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Mechanism for acid-catalyzed hydrolysis of an amide. Upon hydrolysis, an amide converts into a carboxylic acid and an amine or ammonia (which in the presence of acid are immediately converted to ammonium salts). One of the two oxygen groups on the carboxylic acid are derived from a water molecule and the amine (or ammonia) gains the hydrogen ion.
The imidium chloride salts is thermodynamically unstable, and low temperatures help prevent elimination to an amide and alkyl chloride. [8] It should be appreciated that the Pinner reaction refers specifically to an acid catalyzed process, but that similar results can often be achieved using base catalysis.
An amidate/imidate anion is formed upon deprotonation of an amide or imidic acid.Since amides and imidic acids are tautomers, they form the same anion upon deprotonation.The two names are thus synonyms describing the same anion, although arguably, imidate refers to the resonance contributor on the left, while amidate refers to the resonance contributor on the right.
Amides do not readily participate in nucleophilic substitution reactions. Amides are stable to water, and are roughly 100 times more stable towards hydrolysis than esters. [citation needed] Amides can, however, be hydrolyzed to carboxylic acids in the presence of acid or base.
An excess of the base is employed to account for impurities that consume base and reaction of the base with the ether solvent. Care should be taken when HMPA is added to lithium amide reactions, as it is a known animal carcinogen. Organolithium reagents may also be used; however, lower temperatures are required to avoid decomposition of the ...
These reactions proceed via the intermediacy of amides. The intramolecular reaction of a carboxylic acid with an amide is far faster than the intermolecular reaction, which is rarely observed. They may also be produced via the oxidation of amides, particularly when starting from lactams. [6] R(CO)NHCH 2 R' + 2 [O] → R(CO)N(CO)R' + H 2 O
In enzymology, an amidase (EC 3.5.1.4, acylamidase, acylase (misleading), amidohydrolase (ambiguous), deaminase (ambiguous), fatty acylamidase, N-acetylaminohydrolase (ambiguous)) is an enzyme that catalyzes the hydrolysis of an amide. In this way, the two substrates of this enzyme are an amide and H 2 O, whereas its two products are ...
Common reaction conditions include use of sodium or potassium alkoxide as base in hexane or tetrahydrofuran solvents, at temperatures ranging between 200–400 °C. A hydrolysis step is also required in the synthesis. The Madelung synthesis is important because it is one of few known reactions that produce indoles from a base-catalyzed thermal ...