Synthetic Route of 5203-77-0,Some common heterocyclic compound, 5203-77-0, name is 1,3-Dimethyl-1H-pyrazol-5-ol, molecular formula is C5H8N2O, 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.
Weigh 1.7g (0.015mol) 1,3- dimethyl-5-pyrazolone-ol in 250mLthree-necked flask was added 50mL1,2-Dichloroethane was dissolved and weighed 4.0g (0.040mol) oftriethylamine in the system. Under ice cooling, Intermediate (a-2) of1,2-dichloroethane solution (0.010mol (a-2)) was addeddropwise to the system, during the addition using argon. After the reaction 1hThe reaction was followed by HPLC, the reaction was completefeed reaction solution containing intermediate (a-3) a. Counter-containingintermediate (a-3) ofLiquid should be supplemented with 1.0g (0.010mol) oftriethylamine and several drops of acetone cyanohydrin, temperature controlledat 50 ~ 60 and argon gas protectionProtection, response 2h, HPLC trace reaction. Aftercompletion of the reaction was added 100mL of water was slowly added dropwiseHCl, stirring at room temperature, until pH = 3about. 200mL extract was washed with water to remove theaqueous layer, the organic layer was washed twice, dried over anhydrous sodiumsulfate, the organic solvent was removed by rotary evaporation,To give 3.6g a tan solid, a powdered compound a.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1,3-Dimethyl-1H-pyrazol-5-ol, its application will become more common.