Reference of 16034-46-1,Some common heterocyclic compound, 16034-46-1, name is 1-Methyl-1H-pyrazole-5-carboxylic acid, molecular formula is C5H6N2O2, 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.
Oleum (1977mmol) is slowly added to fuming nitric acid (777 mmol) followed by the addition of 2-methyl-2H-pyrazole-3-carboxylic acid (277 mmol) in small portions maintaining the reaction temperature below 6O0C. Stirring at this temperature is then continued for a further 1 h. On completion, the reaction mixture is poured onto crushed ice and extracted with ethyl acetate (300 mL x 3). The combined organic phases are washed with water (250 mL x 2) and dried over anhydrous sodium sulfate. The solvent is removed under reduced pressure to afford 2-methyl-4-nitro-2H-pyrazole-3- carboxylic acid as a light yellow solid. Compound wt: 23.6g, 50%.[00251] 1H NMR (400 MHz, OMSO-d6) delta: 8.29 (lH,s); 3.95 (3H, s).
The synthetic route of 16034-46-1 has been constantly updated, and we look forward to future research findings.