the compound of the formula (V) with
4-aminophenol according to variant A are alkali metal hydroxides and alkali metal alkoxides. Preference
is given to potassium tert-butoxide. Potassium tert-butoxide is preferably used in solution,
more preferably in a tetrahydrofuran solution.
In the inventive reaction to give the compound of the formula (V) according to variant A,
4-aminophenol is used in an amount of from 0:9 to 5 mol, preferably from 1 to 3 mol, more preferably
from I to 2 mol, and the base in an amount of from 1 to 3 mol, preferably from 1 to 2 mol,
based in each case on 1 mole of the compound of the formula (IV). The concentration of 4-
aminophenol in the reaction mixture is from 1 to 30 percent by weight, preferably from 4 to 15
percent by weight.
Variant B:
The present invention likewise comprises a process for preparing the compound of the formula (V)
by reacting the compound of the formula (IV) with 4-aminophenol in the presence of water, if
appropriate with addition of a phase transfer catalyst.
The reaction of the compound of the formula (IV) with 4-aminophenol to give the compound of
the formula (V) according to variant B is effected in the presence of a base, in the presence of
water and, if appropriate, with addition of a phase transfer catalyst, in a suitable solvent at a
temperature of from 25°C up to the reflux temperature of the solvent, preferably at from 40 to
90°C, more preferably from 50 to 80°C, within from 1 to 24 hours, preferably within from 2 to
15 hours, more preferably within from 4 to 12 hours. In order to achieve a higher purity of the
compound of the formula (V) compared to the prior art, the acid salt of the compound of the
formula (V) is precipitated, isolated, dissolved again, admixed with a base, and the compound of
the formula (V) is isolated by crystallization.
Particular preference is given to precipitating the acid salt of the compound of the formula (V) by
cooling the reaction mixture comprising the compound of the formula (V) to a temperature of from
-10°C to 25°C and adding an acid, preferably hydrochloric acid, more preferably an aqueous
hydrochloric acid solution, to the reaction mixture, in such a way that, if appropriate, the
temperature of 50°C, preferably 40°C, more preferably 30°C, is not exceeded. Stirring is continued
for up to 10 hours, preferably up to 5 hours, and the acid salt of the compound of the formula (V),
preferably the dihydrochloride salt of the compound of the formula (V), is precipitated and
isolated. After dissolution of the acid salt of the compound of the formula (V) in, for example,
water, a pH of from 2 to 5, preferably from 2.8 to 4, is established with a base, preferably with an
aqueous alkali metal hydroxide solution, more preferably with an aqueous sodium hydroxide
solution, and the mixture is admixed, if appropriate, with seed crystals of the compound of the
formula (V). Subsequently, an approximately neutral pH, preferably a pH of from 6 to 7, is
established by adding base, preferably by adding an aqueous alkali metal hydroxide solution, more
preferably by adding an aqueous sodium hydroxide solution and the compound of the formula (V)
is isolated by crystallization.
Suitable phase transfer catalysts are tetraalkylammonium salts. Preference is given to
tetraalkylammonium bromide, tetraalkylammonium chloride, tetraalkylammonium iodide,
tetraalkylammonium dihydrogenphosphate or tetraalkylammonium hydrogensulfate. Particular
preference is given to tetrabutylammonium hydrogensulfate.
Suitable solvents in the inventive reaction to give the compound of the formula (V) according to
variant B are alkylaromatics, dimethyl sulfoxide, dimethylformamide, sulfolane, N-methylpyrrolidonc,
tetrahydrofuran or a mixture of the solvents mentioned. Suitable with preference are
toluene, dimethyl sulfoxide, dimethylformamide, sulfolane, N-methylpyrrolidone, tetrahydrofuran
or a mixture of the solvents mentioned. Particular preference is given to tetrahydrofuran.
Suitable bases in the inventive reaction to give the compound of the formula (V) according to variant
B are alkali metal or alkaline earth metal hydroxides or alkali metal alkoxides. Preference is
given to alkali metal or alkaline earth metal hydroxides. Particular preference is given to sodium
hydroxide or potassium hydroxide. The base may be added without solvent and/or as an aqueous
solution.
In the inventive reaction to give the compound of the formula (V) according to variant B, 4-
aminophenol is used in an amount of from 0.9 to 5 mol, preferably in an amount of from 1 to 5
mol, more preferably from 1 to 3 mol, and the base in an amount of from 1 to 10 mol, preferably
from 1 to 7 mol, more preferably from 2 to 5 mol, based in each case on 1 mole of the compound of
the formula (IV). The concentration of 4-aminophenol in the reaction mixture is from 5 to 30 percent
by weight, preferably from 5 to 15 percent by weight, and the concentration of the base in the
reaction mixture is from 5 to 30 percent by weight, preferably from 5 to 15 percent by weight. The
amount of water in the reaction mixture is from 1 to 30 percent by weight, preferably from 2 to
20 percent by weight, more preferably from 4 to 15 percent by weight, based on the amount of
solvent used. In the presence of a phase transfer catalyst, the phase transfer catalyst is used in an
amount of from 0.1 to I mol, preferably from 0.1 to 0.5 mol, more preferably from 0.1 to 0.3 mol,
based on 1 mole of the compound of the formula (IV). The concentration of the phase transfer
catalyst in the reaction mixture is from 1 to 15 percent by weight, preferably from 2 to 10 percent
by weight.
When tctrahydrofuran is used as a solvent in the inventive reaction to give the compound of the
formula (V) according to variant B, the weight ratio between tetrahydrofuran and water is preferably
from 99:1 to 80:20, preferably from 98:2 to 90:10. The water present in the reaction solution
