US 10,556,868 B2Granted

Method for synthesizing 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid and intermediates thereof

AssigneeZhejiang Yongtai Technology Co., Ltd.

InventorsRenbao He, Yingmei Wang, Hongming Shao, Yizhong Jin

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Abstract

The present invention relates to a method for synthesizing a compound of 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid, wherein including the steps of: (A) the diethyl ester compounds represented by the following Formula IV are reacted under the action of amine, alkali and carbonyl reagents to produce the acrylic diester compound represented by the following Formula I, wherein: (B) the above compound represented by the Formula I is reacted with a fluoride reagent, a Lewis acid and a methyl hydrazine to form a pyrazole ring-containing diester compound represented by the Formula II, (C) the heterocyclic-containing diester compound represented by the Formula II is reacted with a base to give 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid represented by the Formula III.

Claims11

Dependent claims

A method for synthesizing 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid represented by the following Formula III,

comprising the steps of:
(A) a diethyl ester compound represented by the following Formula IV is reacted under the action of an amine, a base and a carbonylating agent to form an acrylic diester compound represented by the following Formula I,
wherein,
wherein the definition of R1 is the same as above;
(B) the above compound represented by the Formula I is reacted with a fluoride reagent, a Lewis acid and a methyl hydrazine to form a pyrazole ring-containing diester compound represented by the following Formula II,
wherein the definition of R1 is the same as above:
(C) a heterocyclic-containing diester compound represented by the Formula II is reacted with a base to form the 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid represented by the Formula III.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/325,717Filed 29 Sep 2016
Priority: CN 2016 1 066826615 Aug 2016
Published: US 2019/0202791 A14 Jul 2019
Granted: 11 Feb 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

C07D 231/28
With hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals,…:…
C07D 231/14
Having two or three double bonds between ring members or between ring members and non-ring members: with hetero atoms or with carbon atoms having…
C07D
Heterocyclic compounds