Chemical Properties
yellow crystalline solid
Uses
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.
Uses
2-Nitrophenol is a building block used as an acid-base indicator and corrosion inhibitor for aluminum-copper alloy. It is also used to make dyes, paint coloring, rubber chemicals, and substances that kill molds.
Uses
2-Nitrophenol is an intermediate in dyestuff production and a
chemical indicator.
Definition
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of the class of 2-nitrophenols that is phenol in which one of the hydrogens that is ortho to the hydroxy group has been replaced by a nitro group.
Production Methods
2-Chloronitrobenzene in 8.5 % sodium hydroxide solution is heated gradually (exothermic) to 170 ℃ in an autoclave and held there under pressure for 8 h. The resulting solution is cooled and acidified to give the product 2-Nitrophenol in 95 % yield.
General Description
Yellow solid. Sinks in and mixes slowly with water.
Air & Water Reactions
Water insoluble.
Reactivity Profile
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].
Hazard
Toxic by ingestion.
Health Hazard
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.
Fire Hazard
Special Hazards of Combustion Products: Toxic and irritating fumes of unburned material and oxides of nitrogen can form in fire.
Environmental Fate
Biological. A microorganism, Pseudomonas putida, isolated from soil degraded 2-nitrophenol
to nitrite. Degradation by enzymatic mechanisms produced nitrite and catechol. Catechol
subsequently degraded to β-ketoadipic acid (Zeyer and Kearney, 1984). When 2-nitrophenol was
statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater
inoculum, 100% biodegradation with rapid adaptation was achieved after 7 d (Tabak et al., 1981).
In a similar study, 2-nitrophenol degraded rapidly from flooded alluvial and pokkali (organic
matter-rich acid sulfate) soils that were inoculated with parathion-enrichment culture containing 5-
day-old cultures of Flavobacterium sp. ATCC 27551 and Pseudomonas sp. ATCC 29353
(Sudhaker-Barik and Sethunathan, 1978a). 2-Nitrophenol disappeared completely with the
formation of nitrite, particularly in the inoculated soils rather than in the uninoculated soils.
Groundwater. Nielsen et al. (1996) studied the degradation of 2-nitrophenol in a shallow,
glaciofluvial, unconfined sandy aquifer in Jutland, Denmark. As part of the in situ microcosm
study, a cylinder that was open at the bottom and screened at the top was installed through a cased
borehole approximately 5 m below grade. Five liters of water was aerated with atmospheric air to
ensure aerobic conditions were maintained. Groundwater was analyzed weekly for approximately
3 months to determine 2-nitrophenol concentrations with time. The experimentally determined
first-order biodegradation rate constant and corresponding half-life were 0.05/d and 13.86 d,
respectively.
Photolytic. A second-order reaction rate constant of 9 x 10
-13 cm
3/molecule?sec was reported for
the reaction of 2-nitrophenol and OH radicals in the atmosphere (Atkinson, 1985).
Chemical/Physical. Oxidation by Fenton’s reagent (hydrogen peroxide and Fe
3+) produced
nitrohydroquinone and 3-nitrocatechol (Andersson et al., 1986). In an aqueous solution (initial pH
5.0), 2-nitrophenol (100 μM) reacted with Fenton’s reagent (35 μM). After 60-min and 4-h, about
50 and 90% of the 2-nitrophenol was destroyed, respectively. The pH of the solution decreased
due to the formation of nitric acid (Lipczynska-Kochany, 1991).
Purification Methods
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.]
