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.

Abstract: Provided are a preparation method for synthesizing a pyrazolecarboxylic acid derivative of the following formula (I), which is suitable for industrial production, and an intermediate as shown by the following formula (II). The method is high in reaction yield in each step, low in waste gas and waste water and low in cost, and requires no special reaction equipment.

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.