Related Products of 3994-50-1, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 3994-50-1, name is 1-Methyl-4-nitro-1H-pyrazole belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.
At room temperature, pyrazole (0.2 mol) was dissolved in concentrated sulfuric acid (50 mL) and slowly raised to a temperature of 60 CConcentrated nitric acid (9.2 mL) was added and stirring was continued at 60 C for 1.5 hours.After completion of the reaction, the reaction solution was poured into 600 g of ice water, and the resulting white solid was separated by filtration and washed with water.After extraction with ethyl acetate (100 mL x 3), the organic phase was washed successively with 1% sodium bicarbonate solution (100 mL), water (100 mL) and physiological saline (100 mL), dried over anhydrous sodium sulfate and filtered, Finally, the organic phase liquid was rotary evaporated to give a white solid which was combined with the previously obtained white solid to give compound 2a. The resulting compound 2a (12 mmol) was dissolved in DMSO (9 mL)And potassium carbonate (10.9 mmol) was added successively thereto,Methyl iodide (6 mmol),8-hydroxyquinoline (1 mmol),CuI (0.58 mmol). Argon under the conditions of protection, stirMixed and heated to 130 C,After 20 hours of reaction,The reaction solution was poured into an appropriate amount of water,The resulting green solid was separated by filtration.The mother liquor was extracted with ethyl acetate (100 mL x 3). Finally, the organic phase liquid was evaporated to dryness and the resulting crude product was combined with the previously obtained green solid and purified by silica gel column chromatography to obtain Compound 4a. Compound 4a (1 mmol), hydrazine hydrate (0.5 mL) was added to ethanol (1 mL) and palladium on carbon (0.02 g) was added as catalyst.Heated at 80 C and refluxed for 10 minutes. After the completion of the reaction, the resulting mother liquor was subjected to rotary evaporation and drying to obtain Compound 5a. Compound 4a (1 mmol), hydrazine hydrate (0.5 mL) was added to ethanol (1 mL) and palladium on carbon (0.02 g) was added as catalyst.Heated at 80 C and refluxed for 10 minutes. After the completion of the reaction, the resulting mother liquor was subjected to rotary evaporation and drying to obtain Compound 5a. The compound 8a (1 mmol),EDC (1 mmol), HOBt (1 mmol) was added to DMF(3 mL) for 30 min.The compound 5a, DMAP (1 mmol), triethylamine (500 [mu] L) were added to the activated DMFSolution. At room temperature, stir overnight.After completion of the reaction, 100 mL of saturated sodium chloride solution was added to the reaction solution, and the mixture was washed with ethyl acetateEster extraction (200 mL x 3) extraction. Finally, the organic phase liquid was evaporated under vacuum and evaporated to dryness to obtain a crude product, using a silica gel columnSeparation and purification to give the final compound 9a to give a white solid powder in a yield of 86.4%
The synthetic route of 1-Methyl-4-nitro-1H-pyrazole has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Nanjing University; Zhu Hailiang; Shi Lu; Wang Zefeng; Wang Chenru; (14 pag.)CN107098861; (2017); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics