Process for the preparation of 4-{4-[({[4 chloro-3-(trifluoromethyl)phenyl]amino}carbonyl)amino]phenoxy}-N-methylpyridine-2-carboxamide

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 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 the formula (II)

and, in a second step, admixing the compound of the formula (II) 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.

2. A process for preparing the compound of the formula (II),

which comprises reacting the compound of the formula (V)

with 4-chloro-3-trifluoromethylphenyl in a nonchlorinated organic solvent, inert toward 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. isocyanate to give the compound of the formula (II).

3. The process of claim 1 or 2 , wherein the compound of the formula (V) is prepared by reacting the compound of the formula (IV)

with 4-aminophenol without adding a carbonate salt.

4. The process of claim 1 or 2 , 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 of claim 3 , wherein the compound of the formula (IV) is prepared by reacting the compound of the formula (III)

with an aqueous methylamine solution.

6. The process of claim 5 , wherein the compound of the formula (III) is prepared by using a solvent inert toward thionyl chloride, adding thionyl chloride to 2-picolinic acid and without using of dimethylformamide.

7. A process for preparing the compound of the formula (I)

by reacting the compound of the formula (II)

with p-toluenesulfonic acid, which comprises 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 to the mixture.

8. A process for preparing the compound of the formula (I)

by

a) reacting the compound of the formula (IV)

with 4-aminophenol without adding a carbonate salt to give the compound of the formula (V)

b) reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl isocyanate to give the compound of the formula (II)

and

c) reacting the compound of the formula (II) with p-toluenesulfonic acid.

9. A process for preparing the compound of the formula (I)

a) reacting the compound of the formula (III)

with an aqueous methylamine solution to give the compound of the formula (IV)

b) reacting the compound of the formula (IV) with 4-aminophenol to give the compound of the formula (V),

c) reacting the compound of the formula (V) with 4-chloro-3-trifluoromethylphenyl isocyanate to give the compound of the formula (II)

d) reacting the compound of the formula (II) with p-toluenesulfonic acid.

10. A process for preparing the compound of the formula (I)

a) adding thionyl chloride to 2-picolinic acid in a solvent inert toward thionyl chloride without using dimethylformamide and reacting to give the compound of the formula (III)

b) reacting the compound of the formula (III) with methylamine to give the compound of the formula (IV)

c) reacting the compound of the formula (IV) with 4-aminophenol to give the compound of the formula (V)

d) reacting the compound of the formula (V) with 4-chloro-3-trifluoromethyl-phenyl isocyanate to give the compound of the formula (II)

e) reacting the compound of the formula (II) with p-toluenesulfonic acid.

11. The process of claim 1 , wherein p-toluenesulfonic acid monohydrate is used.