Process for the preparation of dibromohydroxypicolinonitrile

Patent metadata

Field	Value
Publication number	US-9522887-B2
Application number	US-201514794430-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 8, 2014
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

4,6-Dibromo-3-hydroxypicolinonitrile may be prepared from furfural in a series of chemical steps selected from cyano-amination, amine salt formation and bromination-rearrangement.

First claim

What is claimed is:

1. A process for the preparation of the compound of Formula A

comprising the steps of:
a) creating a first mixture by combining together in a solvent an ammonia source, a cyanide source and a furan-2-aldehyde of Formula B

b) combining a brominating agent with the first mixture to form a second mixture; and
c) isolating the compound of Formula A from the second mixture.

2. The process of claim 1 wherein the brominating agent is bromine.

3. A process for the preparation of the compound of Formula A

comprising the steps of:
a) creating a first mixture by combining together in a solvent an ammonia source, a cyanide source and a furan-2-aldehyde of Formula B

b) isolating a compound of Formula C from the first mixture;

c) adding a mineral acid to the compound of Formula C to form a second mixture;
d) isolating a compound of Formula D from the second mixture;

wherein X is Br, HSO 4 , NO 3 or H 2 PO 4 ;

e) adding a brominating agent and water to the compound of Formula D to form a third mixture; and
f) isolating the compound of Formula A from the third mixture.

4. The process of claim 3 wherein the mineral acid is hydrobromic acid.

5. The process of claim 3 wherein X is Br.

6. The process of claim 3 wherein the brominating agent is bromine.

7. A process for the preparation of a compound of Formula A

comprising the steps of:
a) creating a mixture by combining together a brominating agent, water and a compound of Formula D

wherein X is Br, HSO 4 , NO 3 or H 2 PO 4 ; and

b) isolating the compound of Formula A from the mixture.

8. The process of claim 7 wherein X is Br.

9. The process of claim 7 wherein the brominating agent is bromine.

10. A process for the preparation of the compound of Formula A

which comprises the following steps:
a) creating a first mixture by combining together a brominating agent, water and the compound of Formula D

wherein X is Br, HSO 4 , NO 3 or H 2 PO 4 ;

b) isolating the compound of Formula J from the first mixture

c) creating a second mixture by combining a brominating agent and the compound of Formula J; and
d) isolating the compound of Formula A from the second mixture.

11. The process of claim 10 wherein X is Br.

12. The process of claim 10 wherein the brominating agent is bromine.

Assignees

• Dow Agrosciences Llc

Inventors

• Renga James M
• Zhu Yuanming
• Whiteker Gregory T
• Choy Nakyen

Classifications

• C07D213/803 Primary

  Processes of preparation · CPC title

• C07D213/84 Primary

  Nitriles · CPC title

• C07D213/79

  Acids; Esters · CPC title

• C07D307/54

  Radicals substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals · CPC title

• A61K31/44

  Non condensed pyridines; Hydrogenated derivatives thereof · CPC title