nitrobenzene, C6H5NO2, very poisonous, flammable, pale yellow, liquid aromatic compound with an odor like that of bitter almonds. It is sometimes called oil of mirbane or nitrobenzol. Nitrobenzene melts at 5.85°C, boils at 210.9°C, is only slightly soluble in water, but is very soluble in ethanol, ether, and benzene. It is prepared by treating benzene with a mixture of nitric and sulfuric acids; in the resulting nitration reaction, one hydrogen in the benzene molecule is replaced with a nitro group, NO2. The major use of nitrobenzene is in the production of aniline, commercially the most important amine; nitrobenzene is heated with iron and dilute hydrochloric acid, and the resulting anilinium chloride is treated with sodium carbonate to release aniline. In the pharmaceutical industry nitrobenzene is used in the production of the analgesic acetaminophen, or paracetamol. Nitrobenzene is also used in shoe and floor polishes, leather dressings, and paint solvents to mask unpleasant odors. As oil of mirbane, nitrobenzene was used as an inexpensive perfume for soaps and cosmetics but is now considered too toxic for such applications.
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