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Lactam
A lactam is a Cyclic compound, cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words ''lactone'' + ''amide''. Nomenclature Greek_alphabet#Letters, Greek prefixes in alphabetical order indicate ring size. This ring-size nomenclature stems from the fact that hydrolysis of an α-lactam gives an α-amino acid and that of a β-Lactam gives a β-amino acid, and so on. Synthesis General synthetic methods are used for the organic synthesis of lactams. Beckmann rearrangement Lactams form by the Acid catalysis, acid-catalyzed Rearrangement reaction, rearrangement of oximes in the Beckmann rearrangement. Schmidt reaction Lactams form from cyclic ketones and hydrazoic acid in the Schmidt reaction. Cyclohexanone with hydrazoic acid, forms Caprolactam, ε - Caprolactum, which upon treatment with excess acid forms Pentylenetetrazol, Cardiazole, a heart stimulant. Cyclization of amino acids Lactams can be formed fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ε-Lactam
Caprolactam (CPL) is an organic compound with the formula (CH2)5C(O)NH. This colourless solid is a lactam (a cyclic amide) of caproic acid. Global demand for this compound is approximately five million tons per year, and the vast majority is used to make Nylon 6 filament, fiber, and plastics. Synthesis and production Caprolactam was first described in the late 1800s when it was prepared by the cyclization of ε-aminocaproic acid, the product of the hydrolysis of caprolactam. World demand for caprolactam was estimated to reach five million tons per year for 2015. 90% of caprolactam produced is used to make filament and fiber, 10% for plastics, and a small amount is used as a chemical intermediate. Due to its commercial significance, many methods have been developed for the production of caprolactam. It was estimated that 90% of all caprolactam is synthesised from cyclohexanone (1), which is first converted to its oxime (2). Treatment of this oxime with acid induces the Beckmann rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactams
A lactam is a cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words '' lactone'' + ''amide''. Nomenclature Greek prefixes in alphabetical order indicate ring size. This ring-size nomenclature stems from the fact that hydrolysis of an α-lactam gives an α-amino acid and that of a β-Lactam gives a β-amino acid, and so on. Synthesis General synthetic methods are used for the organic synthesis of lactams. Beckmann rearrangement Lactams form by the acid-catalyzed rearrangement of oximes in the Beckmann rearrangement. Schmidt reaction Lactams form from cyclic ketones and hydrazoic acid in the Schmidt reaction. Cyclohexanone with hydrazoic acid, forms ε - Caprolactum, which upon treatment with excess acid forms Cardiazole, a heart stimulant. Cyclization of amino acids Lactams can be formed from cyclisation of amino acids via the coupling between an amine and a carboxylic acid within the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckmann Rearrangement
The Beckmann rearrangement, named after the German chemist Ernst Otto Beckmann (1853–1923), is a rearrangement reaction, rearrangement of an oxime functional group to substituted amides. The rearrangement has also been successfully performed on haloimines and nitrones. Cyclic oximes and haloimines yield lactams. The Beckmann rearrangement is often catalyzed by acid; however, other reagents have been known to promote the rearrangement. These include tosyl chloride, thionyl chloride, phosphorus pentachloride, phosphorus pentoxide, triethylamine, sodium hydroxide, trimethylsilyl iodide among others. The Beckmann fragmentation is another reaction that often competes with the rearrangement, though careful selection of promoting reagent and solvent conditions can favor the formation of one over the other, sometimes giving almost exclusively one product. The rearrangement occurs Stereospecificity, stereospecifically for ketoximes and N-chloro/N-fluoro imines, with the migrating group be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
γ-Lactam
2-Pyrrolidone, also known as 2-pyrrolidinone or butyrolactam, is an organic compound consisting of a 5-membered lactam, making it the simplest γ-lactam. It is a colorless liquid that is miscible with water and most common organic solvents. 2-Pyrrolidone itself and it various derivatives, especially N-methylpyrrolidone, have a variety of industrial uses. Production 2-Pyrrolidone is produced industrially almost exclusively by treating aqueous gamma-butyrolactone with ammonia at a temperature of 250–290 °C and pressures ranging from 0.4–1.4 MPa over solid magnesium silicate catalysts. : The reaction is carried out in a tubular reactor which is packed with the solid catalyst. The latter is arranged as a fixed bed and the reaction is carried out in the vapor phase. Product yields of 75–85% are reached. After subsequent distillation and purification, the desired 2-pyrrolidone is obtained with a purity of 99.5%. Alternative routes include the catalytic or electrochemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