may, for example, be added in the form of an aqueous solution of a base.
Preparation of the compound of the formula (IV):
The present invention likewise comprises a process for preparing the compound of the formula
(IV) by reacting the compound of the formula (III) with an aqueous methylamine solution.
Instead of the aqueous methylamine solution, it is also possible to use gaseous methylamine.
In order to simplify the workup and the further reaction to give the compound of the formula (V)
compared to the prior art, an aqueous methylamine solution is initially charged or gaseous methylamine
is used and the formed crude product of the compound of the formula (IV) is used without
isolation in the subsequent reaction to give the compound of the formula (V).
Preference is given to reacting initially charged methylamine in an aqueous solution at a temperature
of from -2()°C to 30°C, preferably at'from -15°C to 20°C, more preferably at from -10°C to
10°C, with the compound of the formula (III), dissolved or suspended in a water-immiscible organic
solvent, in such a way that the reaction mixture does not exceed a temperature of 60°C, preferably
of 50°C, more preferably of 40°C. If appropriate, stirring is continued at a temperature of
from 10°C to 30°C, prei'erably from 15 to 25°C, for up to 4 hours. After phase separation, which is,
if appropriate, eased by adding sodium chloride, the compound of the formula (IV) is isolated.
In the reaction of the compound of the formula (111) with methylamine, the compound of the formula
(III) is preferably used dissolved or suspended in a water-immiscible organic solvent, for
example alkylaromatics or chloroaromatics, preferably xylene, toluene, trifluoromethylbenzene,
methyltetrahydrofuran, methyl tert-butyl ether or chlorobenzene, dichlorobenzene, more preferably
toluene. Particular preference is given to dissolving the compound of the formula (111) in toluene
and adding it to an aqueous methylamine solution.
The weight ratio between toluene and water in the reaction mixture is from 2:1 to 1:2.
Methylamine is used in excess, preferably in an amount of from 2 to 5 mol, based in each case on
1 mole of the compound of the formula (III). The concentration of methylamine in the reaction
mixture is from 5 to 30 percent by weight, preferably from 5 to 15 percent by weight.
Preference is given to using the compound of the formula (IV) without isolation in the subsequent
reaction to give the compound of the formula (V). After phase separation, particular preference is
given to not isolating the crude product of the compound of the formula (IV) by fully removing the
solvent, but rather using it in solution in the subsequent reaction to give the compound of the
formula(V).
A purification of the compound of the formula (IV) and conversion to a storage-stable form can be
effected, for example, if appropriate, by isolating the acid salt, preferably the hydrochloric acid salt
of the compound of the formula (IV). To this end, a solution comprising the crude compound of
the formula (IV) is admixed with an acid, preferably with hydrochloric acid, more preferably with
an aqueous hydrochloric acid solution, in such a way that the reaction temperature does not exceed
60°C, preferably 50°C, more preferably 40°C. After cooling, the acid salt, preferably the hydrochloric
acid salt, of the compound of the formula (IV) is isolated by crystallisation.
Preparation of the compound of the formula (III):
The present invention likewise comprises a process for preparing the compound of the formula
(III) by reacting 2-picolinic acid with thionyl chloride, wherein a solvent inert toward thionyl chloride
is used, the thionyl chloride is added to the 2-picolinic acid and the use of dimethylformamide
is avoided.
In the preparation of the compound of the formula (III), 2-picolinic acid is initially charged in a
solvent inert toward thionyl chloride at from 30°C to 90°C, preferably at from 40°C to 80°C, and
reacted with thionyl chloride in such a way that gas evolution can be controlled efficiently. For
example, stirring is continued at a temperature of from 40 to 110°C, preferably from 50 to 100°C,
for up to 24 hours. The reaction takes place, if appropriate, in the presence of a bromide compound,
preferably hydrogen bromide, lithium bromide, sodium bromide, potassium bromide, 2-
picolinic acid hydrobromide or thionyl bromide, more preferably hydrogen bromide. The use of
dimethylformamide is avoided. After cooling to a temperature of, for example, from 10°C to 40°C,
the volatile constituents, for example the solvent or residues of thionyl chloride, are removed preferably
by applying a vacuum, and the compound of the formula (111) is isolated.
The bromide compound is added to the reaction solution at the start of the reaction or after thionyl
chloride addition. Preference is given to adding sodium bromide, potassium bromide or thionyl
bromide at the start ol the reaction. Hydrogen bromide, for example as a gas or as an acetic acid
solution, is preferably added to the reaction solution from 1 to 5 hours, preferably from 1 to
2 hours, after addition of thionyl chloride.
In the preparation of the compound of the formula (III), particular preference is given to adding
hydrogen bromide, in gaseous form or as a solution. A suitable hydrogen bromide solution is a
solution of hydrogen bromide in acetic acid.
A useful solvent in the preparation of the compound of the formula (III) is a solvent inert toward
thionyl chloride, preferably a chlorinated aromatic hydrocarbon, or a higher-boiling, chlorinated
aliphatic hydrocarbon, more preferably chlorobenzene.
Preference is given to dissolving or suspending the compound of the formula (III) without isolation
in a suitable solvent, preferably in a water-immiscible, organic solvent, for example xylene, toluene,
trifluoromethylbenzene, methyltetrahydrbfuran, methyl tert-butyl ether or chlorobenzene,
preferably toluene, and using it in the subsequent reaction to give the compound of the formula
