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Process for the manufacture of 2,3-dichloropyridine

A technology of dichloropyridine and chloropyridine, applied in the field of preparation of 2,3-dichloropyridine, which can solve the problems of limited scale limitation and low yield

Active Publication Date: 2007-02-07
FMC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the utility of the reported method is severely limited due to low yield (about 45%) and limited scale (about 1 g)

Method used

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  • Process for the manufacture of 2,3-dichloropyridine
  • Process for the manufacture of 2,3-dichloropyridine
  • Process for the manufacture of 2,3-dichloropyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach A

[0024] Embodiment A. Process for the preparation of 2,3-dichloropyridine 1 (Process A),

[0025]

[0026] Including the following steps:

[0027] (1) contacting a solution comprising 3-amino-2-chloropyridine 2 with a first aqueous solution comprising hydrochloric acid to form 3-amino-2-chloropyridine hydrochloride;

[0028]

[0029] (2) contacting the 3-amino-2-chloropyridine hydrochloride with an aqueous solution comprising nitrite to form a diazonium salt; and

[0030] (3) Contacting the diazonium salt with an aqueous solution comprising a Cu(II) salt in the presence of a second aqueous solution comprising hydrochloric acid, optionally in the presence of an organic solvent, to form 2,3-dichloropyridine 1 .

Embodiment approach 1

[0031] Embodiment 1. The method of Embodiment A wherein the nitrite is sodium nitrite.

Embodiment approach 2

[0032] Embodiment 2. The method of Embodiment A wherein the Cu(II) salt is copper(II) chloride or copper(II) oxide.

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Abstract

A method for preparing 2,3-dichloropyridine is disclosed in which 3-amino-2-chloropyridine is contacted with an alkali metal nitrite in the presence of aqueous hydrochloric acid to form a diazonium salt; and the diazonium salt is subsequently decomposed in the presence of copper catalyst wherein at least about 50% of the copper is the copper(II) oxidation state.

Description

technical field [0001] There is a need for efficient and practical methods of preparing 2,3-dichloropyridines. 2,3-Dichloropyridine is an important raw material for the preparation of crop protection agents, pharmaceuticals and other fine chemicals. Background technique [0002] H.J.den Hertog et al., in Recl.Trav.Chim.Pays-Bas, 1950,69,673, reported the preparation of 2,3-dichloropyridine from 3-amino-2-chloropyridine by Gatterman reaction, wherein copper powder Used as a catalyst. However, the utility of the reported method is severely limited due to low yield (about 45%) and limited scale (about 1 g). Contents of the invention [0003] The present invention relates to a kind of method for preparing 2,3-dichloropyridine 1, [0004] [0005] Including the following steps: [0006] (1) contacting 3-amino-2-chloropyridine 2 or a solution comprising 3-amino-2-chloropyridine 2 with hydrochloric acid to form 3-amino-2-chlo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/61C07D213/73C07D213/82
CPCC07D213/73C07D213/61C07D213/82A61K31/4402A61K31/4406
Inventor 拉斐尔·夏皮罗
Owner FMC CORP
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