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The amide derivatives that are obtained by Beckmann rearrangement can be transformed into a carboxylic acid by means of hydrolysis ( base or acid catalyzed ). And an amine by hoffman degradation of the amide in the presence of alkali hypoclorites at 80 degrees Celsius, the degradation is itself prone to side reactions namely, the formation of biurets or, cyanate polymers, To avoid this side reaction strict temperature control is necessary, the reaction must be conducted at sufficient temperature to isomerise the cyanate to the isocyante.
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amide and derivatives
Generally oximes can be changed to the corresponding amide derivatives by treatment with various acids.
amide and are
; it is indeed the strongest Arrhenius base, but a number of compounds that cannot exist in aqueous solution, such as n-butyllithium and sodium amide, are more basic.
Polymers containing amide or carbonyl groups can form hydrogen bonds between adjacent chains ; the partially positively charged hydrogen atoms in N-H groups of one chain are strongly attracted to the partially negatively charged oxygen atoms in C = O groups on another.
Isocyanates are intermediates in the Hofmann rearrangement, in which a primary amide is treated with sodium hypobromite to form an isocyanate intermediate.
It may be of interest to note that the protein CD spectra used in secondary structure estimation are related to the π to π * orbital absorptions of the amide bonds linking the amino acids.
Consistent with this rule, strong bases such as alkoxide ( RO < sup >−</ sup >), hydroxide ( HO < sup >−</ sup >), and amide ( R < sub > 2 </ sub > N < sup >−</ sup >) are poor leaving groups.
A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85 % of the amide linkages, (- CO-NH -) are attached directly to two aromatic rings.
Ergine ( LSA ), isoergine ,-lysergic acid N -( α-hydroxyethyl ) amide and lysergol have been isolated from I. tricolor, I. violacea and / or purple morning glory ( I. purpurea ); although these are often assumed to be the cause of the plants ' effects, this is not supported by scientific studies, which show although they are psychoactive, they are not notably hallucinogenic.
The hallucinogenic properties of the seeds are usually attributed to ergine ( also known as d-lysergic acid amide, or LSA ), although the validity of the attribution remains disputed.
Because the amide is a regular activating group the products formed are the para and ortho isomers.
The chemical reactions of NHS-and sulfo-NHS esters are essentially identical, in that they both react spontaneously with amines to form an amide bond.
In all, rifA-E assemble a linear undecaketide and are followed by rifF, which encodes an amide synthase and causes the undecaketide to release and form a macrolactam structure.
The protein chains are held together by intermolecular hydrogen bonding, that is hydrogen bonding between amide groups of two separate chains.
In proteins ( composed of amino acids ) the side chains are attached to the alpha-carbon atoms of the amide backbone.
In organic chemistry, peptide synthesis is the production of peptides, which are organic compounds in which multiple amino acids are linked via amide bonds which are also known as peptide bonds.
Similar to the Boc strategy, two primary resins are used, based on whether a C-terminal carboxylic acid or amide is desired.
Structures are alternately bound via amide and ester bridges.
The crystals formed during drawing are held together by hydrogen bonds between the amide hydrogens of one chain and the carbonyl oxygens of another chain.
This is remarkable because in other period 2 elements lithium salts are common e. g. lithium fluoride, lithium hydroxide lithium amide and methyllithium.
Nitrile hydratases are almost invariably co-expressed with an amidase, which converts the amide to the carboxylic acid, consequently it can sometimes be difficult to distinguish nitrilase activity from nitrile hydratase plus amidase activity.
amide and obtained
Glutethimide ( 2-ethyl-2-phenylgutarimide ) is synthesized by addition of 2-phenylbutyronitrile to the methylacrylate ( Michael reaction ), and the subsequent alkaline hydrolysis of the nitrile group in the obtained compound into an amide group, and the subsequent acidic cyclization of the product into the desired glutethimide.
amide and by
This trend is due to the amide character of the β-lactam being reduced by the aplanarity of the system.
A novel method is by reaction of certain amides with carbonitriles under electrophilic activation of the amide with 2-chloro-pyridine and trifluoromethanesulfonic anhydride:
A peptide bond can only be broken by amide hydrolysis ( the adding of water ).
) Similarly, a strongly electronegative substituent ( such as fluorine ) near the amide nitrogen favors the single-bonded form, by competing with the amide oxygen to " steal " an electron from the amide nitrogen ( See Figure 4.
This intermediate tends to revert to the amide form, expelling the attacking group, since the amide form is usually favored by free energy, ( presumably due to the strong resonance stabilization of the peptide group ).
