Process for the preparation of 4-alkoxy-3-hydroxypicolinic acids

Patent metadata

Field	Value
Publication number	US-9718783-B2
Application number	US-201615339190-A
Country	US
Kind code	B2
Filing date	Oct 31, 2016
Priority date	Jul 8, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

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. 4-Alkoxy-3-hydroxypicolinic acids may be conveniently prepared from 4,6-dibromo-3-hydroxypicolinonitrile in a series of chemical steps selected from bromo substitution, nitrile hydrolysis and halogen reduction.

First claim

What is claimed is:

1. A process for preparing the compound of Formula H

comprises the steps of:
a) creating a mixture which includes the compound of Formula F,

wherein R 1 is a C 1 -C 3 alkyl;
a strong base, zinc metal, and water;
b) heating the mixture; and
c) isolating the compound of Formula H from the mixture.

Assignees

• Dow Agrosciences Llc

Inventors

• Renga James M
• Zhu Yuanming
• Whiteker Gregory T
• Choy Nakyen
• Stockman Kenneth E

Classifications

• C07D213/803 Primary

  Processes of preparation · CPC title

• C07D213/84 Primary

  Nitriles · 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

• C07D213/79

  Acids; Esters · CPC title

• C07D213/54

  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