Reference of 277299-70-4, A common heterocyclic compound, 277299-70-4, name is 2-(3,4-Dimethylphenyl)-5-methyl-1H-pyrazol-3(2H)-one, molecular formula is C12H14N2O, its 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.
200 ml of 2 mol/L hydrochloric acid was added to the reaction vessel.750ml of ethanol,50 g (0.26 mol) of 2-amino-6-bromophenol,Stir well,Cool down to 0 ~ 10 C,Slowly add sodium nitrite solution [18g (0.26mol) sodium nitrite dissolved in 50ml water],Temperature control does not exceed 10 C,Completion of the dropwise addition, the reaction at 5 ~ 10 1.5 ~ 2h,The reaction solution was allowed to rise to room temperature.Add triethylamine to adjust the pH of the reaction solution to 7-8.Further, 54 g (0.26 mol) of the compound of the formula (III) is added.The reaction was continued at 20 to 30 C for 2 hours.At the end of the reaction, the pH of the reaction solution was adjusted to 1-2 with 2 mol/L hydrochloric acid, the solid was precipitated, filtered, and the filter cake was washed with a mixture of ethanol/water (1:1), and the filter cake was dried under vacuum at 45 C.A dark red solid was obtained in 104.5 g (IV), yield 98%, and purity 99.562%.
The synthetic route of 277299-70-4 has been constantly updated, and we look forward to future research findings.