Process for the preparation of 3-(3-chloro-1H-pyrazol-1-yl)pyridine
US-9115115-B1 · Aug 25, 2015 · US
Process for the preparation of 3-(3-chloro-1H-pyrazol-1-yl)pyridine
US9611247B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9611247-B2 |
| Application number | US-201514848867-A |
| Country | US |
| Kind code | B2 |
| Filing date | Sep 9, 2015 |
| Priority date | Jul 31, 2014 |
| Publication date | Apr 4, 2017 |
| Grant date | Apr 4, 2017 |
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Abstract
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3-(3-Chloro-1H-pyrazol-1-yl)pyridine is prepared by cyclizing 3-hydrazinopyridine-·dihydrochloride with acrylonitrile to provide 1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazol-3-amine, by oxidizing to provide 3-(3-amino-1H-pyrazol-1-yl)pyridine, and by converting the amino group to a chloro group by a Sandmeyer reaction.
First claim
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What is claimed is: 1. A process for preparing diazonium salt (8b) comprising treating 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a) with aqueous hydrochloric acid and sodium nitrite at a temperature of about 0° C. to about 25° C. 2. The process of claim 1 , wherein the aqueous hydrochloric acid is used in excess. 3. The process of claim 1 , wherein the sodium nitrite is used in about a 1.3-fold to about a 2-fold excess. 4. A process for preparing 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b), comprising treating diazonium salt (8b) with copper chloride at a temperature of about 0° C. to about 25° C. 5. The process of claim 4 , wherein the copper chloride is in an amount of about 5 mole percent to about 60 mole percent. 6. The process of claim 4 , wherein the copper chloride is copper (I) chloride or copper (II) chloride. 7. The process of claim 6 , wherein the copper chloride is copper (I) chloride. 8. The process of claim 6 , wherein the copper chloride is copper (II) chloride. 9. The process of claim 4 , wherein a water immiscible organic solvent is added in to suppress foaming. 10. The process of claim 9 , wherein the water immiscible solvent is toluene.
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- C07D401/04Primary
directly linked by a ring-member-to-ring-member bond · CPC title
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- What does patent US9611247B2 cover?
- 3-(3-Chloro-1H-pyrazol-1-yl)pyridine is prepared by cyclizing 3-hydrazinopyridine-·dihydrochloride with acrylonitrile to provide 1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazol-3-amine, by oxidizing to provide 3-(3-amino-1H-pyrazol-1-yl)pyridine, and by converting the amino group to a chloro group by a Sandmeyer reaction.
- Who is the assignee on this patent?
- Dow Agrosciences Llc
- What technology area does this patent fall under?
- Primary CPC classification C07D401/04. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Tue Apr 04 2017 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 12 related publications on this page (citations in our corpus or others sharing the same primary CPC).