(IV).
Thionyl chloride is used in excess, preferably in an amount of from 2 to 15 mol, preferably from 2
to 8 mol, more preferably from 2 to 6 mol, based in each case on 1 mol of 2-picolinic acid. Hydrogen
bromide is used in an amount of from 0.1 to 0.5 mol, preferably from 0.1 to 0.3 mol, based in
each case on 1 mole of 2-picolinic acid. Sodium bromide is used in an amount of from 0.1 to 0.5
mol, preferably from 0.1 to 0.3 mol, based in each case on 1 mole of 2-picolinic acid. Thionyl bromide
is used in an amount of from 0.01 to 0.2 mol, preferably from 0.02 to 0.15 mol, based in each
case on 1 mole of 2-picolinic acid. The concentration of thionyl chloride in the reaction mixture is
from 30 to 80 percent by weight, preferably from 40 to 70 percent by weight, and the concentration
of 2-picolinic acid in the reaction mixture is from 5 to 40 percent by weight, preferably from 10 to
25 percent by weight. The concentration of hydrogen bromide in the reaction solution is from 0.5
to 10, preferably from 0.75 to 5, percent by weight, the concentration of sodium bromide in the
reaction solution is from 1 to 10, preferably from 1 to 5, percent by weight, the concentration of
thionyl bromide in the reaction solution is from 0.5 to 10, preferably from 0.75 to 5, percent by
weight.
The present invention comprises a process for preparing the compound of the formula (I), if appropriate
starting from 2-picolinic acid by reacting with thionyl chloride to give the compound of
the formula (III) as described under "Preparation of the compound of the formula (III)", if appropriate
subsequently reacting the compound of the formula (III) with an aqueous methylamine solution
to give the compound of the formula (IV) as described under "Preparation of the compound of
the formula (IV)", if appropriate subsequently reacting the compound of the formula (IV) with 4-
aminophenol to give the compound of the formula (V) as described under "Preparation of the compound
of the formula (V)", subsequently reacting the compound of the formula (V) with 4-chloro-
3-trifiuoromethyl-phenyl isocyanate as described under "Preparation of the compound of the formula
(II)" and finally reacting the compound of the formula (II) with p-toluenesulfonic acid as
described under "Preparation of the compound of the formula (I)".
Preference is given to a process for preparing the compound of the formula (I), wherein, in a first
step, the compound of the formula (V) is reacted with 4-chloro-3-trifluoromethyl-phenyl isocyanate
in a nonchlorinated organic solvent, inert toward isocyanates, at a temperature above 15°C to
give the compound of the formula (II) and, in a second step, the compound of the formula (II) is
admixed with p-toluenesulfonic acid. ,
Preference is likewise given to obtaining the compound of the formula (I) by first reacting the
compound of the formula (IV) with 4-aminophenol without adding a carbonate salt to give the
compound of the formula (V) and, if appropriate, precipitating the hydrochloric acid salt of the
compound of the formula (V) in the presence of tetrahydrofuran and/or water, dissolving it in water
and, by establishing a pH of from 6 to 7, isolating the compound of the formula (V) by crystallization,
secondly reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl
isocyanate in ethyl acetate to give the compound of the formula (II), and thirdly reacting the compound
of the formula (II) with p-toluenesulfonic acid.
Particular preference is given to a process for preparing the compound of the formula (1), wherein,
in a first step, the compound of the formula (V) is reacted with 4-chloro-3-trifluoromethylphenyl
isocyanate in a nonchlorinated organic solvent, inert toward isocyanates, at a temperature above
15°C to give the compound of the formula (II) and, in a second step, the compound of the formula
(II) is reacted with p-toluenesulfonic acid in a polar solvent at a reaction temperature of from 40°C
up to the reflux temperature of the solvent used.
Particular preference is likewise given to obtaining the compound of the formula (1) by first reacting
2-picolinic acid in a solvent inert toward thionyl chloride by adding thionyl chloride and, if
appropriate, a bromide compound to give the compound of the formula (III), secondly adding the
compound of the formula (III) without isolation, dissolved in toluene, to an aqueous methylamine
solution to give the compound of the formula (IV), thirdly reacting the compound of the formula
(IV) with 4-aminophenol in the presence of a base to give the compound of the formula (V), forming
the hydrochloric acid salt of the compound of the formula (V) in the presence of tetrahydrofuran
and/or water, dissolving it in water and, by establishing a pH of from 6 to 7, isolating the coinpound
of the formula (V) by crystallization, fourthly reacting the compound of the formula (V)
with 4-chIoro-3-trifluoromethylphenyI isocyanate in, if appropriate, ethyl acetate to give the compound
of the formula (II), and fifthly reacting the compound of the formula (II) with
p-loluenesulfonic acid.
The present invention likewise comprises a process for preparing the compound of the formula
(II), if appropriate starting from 2-picolinic acid by reacting with thionyl chloride to give the compound
of the formula (III) as described under "Preparation of the compound of the formula (III)", if
appropriate subsequently reacting the compound of the formula (III) with an aqueous methylamine
solution to give the compound of the formula (IV) as described under "Preparation of the compound
of the formula (IV)", if appropriate subsequently reacting the compound of the formula (IV)
with 4-aminophenol to give the compound of the formula (V) as described under "Preparation of
the compound of the formula (V)", and subsequently reacting the compound of the formula (V)
with 4-chloro-3-trifluoromethyIphenyl isocyanate as described under "Preparation of the compound
of the formula (II)".
