# US 7,608,720 B2 · Process for the preparation on 2-aminomethylpyridine derivatives

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- Number: US 7,608,720 B2
- Document ID: US7608720B2
- Status: Granted
- Kind: B2
- Application number: 10/554,880
- Filed: 2004-04-26
- Published: 2006-10-19
- Granted: 2009-10-27
- Earliest claimed: 2003-04-28
- Assignees: Bayer CropScience AG
- Inventors: Jorn Stolting; Brian Burton
- Web page: https://patentgrep.com/patent/US7608720B2

## CPC

- C07D 213/38: having only hydrogen or hydrocarbon radicals attached to the substituent nitrogen atom
- C07D 213/26: Radicals substituted by halogen atoms or nitro radicals
- C07D 213/61: Halogen atoms or nitro radicals
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The present invention relates to a novel process for the preparation of 2-amino-methylpyridine derivatives of the formula (I), comprising reacting in a first step 2-substituted pyridine derivatives of the formula (II), with a nitroalkane of the formula (III), in the presence of a base resulting in 2-nitromethylpyridine derivatives of the formula (IV) and hydrogenating these 2-nitromethylpyridine derivatives of the formula (IV) in a second step in the presence of a catalyst and in the presence of an acid, where in the formulae n, X, Y, R1, R2 and A are as defined in the description.

## Claims

### Claim 1

A process for the preparation of 2-aminomethylpyridine derivatives of formula (I) or salts thereof
comprising the steps of reacting 2-substituted pyridine derivatives of the formula (II)
with a nitroalkane of the formula (III)
in the presence of a base resulting in 2-nitromethylpyridine derivatives of the formula (IV)
and then hydrogenating these 2-nitromethylpyridine derivatives of the formula (IV) in the presence of a catalyst and an acid,
wherein
n represents 0, 1, 2 or 3,
X represents a halogen atom,
Y is selected from the group consisting of a halogen atom, halogenoalkyl, alkoxycarbonyl, and alkylsulfonyl, where each Y may be identical or different if n represents, 2 or 3,
R1 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, and cycloalkylmethyl,
R2 is selected from the group consisting of hydrogen and alkyl, or
R1 and R2 taken together can represent alkylene, and
A is selected from the group consisting of halogen, trifluoromethylsulfonyl methylsulphonyl, and other radicals that can act as negatively charged leaving groups.

### Claim 2 (depends on 1)

The process of claim 1, where the base is selected from the group consisting of sodium methanolate, sodium ethanolate, potassium tert-butanolate, sodium tert-butanolate, sodium iso-butanolate, sodium hydroxide, and potassium hydroxide.

### Claim 3 (depends on 1)

The process of claim 1 wherein the catalyst is selected from the group consisting of Raney nickel, Raney cobalt, and palladium on carbon.

### Claim 4 (depends on 1)

The process of claim 1 wherein the acid is selected from the group consisting of hydrochloric, sulphuric, phosphoric, formic, acetic, propionic, trifluoroacetic, trichloroacetic, and methanesulphonic acids.

### Claim 5 (depends on 1)

The process of claim 1 wherein the 2-aminomethylpyridine derivative of formula (I) is 3-chloro-2-nitromethyl-5-trifluoromethylpyridine, the 2-substituted pyridine derivative of the formula (II) is 2,3-dichloro-5-trifluoromethylpyridine, the nitroalkane of the formula (III) is nitromethane, and the 2-nitromethylpyridine derivative of the formula (IV) is 3-chloro-2-nitromethyl-5-trifluoromethylpyridine.

### Claim 6 (depends on 5)

The process of claim 5 wherein the base is selected from the group consisting of potassium tert-butanolate and potassium hydroxide.

### Claim 7 (depends on 5)

The process of claim 5 wherein the acid is hydrogen chloride.

### Claim 8 (depends on 6)

The process of claim 6 wherein the acid is hydrogen chloride.

### Claim 9 (depends on 5)

The process of claim 5 wherein the catalyst is palladium on carbon.

### Claim 10 (depends on 6)

The process of claim 6 wherein the catalyst is palladium on carbon.

### Claim 11 (depends on 7)

The process of claim 7 wherein the catalyst is palladium on carbon.

### Claim 12 (depends on 8)

The process of claim 8 wherein the catalyst is palladium on carbon.