26621-44-3

light brown powder

3-Nitro-1H-pyrazole is a pyrazole compound with a nitro functional group, widely used in organic synthesis. The substance can be used in reaction systems such as substitution, nitration or condensation for the preparation of other heterocyclic compounds.

The general procedure for the synthesis of 3-nitro-1H-pyrazole from 1-nitropyrazole is as follows: Step A: 1-nitropyrazole (3.45 g, 30.5 mmol) was mixed with benzonitrile (33 mL) and heated with stirring at 180 °C for 3 hours. Upon completion of the reaction, the mixture was cooled to room temperature, diluted with hexane and stirring was continued for 20 min at room temperature. The precipitated solid was collected by filtration to afford 3-nitro-1H-pyrazole as a tan solid (3.16 g, 91% yield). Product characterization data: 1H NMR (300 MHz, DMSO-d6) δ 13.94 (br s, 1H), 8.03 (d, J = 2.4 Hz, 1H), 7.03 (t, J = 2.4 Hz, 1H).

[1] Archiv der Pharmazie, 1995, vol. 328, # 4, p. 349 - 358
[2] Patent: WO2010/29461, 2010, A1. Location in patent: Page/Page column 63-64
[3] Patent: WO2012/30944, 2012, A2. Location in patent: Page/Page column 97
[4] Patent: US2012/53174, 2012, A1. Location in patent: Page/Page column 45
[5] Patent: WO2012/30924, 2012, A1. Location in patent: Page/Page column 124