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Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium hydroxide or potassium hydroxide , giving the sodium or potassium carboxylate salt of the carboxylic ...
Benzaldehyde undergoes disproportionation upon treatment with concentrated alkali (Cannizzaro reaction): one molecule of the aldehyde is reduced to the benzyl alcohol and another molecule is simultaneously oxidized to benzoic acid. With diols, including many sugars, benzaldehyde condenses to form benzylidene acetals.
In the classic example, benzaldehyde is converted to benzoin (PhCH(OH)C(O)Ph). [3] The benzoin condensation was first reported in 1832 by Justus von Liebig and Friedrich Wöhler during their research on bitter almond oil. [4] The catalytic version of the reaction involving cyanide was developed by Nikolay Zinin in the late 1830s. [5] [6 ...
Stanislao Cannizzaro FRS (/ ˌ k æ n ɪ ˈ z ɑːr oʊ / KAN-iz-AR-oh, [1] also US: /-ɪ t ˈ s ɑːr-/-it-SAR-, [2] Italian: [staniˈzlaːo kannitˈtsaːro]; 13 July 1826 – 10 May 1910) was an Italian chemist. He is famous for the Cannizzaro reaction and for his influential role in the atomic-weight deliberations of the Karlsruhe ...
Another route entails hydrogenation of benzaldehyde, a by-product of the oxidation of toluene to benzoic acid. [ 5 ] For laboratory use, Grignard reaction of phenylmagnesium bromide (C 6 H 5 MgBr) with formaldehyde and the Cannizzaro reaction of benzaldehyde also give benzyl alcohol.
The reaction is named after Russian organic chemist Vyacheslav Tishchenko, who discovered that aluminium alkoxides are effective catalysts for the reaction. [1] [2] [3] In the related Cannizzaro reaction, the base is sodium hydroxide and then the oxidation product is a carboxylic acid and the reduction product is an alcohol.
Aside from the inherent reversibility of the reaction (or "retro–Henry") that can prevent the reaction from proceeding, the β-nitro alcohol also has the potential to undergo dehydration. For sterically hindered substrates, it is also possible for a base-catalyzed self-condensation (Cannizzaro reaction) to occur. A general scheme of the ...
para-Dimethylaminobenzaldehyde is an organic compound containing amine and aldehyde moieties which is used in Ehrlich's reagent and Kovac's reagent to test for indoles.The carbonyl group typically reacts with the electron rich 2-position of the indole but may also react at the C-3 or N-1 positions. [2]