Reference of 26308-42-9,Some common heterocyclic compound, 26308-42-9, name is 3-Ethyl-1-methyl-1H-pyrazole-5-carboxylic acid, molecular formula is C7H10N2O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
To a 50 mL round bottom flask equipped with a magnetic stirrer was added 1-methyl-3-ethyl-1-hydrogen-pyrazole-5-carboxylic acid(154 mg, 1.0 mmol, 1.0 eq),Selectfluor (708 mg, 2.0 mmol, 2.0 eq), lithium acetate (264 mg, 4.0 mmol,4.0 eq); then dichloroethane (3.3 mL) and water (1.7 mL) were added as solvent; the reaction vessel was sealed at 50 C in an oil bathAnd the mixture was heated and stirred for 15 hours. After the reaction was completed, the reaction mixture was extracted twice with 20 mL of ether, and the organic phaseAnd washed with saturated brine, and then dried over anhydrous sodium sulfate. After drying, the organic solvent was dried under reduced pressure to obtain crude productThe crude product was subjected to column separation using analytically pure n-pentane as eluent to give the final product: 1,1′-diethyl-5,5′-difluoro-3,3′-dimethyl-1-hydrogen, 1′-hydro-4,4′-bipyrazole as a colorless oil in 82% yield.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-Ethyl-1-methyl-1H-pyrazole-5-carboxylic acid, its application will become more common.
Reference:
Patent; Central South University; Tang, Zhenyu; Yuan, Xi; Yao, Jianfei; (24 pag.)CN106397377; (2017); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics