These common heterocyclic compound, 26621-44-3, name is 3-Nitro-1H-pyrazole, 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. 26621-44-3
Added to a 100mL single-necked flask 3g compound 3 and 18mL acetic acid, stirred, off-white cloudy liquid. Under cold water bath conditions 2.4mL of fuming nitric acid was slowly added dropwise to the mixed solution, maintaining vigorous stirring, turbid liquid becomes yellow, ensure that the reaction temperature does not exceed 30 deg. C. 6mL acetic anhydride was added to the mixture, after dropping, the mixture quickly became clear, dark yellow clear liquid. After the dropwise addition was stirred at room temperature for 3h. After completion of the reaction, the solution was slowly poured into 100mL crushed ice and stirred vigorously, a yellow precipitate was precipitated, filtered to give a white crystalline powder 2.0g, the filtrate was extracted with ethyl acetate to give pale yellow crystals 1.5608g. Yield: 84.7%, recrystallized from n-hexane. Weigh 50mg of compound 4 into thick-walled pressure bottle, and slowly warmed to 140 deg. C, 160 deg. C, 180 deg. C, at this temperature the reaction 1 ~ 3h to give the compound 5, the results shown in Table 2.
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 26621-44-3.