Ethyl1,3-dimethylpyrazole-5-carboxylate

Colorless to light yellow liqui

0.1 mol of 3-methyl-5-pyrazolecarboxylic acid ethyl ester, 0.055 mol of dimethyl carbonate (DMC), 100 mL of xylene and 2.0 gCs2CO3, 130 ~ 140 reaction 8h; reaction Bi, cooled to room temperature, spin off the solvent, the oil-like 1, 3-dimethyl-5-pyrazole formate, by liquid chromatography quantitative analysis of 97.7percent Yield 85.8percent.3-methylpyrazole-5-carboxylic acid ethyl ester (65 mmol) and dimethyl sulfate (78 mmol) in N, N-dimethylformamide , 120 mL) and stirred at 60-70 ° C for 2-4 hours. The reaction solution was cooled and extracted with ethyl acetate. The resulting organic phase was washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the title compound 9. 0. g.In a reactor equipped with a rectification device, 92.4 g (0.55 mol) of ethyl 1, 3-dimethyl-5-pyrazolecarboxylic acid and 95 g (0.55 mol) of p-tert-butylbenzoacetonitrile were charged, Toluene was used as a solvent. After dehydration under reflux, 224g (0.66mol) of sodium ethoxide solution was added dropwise, The addition was completed within 5 hours, and low-boiling by-products were separated from the top of the column.After the reaction is completed, the solvent and other boilables are distilled off under reduced pressure.Toluene is recyclable.Add anhydrous acetonitrile and 4.5 g (0.03 mol) of sodium iodide to the reactor, 87 g (0.57 mol) of 1-chloroethyl ethyl carbonate was slowly added dropwise under reflux, and the addition was completed within 2 h. After the reaction is completed, cool and separate the liquid phase.Distill off the solvent, 209 g of 1- (2- (4- (tert-butyl) phenyl) -2-cyano-1- (1-ethyl-3-methyl-1H-5-pyrazolyl) ethoxy) ethoxy Ethyl carbonate, The yield was 92.5%, of which the E-form content was 89%.In a reactor equipped with a distillation device, add toluene, 92.4 g (0.55 mol) of ethyl 1, 3-dimethyl-5-pyrazolecarboxylic acid and 95 g (0.55 mol) of p-tert-butylbenzoacetonitrile. After dehydration under reflux, 120 g (0.66 mol) of sodium methoxide solution was added dropwise.The addition was completed within 5 hours, and low-boiling by-products were separated from the top of the column.After the reaction was completed, the solvent and other boilables were distilled off under reduced pressure, and toluene was recovered.Add acetonitrile solvent and 4.5g (0.03mol) sodium iodide to the residue, 102.6 g (0.57 mol) of 1-chloroethyl isobutyl carbonate was added, and the temperature was raised to reflux.After the reaction was completed, the mixture was cooled, the liquid phase was separated, and the solvent was distilled off under reduced pressure.225 g of 1- (2- (4- (tert-butyl) phenyl) -2-cyano-1- (1, 3-dimethyl-1H-5-pyrazolyl) ethenyloxy) ethoxy Isobutyl carbonate, The yield was 93.5%, of which the E-form content was 90%.

Molecular Weight:168.19
XLogP3:1.2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:3
Exact Mass:168.089877630
Monoisotopic Mass:168.089877630
Topological Polar Surface Area:44.1
Heavy Atom Count:12
Complexity:172
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes