1H-Pyrazole-4-carboxylic acid, 3-(difluoromethyl)-1-methyl-, ethyl ester

39g (0.0889mol)The halogen-substituted compound product was suspended in 200 g of chloroform, cooled to -25 C with stirring, and 20.5 g (0.178 mol) of 40% methyl hydrazine (MMH) was slowly added dropwise. After the dropwise addition was completed, the reaction was continued for 30 hours. Minutes, warmed to room temperature, separated the aqueous layer, the organic layer, concentrated to dryness, and the residue was recrystallized by adding petroleum ether to obtain 3-fluoroalkyl-1-methylpyrazole-4-carboxylic acid ethyl ester (EDFMPA) (As shown in formula IV) 30.8 g, yield 85%.Add 28.2 g (0.1 mol) of N, N'-diacrylate ethyl piperazine (as shown in Formula I, where R1 is OC2H5), 200 g of chloroform, and 22.2 g (0.22 mol) of triethylamine into the reaction flask. In a temperature controlled range of 10 C to 30 C, 21.5g (0.22mol) of difluoroacetyl fluoride (DFAF) was passed in. After the aeration was completed, the temperature was maintained for 5 hours. After the reaction was completed, 26.8g (0.2mol) of methylhydrazine benzaldehyde hydrazone (BzH) was added dropwise and the temperature was raised to 50 C.Hold the reaction for 3 hours, evaporate the solvent under reduced pressure, remove the residue, add 200 g of chloroform and 5 g of sulfuric acid, and react at room temperature for 8 hours. Add 50 g of water, separate the organic layer, heat up to 60 C, and add a dropwise concentration of 10%. 90g of sodium hydroxide solution. After completion of the dropping, the reaction was continued for 3 hours. After the reaction was completed, the aqueous layer was separated, neutralized with hydrochloric acid dropwise to pH 2, cooled to 10 C, filtered, washed with water, and dried.26 g of 3-fluoroalkyl-1-methyl-1H-pyrazole-4-carboxylic acid (DFMPA) (as shown in Formula V) was obtained, with a total yield of 73.8% and a purity of 99% by HPLC .

Molecular Weight:204.17
XLogP3:1.1
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:4
Exact Mass:204.07103389
Monoisotopic Mass:204.07103389
Topological Polar Surface Area:44.1
Heavy Atom Count:14
Complexity:214
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes