phenol are weakly acidic and turn blue litmus slightly to red. Phenol is neutralized by sodium hydroxide forming sodium phenate or phenolate, but being weaker than carbonic acid, it cannot be neutralized by sodium bicarbonate or sodium carbonate to liberate carbon dioxide. C6H5OH + NaOH -> C6H5ONa + H2O When a mixture of phenol and benzoyl chloride are shaken in presence of dilute sodium hydroxide solution, phenyl benzoate is formed. This is an example of the Schotten–Baumann reaction: C6H5COCl + HOC6H5 -> C6H5CO2C6H5 + HCl Phenol is reduced to benzene when it is distilled with zinc dust or when its vapour is passed over granules of zinc at 400 °C: C6H5OH + Zn -> C6H6 + ZnO When phenol is treated with diazomethane in the presence of boron trifluoride (), anisole is obtained as the main product and nitrogen gas as a byproduct. C6H5OH + CH2N2 -> C6H5OCH3 + N2 When phenol reacts with iron(III) chloride solution, an intense violet-purple solution is formed. Production Because of phenol's commercial importance, many methods have been developed for its production, but the cumene process is the dominant technology. Cumene process Accounting for 95% of production (2003) is the cumene process, also called Hock process. It involves the partial oxidation of cumene (isopropylbenzene) via the Hock rearrangement: Compared to most other processes, the cumene process uses relatively mild conditions and relatively inexpensive raw materials. For the process to be economical, both phenol and the acetone by-product must be in demand. In 2010, worldwide demand for acetone was approximately 6.7 million tonnes, 83 percent of which was satisfied with acetone produced by the cumene process. A route analogous to the cumene process begins with cyclohexylbenzene. It is oxidized to a hydroperoxide, akin to the production of cumene hydroperoxide. Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone. Cyclohexanone is an important precursor to some nylons. Oxidation of benzene and toluene The direct oxidation of benzene () to phenol is theoretically possible and of great interest, but it has not been commercialized: C6H6 + O -> C6H5OH Nitrous oxide is a potentially "green" oxidant that is a more potent oxidant than O2. Routes for the generation of nitrous oxide however remain uncompetitive. An electrosynthesis employing alternating current gives phenol from benzene. The oxidation of toluene, as developed by Dow Chemical, involves copper-catalyzed reaction of molten sodium benzoate with air: C6H5CH3 + 2 O2