Add 4.5 g (0.05 mol) of 2-nitropropane and 9 mL of a 6 mol/L sodium hydroxide solution to a 100 mL three-necked flask. The reaction was stirred magnetically for 0.5 h in an ice-water bath, and 4 g (0.025 mol) of liquid bromine was added dropwise to the flask using a constant pressure dropping funnel. After the dropwise addition was completed, 15 mL of absolute ethanol was added to thereto, and stirring was continued in an ice bath for 0.5 h. Then the ice bath was removed, the temperature was raised to 90℃, and the reaction was refluxed for 2 hours to stop the reaction. After the reaction liquid was naturally cooled to room temperature, a large amount of white solid precipitated, filtered, washed several times with absolute ethanol and distilled water, and dried under vacuum to obtain 40.13 g of white flake crystals. The yield was 91.2%.