Process for the preparation of 5-fluoro-1H-pyrazoles

Patent metadata

Field	Value
Publication number	US-9302994-B2
Application number	US-201314414254-A
Country	US
Kind code	B2
Filing date	Jul 17, 2013
Priority date	Jul 19, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A new process for the preparation of 5-fluoro-1H-pyrazoles of the general formula (I)

is described, resulting from the reaction of an olefin of the general formula (II)

with hydrazines of the formula (III)

R 1 —NH—NH 2   (III),

wherein

R 1 is selected from C 1 -C 6 alkyl, C 5 -C 10 aryl;

R 2 is a trihalomethyl moiety with at least one fluorine atom; and

R 3 is selected from C 1 -C 5 haloalkyl, CF 3 , C 2 F 5 , C 3 F 7 , CF 2 CF 2 Cl, CFClCF 3 ,

in the presence of water and a base.

First claim

The invention claimed is:

1. A process for synthesis of 5-fluoro-1H-pyrazole of formula (I)

comprising reacting an olefin of formula (II)

with a hydrazine of formula (III)
R 1 —NH—NH 2   (III),

wherein
R 1 is selected from C 1 -C 6 alkyl;…

Assignees

• Bayer Cropscience Ag

Inventors

• Pazenok Sergii
• Lui Norbert
• Timoshenko Vadim Mikhailovich
• Kaminskaya Elena Ivanovna
• Shermolovich Yuriy Grigoverievich

Classifications

• C07D231/16 Primary

  Chemistry & Metallurgy · mapped topic