Process for the preparation of 3-(3-chloro-1H-pyrazol-1-yl)pyridine

• US 9,580,403 B2
• Filed: 01/06/2016
• Issued: 02/28/2017
• Est. Priority Date: 07/31/2014
• Status: Expired due to Fees

• Current Assignee: Dow Agrosciences LLC (Corteva, Inc.)
• Original Assignee: Dow Agrosciences LLC (Corteva, Inc.)
• Inventors: Li, Xiaoyong, Yang, Qiang, Roth, Gary, Lorsbach, Beth
• Primary Examiner(s): Morris, Patricia L
• Application Number:
  US14/988,773
• Publication Number:
  US 20160152593A1
• Time in Patent Office: 419 Days
• Field of Search: 546/275.4
• US Class Current: 1/1
• CPC Class Codes: C07D 401/04 directly linked by a ring-member-to-ring-member bond

Abstract

3-(3-Chloro-1H-pyrazol-1-yl)pyridine is prepared by cyclizing 3-hydrazinopyridine-dihydrochloride with commercially available 3-ethoxyacrylonitrile to provide 3-(3-amino-1H-pyrazol-1-yl)pyridine, and by converting the amino group to a chloro group by a Sandmeyer reaction.

Claims

1. A process for preparing 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a)

2. The process of claim 1, wherein the alkoxyacrylonitrile is in about a 1.5-fold to about a 2-fold excess.

3. The process of claim 1, wherein the alkoxyacrylonitrile is methoxyacrylonitrile, ethoxyacrylonitrile or propoxyacrylonitrile.

4. The process of claim 3, wherein the alkoxyacrylonitrile is methoxyacrylonitrile.

5. The process of claim 3, wherein the alkoxyacrylonitrile is ethoxyacrylonitrile.

6. The process of claim 3, wherein the alkoxyacrylonitrile is propoxyacrylonitrile.

7. The process of claim 1, wherein the alkali metal (C₁-C₄) alkoxide is sodium ethoxide, and the (C₁-C₄) aliphatic alcohol is ethanol.

8. The process of claim 1, wherein the alkali metal (C₁-C₄) alkoxide is used in about a 2 to about a 5 fold excess.

9. The process of claim 1, wherein the alkali metal (C₁-C₄) alkoxide is neutralized with an acid.