Preference is given to obtaining the compound of the formula (II) by firstly reacting the compound
of the formula (IV) with 4-aminophenol without adding a carbonate salt to give the compound of
the formula (V) and, if appropriate, precipitating the hydrochloric acid salt of the compound of the
formula (V) in the presence of tetrahydrofuran and/or water, dissolving it in water and, by establishing
a pH of from 6 to 7, isolating the compound of the formula (V) by crystallization, and secondly
reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl isocyanate
in, if appropriate, ethyl acetate.
Particular preference is given to obtaining the compound of the formula (II) by firstly reacting 2-
picolinic acid in a solvent inert toward thionyl chloride by adding thionyl chloride and, if appropriate,
a bromide compound to give the compound of the formula (III), secondly adding the compound
of the formula (111) without isolation, dissolved in toluene, to an aqueous methylamine solution
and reacting it to give the compound of the formula (IV), thirdly reacting the compound of the
formula (IV) with 4-aminophenol in the presence of a base to give the compound of the formula
(V), forming the hydrochloric acid salt of the compound of the formula (V) in the presence of tetrahydrofuran
and/or water, dissolving it in water and, by establishing a pH of from 6 to 7, isolating
the compound of the formula (V) by crystallization, fourthly reacting the compound of the formula
(V) with 4-chloro-3-trifluoromethylphenyl isocyanate in, if appropriate, ethyl acetate.
The reactions are generally carried out at atmospheric pressure. However, it is also possible to work
at elevated pressure or at reduced pressure (for example in a range of from 0.5 to 5 bar).
The present invention likewise includes all combinations of the areas of preference.
The present invention will now be illustrated in detail with reference to nonlimitng preferred
examples. Unless stated otherwise, all amounts relate to percentages by weight.
Abbreviations:
DC] direct chemical ionization (in MS)
DM1-' dimethylformamide
DMSO dimethyl sulfoxide
Kl electron impact ionization (in MS)
KSI electrospray ionization (in MS)
h hour(s)
min rninute(s)
m.p. melting point
MS mass spectrometry
NMR nuclear resonance spectroscopy
THF tetrahydrofuran
Working examples:
'H-NMR spectra were recorded at room temperature using spectrometers from Bruker. Deuterium
dimethylsulfoxide was used as solvent including tetramethylsilan as internal standard (if not otherwised
mentioned).
MS spectra were recorded using spectrometers from Waters and Applied Biosystems. The relative
signal intensity is stated (in percent based on the basis peak).
HPLC was performed using HP 1100 from Hewlett Packard. The definite conditions are stated
with the respective working examples.
Preparation of 4-{4-K|[4-chloro-3-(trifluoromethvl)phenvllamino}carbonvl)aminolphenoxv}-/
V-mcthylpvridine-2-carboxamide and its tosylate salt
Stage 1:
4-Criloropyridine-2-carbonyl chloride hydrochloride
Method la:
2-Picolinic acid (60 kg, 487 mol) is suspended in chlorobenzene (85 kg) and heated to 70°C. Thionyl
chloride (262.5 kg, 2206 mol) is added to such a degree that the gas evolution (mainly SC>2 and
HC1) can be controlled efficiently. After stirring at 70°C for 1 hour, gaseous hydrogen bromide (6
kg, 74 mol) is passed into the reaction vessel over 1 h . The reaction mixture is then heated to 90°C
and stirred for 13 h. After cooling to 30°C, excess thionyl chloride and the majority of the chlorobenzene
are distilled off under reduced pressure (final vacuum 50 mbar at jacket temperature
75°C). Toluene (120 kg) is added and the vacuum distillation is repeated (final vacuum 50 mbar at
jacket temperature 75°C) in order to remove thionyl chloride still remaining and the majority of
the toluene. Alter toluene has again been added (225 kg), the crude 4-chloropyridine-2-carbonyl
chloride hydrochloride is used in the next stage as the toluene solution.
Method Jl>:
2-Picolinic acid (60 kg, 487 mol) is suspended in chlorobenzene (85 kg) and thionyl bromide
(5.1 kg, 25 mol) is added. After heating to 72°C, thionyl chloride (200 kg, 168 1 mol) is added
to such a degree that the gas evolution (mainly SO2 and HC1) can be controlled efficiently. The
reaction mixture is subsequently heated to 90°C and stirred for 13 h. After cooling to 20°C, excess
thionyl chloride and the majority of the chlorobenzene are distilled off under reduced pressure
(final vacuum 50 mbar at jacket temperature 75°C). Toluene (120 kg) is added and the vacuum
distillation is repeated (final vacuum 50 mbar at jacket temperature 75°C), in order to remove thionyl
chloride slill remaining and the majority of the toluene. After toluene has been added again
(225 kg), the crude 4-chloropyridine-2-carbonyl chloride hydrochloride is used in the next stage as
the toluene solution.
Method Ic:
2-Picolinic acid (28.3 kg, 230 mol) and sodium bromide (3.8 kg, 37 mol) are suspended in chlorobenzene
(40 kg). After heating to 50°C, thionyl chloride (94.5 kg, 794 mol) is added to such a degree
that the gas evolution (mainly SO2 and HC1) can be controlled efficiently. The reaction mixture
is subsequently heated to 85°C and stirred for 19 h. After cooling to 20°C, excess thionyl
chloride and the majority of the chlorobenzene are distilled off under reduced pressure (final vacuum
50 mbar at jacket temperature 75°C). Toluene (62 kg) is added and the vacuum distillation is
repeated (final vacuum 50 mbar at jacket temperature 75°C), in order to remove thionyl chloride
still remaining and the majority of trie toluene. After toluene has been added again (80 kg), the
crude 4-chloropyridine-2-carbonyl chloride hydrochloride is used in the next stage as the toluene
solution.
Stage 2:
A reaction vessel is laden with methylamine as a 40% aqueous solution (117 kg, 1507 mol of methylamine).
Water (97.5 kg) is added and the solution is cooled to -5°C. A solution of the crude 4-