For completeness, the proposal that proteins contained amide linkages was made as early as 1882 by the French chemist E. Grimaux.
A second hypothesis, the cyclol hypothesis advanced by Dorothy Wrinch, proposed that the linear polypeptide underwent a chemical cyclol rearrangement C = O + HN C ( OH )- N that crosslinked its backbone amide groups, forming a two-dimensional fabric.
In proteins, the secondary structure is defined by the patterns of hydrogen bonds between backbone amide and carboxyl groups.
In addition, trypsin contains an " oxyanion hole " formed by the backbone amide hydrogen atoms of Gly-193 and Ser-195, which serves to stabilize the developing negative charge on the carbonyl oxygen atom of the cleaved amides.
As far as laboratory synthesis is concerned, in 1882, Horbaczewski claimed to have prepared uric acid by melting urea hydrogen peroxide with glycine, trichlorolactic acid, and its amide.
Other forms of vitamin B < sub > 3 </ sub > include the corresponding amide, nicotinamide (" niacinamide "), where the carboxyl group has been replaced by a carboxamide group (), as well as more complex amides and a variety of esters.
Its side-chain is an amide formed by replacing the side-chain hydroxyl of glutamic acid with an amine functional group making it the amide of glutamic acid.
Pepsin will digest up to 20 % of ingested amide bonds by cleaving preferentially after the N-terminal of aromatic amino acids such as phenylalanine, tryptophan, and tyrosine.
Mercury is known to interfere with metabolism and function by combining with phosphoryl, carboxyl, amide and amine groups resulting in enzyme inhibition and protein precipitation.
Sodium azide is made industrially by the reaction of nitrous oxide, N < sub > 2 </ sub > O with sodium amide, NaNH < sub > 2 </ sub >, in liquid ammonia as solvent.
amide and Beckmann
The Beckmann rearrangement, named after the German chemist Ernst Otto Beckmann ( 1853 – 1923 ), is an acid-catalyzed rearrangement of an oxime to an amide.
In the presence of sulfuric acid catalyst, the oxime undergoes the Beckmann rearrangement to give the cyclic amide caprolactam:
amide and rearrangement
* Hofmann rearrangement, the organic reaction of a primary amide to a primary amine with one fewer carbon atom
The Hofmann rearrangement is the organic reaction of a primary amide to a primary amine with one fewer carbon atom.
amide and can
A new study has suggested that β-lactams can undergo ring-openening polymerization to form amide bonds, to become nylon-3 polymers.
Sugar moieties can be attached to the sidechain hydroxyl groups of Ser / Thr or to the sidechain amide groups of Asn.
When proline is bound as an amide in a peptide bond, its nitrogen is not bound to any hydrogen, meaning it cannot act as a hydrogen bond donor, but can be a hydrogen bond acceptor.
* In N-glycosylation ( see on the right ), the addition of sugar chains can happen at the amide nitrogen on the side-chain of the asparagine.
This relatively simple process uses only one amide solvent and therefore spinning can be done directly after the polymer production.
The second type of transamination reaction, which can be described as a nucleophilic substitution of one amine or amide anion on an amine or ammonium salt.
For example, the attack of a primary amine by a primary amide anion can be used to prepare secondary amines:
For example, while fatty acid amide hydrolase ( FAAH ) can hydrolyze the endocannabinoids 2-arachidonoylglycerol ( 2-AG ) and anandamide at comparable rates in vitro, genetic or pharmacological disruption of FAAH elevates anandamide but not 2-AG, suggesting that 2-AG is not an endogenous, in vivo substrate for FAAH.
Local anesthetics can be either ester or amide based.
Furthermore, the product can be easily converted into the corresponding Weinreb amide, without any loss of selectivity, allowing for the facile introduction of the C14 methyl group.
A nitrene can easily insert into a carbon to hydrogen covalent bond yielding an amine or amide.
An asparagine substitution for His-48 maintains wild-type activity, as the amide functional group on asparagine can also function to lower the pKa, or acid dissociation constant, of the bridging water molecule.
The O-acylisourea 2 can react with an additional carboxylic acid 1 to give an acid anhydride 5, which can react further to give the desired amide 3.
When the methyl groups are replaced by pyridine amide groups a host-guest chemistry interaction can take place between the Tröger's base and an aliphatic dicarboxylic acid ..
Organic compounds of the amide group can react in many different organic processes to form other useful compounds for synthesis.
Paired with the pyrolysis and nucleophilic trapping reaction, above, the alkylated products can be carried on to produce a range of different amide and ester compounds.
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