ChEBI: A member of the class of 2-nitrophenols that is phenol in which one of the hydrogens that is ortho to the hydroxy group has been replaced by a nitro group.
2-Nitrophenol is a yellow, crystalline material, moderately toxic, low melting point (45° C). When heated to decomposition 2-Nitrophenol emits toxic fumes of oxides of nitrogen. In molten form violent reaction with strong alkali (85 % potassium hydroxide) [491 M, 1975, p. 342]. Reaction product with chlorosulfuric acid decomposes violently at room temperature [Vervalin, C. H., Hydrocarbon Proc., 1976, 55(9), p. 321].
yellow crystalline solid
Inhalation or ingestion causes headache, drowsiness, nausea, and blue color in lips, ears, and fingernails (cyanosis). Contact with eyes causes irritation. Can be absorbed through the intact skin to give same symptoms as for inhalation.
Crystallise 2-nitrophenol from EtOH/water, water, EtOH, *benzene or MeOH/pet ether (b 70-90o). It can be steam distilled. Petrucci and Weygandt [Anal Chem 33 275 1961] crystallised it from hot water (twice), then EtOH (twice), followed by fractional crystallisation from the melt (twice), drying over CaCl2 in a vacuum desiccator and then in a drying pistol. The 4-nitrobenzoate had m 141o (from EtOH). [Beilstein 6 IV 1246.]
Special Hazards of Combustion Products: Toxic and irritating fumes of unburned material and oxides of nitrogen can form in fire.
manufacture of dyes, paint colorings, rubber chemicals, and fungicides. Indicator in 2% alcohol solution. pH: 5.0 colorless, 7.0 yellow, but the color change is not sharp and cannot be used where CO2 is present; as reagent for glucose.
Air & Water Reactions
Yellow solid. Sinks in and mixes slowly with water.