chloropyridine-2-carbonyl chloride hydrochloride (approx. 330 kg, including toluene, obtained
from 60 kg of 2-picolinic acid by the process detailed in stage 1 / method la) in toluene is added to
such a degree that the temperature of the reaction mixture does not exceed 30°C. After stirring
further at 20°C, for 1 h, the insoluble constituents are filtered out of the reaction mixture. After the
phases have been separated, the organic phase is washed with water (90 kg). For better phase separation,
5 kg of sodium chloride are added. The majority of the toluene is distilled out of the organic
phase under reduced pressure (final vacuum 40 mbar at jacket temperature 95°C). The crude 4-
chloro-/V-methylpyridine-2-carboxamide is thus obtained as an orange- to dark brown-colored oil
and is used in the next stage without further purification.
The crude product may be purified via the hydrochloride salt and isolated:
37% hydrochloric acid (354 g, 3.59 mol) is added with stirring to a solution of the crude 4-chloroyV-
methylpyridine-2-carboxamide (500 g, 2.93 mol) in acetone (2 kg) to such a degree that the temperature
of the reaction mixture does not exceed 40°C. After cooling to approx. 5°C, stirring is
continued for I h. The product is filtered off, washed with acetone (580 g) and dried under reduced
pressure (50°C, 80 mbar). In this way, 521 g (86% of theory) of 4-chloro--N-methylpyridine-2-
carboxamide hydrochloride are obtained.
m.p. 166-168°C
'H NMR (DMSCMi, 500 MHz): 6 = 2.83 (d, J = 4:8 Hz, 3H, NCH3); 3.88 (br. s, HC1 / H2O); 7.77
(dd,J= 1.9,5.1 H/, 1H, 5-H); 8.03 (d,J= 1.6, 1H, 3-H); 8.63 (d, J= 5.2 Hz, HI, 6-H); 8.90 (br.
s, 1 H, NH)
MS [DC1, NH3]: m/e = 188 [M+NH,]', 171 [M+H.]+ (M = free base).
Stage 3:
4-(4-Aminophenoxy)-N-methylpyridine-2-carboxamide
Method 3a:
In a reaction vessel, approx. 93 kg of crude 4-chloro-N-methylpyridine-2-carboxamide (obtained
starting from 60 kg of 2-picolinic acid in the abovementioned reaction steps) are admixed with
dimethylformamide (445 kg) and to the solution are added successively p-aminophenol (50.5 kg,
463 mol) and potassium tert-butoxide (273 kg, 487 mol of a 20% solution in tetrahydrofuran). The
vessel contents are heated to 90°C and stirred at this temperature for 2 h. After cooling to 15°C,
tetrahydrofuran (212 kg) is added and 37% hydrochloric acid (116.5 kg, 1181 mol) is added to
such a degree that the temperature of the reaction mixture does not exceed 30°C. After subsequently
stirring for 1 h, the precipitated product is filtered off and washed twice with tetrahydrofuran
(178 kg each time). After blow-drying, the product is dissolved in distilled water (570 kg) and
a pH of from 3.3 to 3.5 is established initially at 20°C by adding 10% sodium hydroxide solution
(193 kg, 483 mol). At this pH, the solution is seeded with the title compound (0.5 kg) and subsequently
stirred for 30 min. Afterward, addition of further 10% sodium hydroxide solution (118 kg,
296 mol) at 20°C within 1 h establishes a pH of from 6 to 7 and the mixture is stirred for a further
30 min. The suspension is filtered, the solid is washed with distilled water (350 kg) and dried at
approx. 60°C under reduced pressure. 92 kg (78% of theory over three stages) of the title compound
are obtained.
Method 3b:
In a reaction vessel, approx. 93 kg of crude 4-chloro-N-methylpyridine-2-carboxamide (obtained
starting from 60 kg of 2-picolinic acid in the abovementioned reaction steps) are admixed successively
with letrahydrofuran (350 kg), 4-aminophenol (58.4 kg, 535 mol), tetra-.-N-butylammonium
hydrogensulfate (33.1 kg, 97.5 mol), solid sodium hydroxide (29.1 kg, 726 mol) and 45% sodium
hydroxide solution (65.3 kg, 734 mol). The mixture is heated to 65°C and stirred at this temperature
for 8 h. After cooling to 20°C, 37% hydrochloric acid (238 kg, 2408 mol) is added to such a
degree that the temperature of the reaction mixture does not exceed 25°C. After stirring further for
I h, the precipitated product is filtered off and washed with tetrahydrofuran (300 kg). After the
still-moist product has been dissolved in water (920 kg), the pH of the mixture is adjusted to from
pH 3 to 3.5 at 20°C by adding 22.5% sodium hydroxide solution (70.7 kg, 398 mol). The mixture
is seeded with the title compound (0.5 kg), and the addition of 22.5% sodium hydroxide solution
(50 kg, 281 mol) is continued until a pH of from 6 to 7 has been attained. The suspension is stirred
further for 1 h, and the product is subsequently filtered off, washed with water (150 kg) and dried
under reduced pressure (50°C, final vacuum three stages) of the title compound are obtained as light brown crystals.
m.p. 114-116°C
'H-NMR (DMSO- 6.86 (AA'BB' quarter!,./ = 8.6 Hz, 4H, aromatic); 7.08 (dd, J= 2.4, 5.4 Hz, 1H, 5-H); 7.33 (d, ./ =
2.3 Hz, 1H, 3-H); 8.46 (d, 7=5.5 Hz, 1H, 6-H); 8.78 (br. d, J= 4.5 Hz, 1H,NH)
MS (El): m/c =• 243 [M|", 186 [M-CONHCH3]+, 109.
HPLC: Inertsil ODS 3. 5um, ID 3 mm, length 25 cm, (stationary phase); flow: 0.5 mL/min.; 245
nm; eluent A: neutral ammonium acetate buffer, eluent B: 20 mL neutral ammonium acetate
buffer, 400 ml, acetoniiril, 400 mL methanol; linear gradient 12.5% B -> 100%B (15 min.).
Retentiontime: 12.6 min.; purity: >95%.
Stase 4:
4d'4-|({[4-Chloro-3-(trinuorornethyl)phenvl1amino}carbonyl)amino]phenoxyi-7V-methylpyridine-
2-carboxamide
4-(4-Aminophenoxy)-A;-methyl-2-pyridinecarboxamide (52.3 kg, 215 mol) is suspended in ethyl
acetate (146 kg) and the suspension is heated to approx. 40°C. 4-Chloro-3-trilluoromethylphenyl
isocyanate (50 kg, 226 mol), dissolved in ethyl acetate (58 kg), is then added to such a degree that
the temperature is kept below 60°C. After cooling to 20°C within 1 h, the mixture is stirred for a
further 30 min and the product is filtered off. After washing with ethyl acetate (30 kg), the product
is dried under reduced pressure (50°C, 80 mbar). 93 kg (93% of theory) of the title compound are
obtained as colorless to slightly brownish crystals.
