Method for producing pyrazole compound

摘要

A method for producing a pyrazole compound of the general formula (5) includes reacting a 2-acyl-3-aminoacrylic acid ester of the general formula (1) with a hydrazine of the general formula (4) in the presence of a base;
where R1, R2, R3 and R4 each independently represent an alkyl group
;
wherein R5 represents an alkyl group or an aryl group
;
wherein R1, R4 and R5 have the same meanings as above.
;It is possible by this production method to produce the 1,3-disubstituted pyrazol-4-carboxylic acid ester at a high yield and selectivity and with less discoloration.

主权项

1. A method for producing a pyrazole compound of the general formula (5), comprising:
a first reaction step of obtaining a reactor content containing a 2-acyl-3-aminoacrylic acid ester of the general formula (1) by reaction of difluoroacetic acid fluoride with a dialkylaminoacrylic acid ester of the general formula (3) in the presence of an organic base; and
a second reaction step of forming the pyrazole compound of the general formula (5) by mixing the reactor content obtained by the first reaction step with a substituted hydrazine of the general formula (4) and an inorganic base where R1, R2, R3 and R4 each independently represent an alkyl group where R2, R3 and R4 have the same meanings as in the general formula (1) wherein R5 represents an alkyl group or an aryl group wherein R1, R4 and R5 have the same meanings as above.