These common heterocyclic compound, 7119-95-1, name is 1-Nitropyrazole, 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. HPLC of Formula: C3H3N3O2
Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of 1-nitropyrazole (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-800C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-nitropyrazole (16 g); 1H NMR: (DMSOd6 + CF3CO2H) 8.57 (s, 2H).
The synthetic route of 1-Nitropyrazole has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2007/99317; (2007); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics