Process for preparing 2-amino-4-(haloalkyl) pyridine derivatives by cyclizing suitable nitrile precursors with nitrogen compounds

1. A process for preparing 2-aminopyridine derivative of the general formula II comprising reacting an open-chain nitrile precursor I or III with a nitrogen compound in a cyclization reaction:

where the substituents R 1 to R 6 and R f are each defined as follows:

R f : C n H (2n+1−m) X m

X: F, Cl, Br, where X is identical or different when m>1

n: positive integer from 1 to 4;

m: positive integer from 1 to 2n+1

R 1 : hydrogen, C1-C4-alkyl, or C6-aryl,

R 2 : hydrogen or a protecting group for alcohols

R 3 ,R 6 : C1-C4-alkyl,

R 4 ,R 5 : hydrogen,

R: C1-C8-alkyl, C6-C14-aryl, C1-C13-heteroaryl.

2. A process according to claim 1 , wherein the cyclization reaction comprises reacting the enol ether open-chain nitrile precursor I.

3. A process according to claim 2 , wherein said process further comprises forming the enol ether open-chain nitrile precursor I by reacting ketone IV with metallated acetonitrile or a metallated acetonitrile derivative according to the following reaction scheme:

where

M is Li, Na, K, MgY, Mg 0.5 , CaY, Ca 0.5 , ZnY, Zn 0.5 , CdY, Cd 0.5 , Cu, TiY 3

and

Y is X or I, OR, O—CO—R.

4. A process according to claim 1 , wherein R 2 is hydrogen.

5. A process according to claim 1 , wherein the R f radical is trifluoromethyl.

6. A process according to claim 1 , wherein the nitrogen compound is an amine.

7. A process according to claim 1 , wherein the nitrogen compound is ammonia.