m.p. 206-208°C
'H-NMR (DMSO-rfrf, 500 MHz): 8 = 2.79 (d, J = 4.4 Hz, 3H, NCH3); 7.16 (dd, 7= 2.5, 5.6 Hz, 1H,
5-H); 7.18 (d,./= 8.8 Hz, 2H, 3'-H, 5'-H); 7.38 (d, .7=2.4 Hz, 1H, 3-H); 7.60-7.68 (m, 4H, 2'-H,
6'-H, 5"-H,6"-H);;8.l3(d,J= 1.9 Hz, 1H, 2"-H); 8.51 (d, .7= 5.6 Hz, 1H, 6-H); 8.81 (d,J=4.5
Hz, 1H, NHCH;0; 9.05 (br. s, 1H, NHCO); 9.25 (br. s, 1H, NHCO)
MS (ESI, Cl 13CN/H2O): m/e = 465 [M+HJ '.
Stase 5:
4- {4jX|[4-Chloro-3 -f trifluoromethyl)'phenyl]amJino} carbonyl)amino]phenoxy} --N-methylpyridine-
2-carboxamide tosylate
Method 5a:
4.{4-|({[4-Chloro-3-(trinuoromethyl)phenyl]amino}carbonyl)amino]phenoxy}-A'-inethylpyridine-
2-carboxamide (47.5 kg, 100 mol) is suspended in ethanol (432 kg) and p-toluenesulfonic acid
monohydrate (6.8 kg, 36 mol) is added. The mixture is stitrred for 15 min. and the suspension has
been heated to 74°C within 0.5 h. After the mixture is clarified by filtration, further ptoluenesulfonic
acid monohydrate (16.8 kg, 88 mol) is added within 40 min. as a filtered solution
in ethanol (41 kg). The crystallization of the product is induced by seeding at 74°C with 0.63 kg of
the title compound. After cooling to 3°C within 120 min., the mixture is stirred for a further 1 h
and the product is filtered off. The solid is washed twice with ethanol (88 kg each time) and dried
under reduced pressure. 58 kg (91% of theory) of the title compound are obtained as colorless to
slightly brownish crystals.
m.p. 223-23 1°C (melting under decomposition)
'H-NMR (DIVISOR, 500 MHz): d = 2.29 (s, 3H, CH3); 2.79 (d, J= 4.8 Hz, 3H, NCH3); 5.9 (br. s,
1H, SCM-I), 7 . l 4 ( d , J 7.9 Hz, 2H, 2"'-H, 6"'-H); 7.17-7.22 (m, d, 7= 8.8 Hz , 3H, 5-H, 3'-H,
5'-H); 7.44 (d. .7 = 2.0 Hz, 1H, 3-H), ); 7.48 (d,./ = 8.0 Hz, 2H, 3"'-H, 5"'-H), 7.61 (d, J= 8.8 Hz,
2H, 2MI, 6'-H), 7.63 (in, 1H, 5"-H), .7.67 (m, 1H, 6"-H), 8.14 (d, J=2.2 Hz, 1H, 2"-H),8.53 (d,
./= 5.6 Hz, 1H, 6-H); 8.88 (d, J = 4.8 Hz, 1H, NHCH3); 9.10 (br. s, 1H, NHCO); 9.30 (br. s, IH,
NHCO).
MS (ESI, CH3CN/H2O): m/e = 465 [M+H]+.
HPLC: Zorbax Eclipse XDB C-8, 3.5 \im, ID 2.1 mm, length 15 cm (stationary phase); flow: 0.6
mL/min.; 235 nm; eluent A: acidic phosphate buffer, eluent B: ethanol/acetonitril=4/6 (V/V), linerar
gradient 5% B -> 43.5% B (22 min.), subsequently linear gradient 43.5% B -> 90% B (8
min.).
Retentiontimes: p-tolucnesulfonic acid: (R| 1.8 min.); title compound: (Rt 25.5 min.) purity:
>99%.
Method_5b_:_
4-{4-|({|4-C 2-carboxamide (50 g, 0.1076 mol) are suspended in isopropanol (300 g). Subsequently,
p-toluenesulfonic acid inonohydrate (7.4 g, 0.039 mol) and 50 g of water are added. After the suspension
has been heated to 74°C within In, it is filtered and a filtered solution of p-toluenesulfonic
acid inonohydrate (17.13 g, 0.09 mol) in isopropanol (50 g) is added at 70°C within 40 min.. After
seeding at 74 °C with the title compound the mixture is cooled to 30°C within 90 min. and isopropanol
and water are distilled off under reduced pressure (70-100 mbar) within 1.5 to 3 h. During
destination isopropanol (400 g) is added. Afterward the mixture is stirred at 20°C for 0.5 h. The
product is filtered off, washed twice with isopropanol (140 g each time) and dried under reduced
pressure. 61.9 g (90% of theory) of the title compound are obtained as colorless to slightly
brownish crystals.
Method 5c:
4-{4-[({[4-Chloro-3-(trinuoromethyl)phenyl]amino}carbonyl)amino]phenoxy}-N-methylpyridine-
2-carboxamide (50 g, 0.1076 mol) are suspended in ethyl acetate (500 g) and water (10 g). The
mixture is heated to 69°C within 0.5 h and a filtered solution of p-toluenesulfonic acid monohydrate
(3.26 g, 0.017 mol) in mixture of water (0.65 g) and ethyl acetate (7.2 g) is added. After
filtration a filtered solution of p-toluenesulfonic acid monohydrate (22 g, 0.11 mol) in a mixture of
ethyl acetate (48 g) and water (4.34 g) is added. The mixture is cooled to 23°C within 2 h. The
product is filtered off, washed twice with ethyl acetate (92.5 g each time) and dried under reduced
pressure. 65.5 g (96% of theory) of the title compound are obtained as colorless to slightly
brownish crystals.
Method-Mi.lslSge_4_\-__5 ax a one-stage process)
4-(4-Aininophenoxy)-/V-methyl-2-pyridinecarboxamide (26.2 g, 0.1077 mol) is suspended in ethyl
acetate (320 g) and the suspension is heated to approx. 40°C. After filtration a filtered solution of
4-chloro-3-trifiuoromethylphenyl isocyanate (25 g, 0.113 mol) in ethyl acetate (32 g), is added to
such a degree that the temperature is kept below 40°C. The mixture is heated to 71°C within 30
min. and, alter addition of 10 g of water, a filtered solution of p-toluenesulfonic acid monohydrate
(24.8 g, 0.13 mol), in a mixture of ethyl acetate (20.4 g) and water (6.7 g), is metcred in within 40
min.. After filtration, seeding with the title compound at 71 °C and cooling to 25°C within 2 h, the
product is filtered off. After washing twice with ethyl acetate (92.5 g), the product is dried under
reduced pressure (50°C, 125 mbar). 65.8 kg (96.0% of theory) of the title compound are obtained
as colorless to slightly brownish crystals.
Method ^: (stage 4 j• .5 as a one-stage process)
4-(4-Aminophenoxy)-A-methyl-2-pyridinecarboxamide (10.4 g, 0.0427 mol) is dissolved at 25°C
in tetrahydrofuran (44.4 g) and 4-chloro-3-trifluoromethylphenyl isocyanate (10 g, 0.0448 mol),
dissolved in tetrahydrofuran (6.8 g), is added to such a degree that the temperature is kept below
25°C. The mixture is heated to 64°C within 0.5 h and after filtration a filtered solution of ptoluenesulfonic
acid monohydrate (9.7 g, 0.05 mol), dissolved in tetrahydrofuran (27 g), is added.
Subsequently, the mixture is filtered, seeded with the title compound at 64°C and cooled to 0°C
within 3 h and the product is filtered off. After washing twice with tetrahydrofuran (18.5 g), the
product is dried under reduced pressure (50°C, 300 mbar). 22.2 kg (81.6% of theory) of the title
compound are obtained as colorless to slightly brownish crystals.



