Search results
Results From The WOW.Com Content Network
Formaldehyde is readily oxidized by atmospheric oxygen into formic acid. For this reason, commercial formaldehyde is typically contaminated with formic acid. Formaldehyde can be hydrogenated into methanol. In the Cannizzaro reaction, formaldehyde and base react to produce formic acid and methanol, a disproportionation reaction.
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.
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.
an amine with formaldehyde and a carbonyl compound in the Mannich reaction; an enolate ion in an aldol reaction or Baylis–Hillman reaction; an organometallic nucleophile in the Grignard reaction or the related Barbier reaction or a Reformatskii reaction
Silver bromide (AgBr). Nearly all elements in the periodic table form binary bromides. The exceptions are decidedly in the minority and stem in each case from one of three causes: extreme inertness and reluctance to participate in chemical reactions (the noble gases, with the exception of xenon in the very unstable XeBr 2; extreme nuclear instability hampering chemical investigation before ...
A classic example is the reaction of salicylic acid with a mixture of nitric and sulfuric acid to form picric acid. The nitration of the 2 position involves the loss of CO 2 as the leaving group. Desulfonation in which a sulfonyl group is substituted by a proton is a common example. See also Hayashi rearrangement.
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.
A common method for hydroxymethylation involves the reaction of formaldehyde with active C-H and N-H bonds: R 3 C-H + CH 2 O → R 3 C-CH 2 OH R 2 N-H + CH 2 O → R 2 N-CH 2 OH. A typical active C-H bond is provided by a terminal acetylene [1] or the alpha protons of an aldehyde. [2]