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Neopentyl glycol is synthesized industrially by the aldol reaction of formaldehyde and isobutyraldehyde. This creates the intermediate hydroxypivaldehyde, which can be converted to neopentyl glycol by either a Cannizzaro reaction with excess formaldehyde, or by hydrogenation using palladium on carbon. [2]
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl (C=O) functional group by formaldehyde (H−CHO) and a primary or secondary amine (−NH 2) or ammonia (NH 3). [1] The final product is a β-amino-carbonyl compound also known as a Mannich base.
The reaction is catalyzed by nucleophiles such as a cyanide or an N-heterocyclic carbene (usually thiazolium salts). The reaction mechanism was proposed in 1903 by A. J. Lapworth . [ 7 ] In the first step in this reaction, the cyanide anion (as sodium cyanide ) reacts with the aldehyde in a nucleophilic addition .
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 ...
Formaldehyde inhaled at this concentration may cause headaches, a burning sensation in the throat, and difficulty breathing, and can trigger or aggravate asthma symptoms. [70] [71] The CDC considers formaldehyde as a systemic poison. Formaldehyde poisoning can cause permanent changes in the nervous system's functions. [72]
In organic synthesis, the Casiraghi formylation is the formation of a salicylaldehyde from a phenol and paraformaldehyde.The reaction requires a strong Brønsted base and a weak Lewis acid, and gives a methanol coproduct: [1]
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.
Cannizzaro's chemical interests had originally centered on natural products and on reactions of aromatic compounds; in 1853 he discovered that when benzaldehyde is treated with concentrated base, both benzoic acid and benzyl alcohol are produced—a phenomenon known today as the Cannizzaro reaction. In his 1858 pamphlet, Cannizzaro showed that ...