WE CLAIM:
1. A process for preparing the compound of the formula (I)
which comprises, in a first step, reacting the compound of the formula (V)
with 4-chloro-3-trifluoromethylphenyl isocyanate in a nonchlorinated organic
solvent, inert toward isocyanates, by initialIy charging the compound of the
formula (V) at a temperature of from 20°C to 60°C and admixing with 4-
chloro-3-trifluoromethylphenyl isocyanate in such a way that the reaction
temperature does not exceed 70" C to give the compound of the formula (11)
and, in a second step, admixing the compound of the formula (11) with ptoluenesulfonic
acid in a polar solvent at a reaction temperature of from 40" C
up to the reflux temperature of the solvent used.
2. A process as claimed in claim 1 wherein the compound of the formula (V) is
reacted with 4-chloro-3-trifluoromethylphenyl isocyanate in a nonchlorinated
organic solvent, inert towards isocyanates, by initially charging the
compound of the formula (V) at a temperature of from 20°C to 60°C and
admixing with 4-chloro-3-trifluoromethylphenyl isocyanate in such a way
that the reaction temperature does not exceed 70°C to give the compound of
formula (11).
3. The process as claimed in claim 1 or 2, wherein the compound of the formula
(V) is prepared by reacting the compound of the formula (IV)
with karninophenol without adding a carbonate salt.
4. The process as claimed in claim 1 or 3, wherein, in the preparation of the
compound of the formula (V), the acid salt of the compound of the formula
(V) is first precipitated, isolated, dissolved again, admixed with a base, and
then the compound of the formula (V) is isolated by crystallization.
5. The process as claimed in claim 3 or 4, wherein the compound of the formula
(IV) is prepared by reacting the compound of the formula (111)
with an aqueous methylamine solution.
6. The process as claimed in claim 5, wherein the compound of the formula (111)
is prepared by using a solvent inert toward thionyl chloride, adding thionyl
chloride to Zpicolinic acid and without using of dimethylformamide.
7. A process for preparing the compound of the formula (I) as claimed in any
preceding claims, wherein the compound of the formula (11) is reacted with ptoluenesulfonic
acid, by effecting the reaction in a polar solvent at a reaction
temperature of from 40" C up to the reflux temperature of the solvent used
and admixing of water thereto.
8. The process as claimed in claim 1 or 3 to 7, wherein p-toluenesulfonic acid is
p-toluenesulfonic acid monohydrate.

