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Formaldehyde (/ f ɔːr ˈ m æ l d ɪ h aɪ d / ⓘ for-MAL-di-hide, US also / f ə r-/ ⓘ fər-) (systematic name methanal) is an organic compound with the chemical formula CH 2 O and structure H−CHO, more precisely H 2 C=O.
Reactions between aldimines and α-methylene carbonyls are also considered Mannich reactions because these imines form between amines and aldehydes. The reaction is named after Carl Mannich. [2] [3] Scheme 1 – Ammonia or an amine reacts with formaldehyde and an alpha acidic proton of a carbonyl compound to a beta amino carbonyl compound.
The Eschweiler–Clarke reaction (also called the Eschweiler–Clarke methylation) is a chemical reaction whereby a primary (or secondary) amine is methylated using excess formic acid and formaldehyde. [1] [2] Reductive amination reactions such as this one will not produce quaternary ammonium salts, but instead will stop at the tertiary amine ...
The direct reaction between phenol and paraformaldehyde is possible via the Casiraghi formylation, [4] but other methods apply masked forms of formaldehyde, in part to limit the formation of phenol formaldehyde resins. Aldehydes are strongly deactivating and as such phenols typically only react once.
The formose reaction is of importance to the question of the origin of life, as it leads from simple formaldehyde to complex sugars like ribose, a building block of RNA.In one experiment simulating early Earth conditions, pentoses formed from mixtures of formaldehyde, glyceraldehyde, and borate minerals such as colemanite (Ca 2 B 6 O 11 5H 2 O) or kernite (Na 2 B 4 O 7). [6]
The ion-permeable ion-exchange membrane at the center of the cell allows only the sodium ions (Na +) to pass to the second chamber where they react with the hydroxide ions to produce caustic soda (NaOH) (B in figure): [1] Na + + OH − → NaOH The overall reaction for the electrolysis of brine is thus: 2NaCl + 2 H 2 O → Cl 2 + H 2 + 2NaOH
The reaction of an organic substrate with phosgene is called phosgenation. [9] Phosgenation of diols give carbonates (R = H, alkyl, aryl), which can be either linear or cyclic: n HO−CR 2 −X−CR 2 −OH + n COCl 2 → [−O−CR 2 −X−CR 2 −O−C(=O)−] n + 2n HCl. An example is the reaction of phosgene with bisphenol A to form ...
In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX 3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C(=O)CH 3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a base.