δ-Lactam
2-Piperidinone (2-piperidone or δ-valerolactam) is an organic compound with the formula . Valerolactam is formed by dehydrogenation of 5-amino-1-pentanol, catalyzed by rhodium and ruthenium complexes, The compound, a colorless solid, is classified as a lactam. It is the monomer of nylon 5, a polyamide A polyamide is a polymer with repeating units linked by amide bonds. Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made throug ...: : References {{heterocyclic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oximes
In organic chemistry, an oxime is an organic compound belonging to the imines, with the general formula , where R is an organic side-chain and R' may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substituted oximes form a closely related family of compounds. Amidoximes are oximes of amides () with general structure . Oximes are usually generated by the reaction of hydroxylamine with aldehydes () or ketones (). The term ''oxime'' dates back to the 19th century, a combination of the words ''oxygen'' and ''imine''. Structure and properties If the two side-chains on the central carbon are different from each other—either an aldoxime, or a ketoxime with two different "R" groups—the oxime can often have two different geometric stereoisomeric forms according to the ''E''/''Z'' configuration. An older terminology of ''syn'' and ''anti'' was used to identify especially aldoximes according to whether the R group was closer or further from the hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Compound
A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon (i.e., are carbocycles), none of the atoms are carbon (inorganic cyclic compounds), or where both carbon and non-carbon atoms are present ( heterocyclic compounds with rings containing both carbon and non-carbon). Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclization
A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon (i.e., are carbocycles), none of the atoms are carbon (inorganic cyclic compounds), or where both carbon and non-carbon atoms are present (heterocyclic compounds with rings containing both carbon and non-carbon). Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amide
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula , where R, R', and R″ represent any group, typically organyl functional group, groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the Polymer backbone, main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a Derivative (chemistry), derivative of a carboxylic acid () with the hydroxyl group () replaced by an amino group (); or, equivalently, an acyl group, acyl (alkanoyl) group () joined to an amino group. Common amides are formamide (), acetamide (), benzamide (), and dimethylformamide (). Some uncommon examples of amides are ''N''-chloroacetamide () and chloroformamide (). Amides are qualified as primary (chemistry), primary, secondary (chemistry), secondary, and tertiary (chemistry), tertiary according to the number of acyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Catalysis
In acid catalysis and base catalysis, a chemical reaction is catalyzed by an acid or a base. By Brønsted–Lowry acid–base theory, the acid is the proton (hydrogen ion, H+) donor and the base is the proton acceptor. Typical reactions catalyzed by proton transfer are esterifications and aldol reactions. In these reactions, the conjugate acid of the carbonyl group is a better electrophile than the neutral carbonyl group itself. Depending on the chemical species that act as the acid or base, catalytic mechanisms can be classified as either specific catalysis and general catalysis. Many enzymes operate by general catalysis. Applications and examples Brønsted acids Acid catalysis is mainly used for organic chemical reactions. Many acids can function as sources for the protons. Acid used for acid catalysis include hydrofluoric acid (in the alkylation process), phosphoric acid, toluenesulfonic acid, polystyrene sulfonate, heteropoly acids, zeolites. Strong acids catalyze the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Ketones
In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' are methyl), with the formula . Many ketones are of great importance in biology and industry. Examples include many sugars (ketoses), many steroids, ''e.g.'', testosterone, and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considered retained IUPAC names, although some introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