Documents:

2260-delnp-2007-1-Abstract-(26-03-2013).pdf

2260-delnp-2007-1-Correspondence Others-(19-02-2013).pdf

2260-delnp-2007-1-Correspondence Others-(26-03-2013).pdf

2260-delnp-2007-1-Form-2-(26-03-2013).pdf

2260-delnp-2007-1-Form-3-(19-02-2013).pdf

2260-delnp-2007-1-GPA-(26-03-2013).pdf

2260-delnp-2007-abstract.pdf

2260-delnp-2007-Assignment-(03-10-2013).pdf

2260-delnp-2007-Claims-(26-03-2013).pdf

2260-delnp-2007-claims.pdf

2260-delnp-2007-Correspondence Others-(03-10-2013).pdf

2260-delnp-2007-Correspondence Others-(13-08-2012).pdf

2260-delnp-2007-Correspondence Others-(19-02-2013).pdf

2260-delnp-2007-Correspondence Others-(26-03-2013).pdf

2260-delnp-2007-Correspondence Others-(26-08-2013).pdf

2260-delnp-2007-Correspondence Others-(31-12-2012).pdf

2260-delnp-2007-Correspondence-Others-(04-03-2014).pdf

2260-delnp-2007-Correspondence-Others-(10-07-2013).pdf

2260-delnp-2007-correspondence-others.pdf

2260-delnp-2007-description (complete).pdf

2260-delnp-2007-Form-1-(26-03-2013).pdf

2260-delnp-2007-form-1.pdf

2260-delnp-2007-Form-18-(27-09-2008).pdf

2260-delnp-2007-Form-2-(26-03-2013).pdf

2260-delnp-2007-form-2.pdf

2260-delnp-2007-Form-3-(04-03-2014).pdf

2260-delnp-2007-Form-3-(10-07-2013).pdf

2260-delnp-2007-Form-3-(13-08-2012).pdf

2260-delnp-2007-form-3.pdf

2260-delnp-2007-Form-5-(26-03-2013).pdf

2260-delnp-2007-form-5.pdf

2260-delnp-2007-GPA-(03-10-2013).pdf

2260-delnp-2007-GPA-(26-03-2013).pdf

2260-delnp-2007-GPA-(31-12-2012).pdf

2260-delnp-2007-gpa.pdf

2260-delnp-2007-pct-101.pdf

2260-delnp-2007-pct-210.pdf

2260-delnp-2007-pct-304.pdf


Patent Number 259049
Indian Patent Application Number 2260/DELNP/2007
PG Journal Number 09/2014
Publication Date 28-Feb-2014
Grant Date 24-Feb-2014
Date of Filing 23-Mar-2007
Name of Patentee BAYER PHARMA AKTIENGESELLSCHAFT
Applicant Address MULLERSTRASSE 178, 13353 BERLIN, GERMANY
Inventors:
# Inventor's Name Inventor's Address
1 KLAUS MOHRS WILDSTEIG 24, 42113 WUPPERTAL, GERMANY.
2 MATTHIAS MULLER-GLIEMANN HOLZ 24, 42719 SOLINGEN, GERMANY.
3 JANA LENZ BENZSTR. 7, 42117 WUPPERTAL, GERMANY.
4 WERNER HEILMANN AM RINGOFEN 21, 42327 WUPPERTAL, GERMANY.
5 MICHAEL LOGERS NIEDERRADENBERG 15, 42327 WUPPERTAL, GERMANY.
6 REINHOLD GEHRING WILHELM-BROCKHAUS-WEG 95, 42327 WUPPERTAL, GERMANY.
7 OLIVER KUHN KOPERNIKNSSTR. 49, 67063 LUDWIGSHAFEN, GERMANY.
8 MIKE MATTHAUS FILCHNERWEG 60, 42329 WUPPERTAL, GERMANY.
9 JURGEN STIEHL ROSENSTR. 28, 45549 SPROCKHOVEL, GERMANY.
10 MATHIAS BERWE BRUNSBERGE 10, 45549 SPROCKHOVEL, GERMANY.
PCT International Classification Number C07D 213/81
PCT International Application Number PCT/EP2005/010118
PCT International Filing date 2005-09-20
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 04023131.8 2004-09-29 EUROPEAN UNION