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Benzoxazines
Benzoxazines are a group of isomeric bicyclic heterocyclic chemical compounds that consist of a benzene ring fused to an oxazine ring. The different isomers depend on the relative positions of the oxygen and nitrogen atoms in the oxazine ring, on the location of ring fusion, and on the position of the double bond in the oxazine ring. They have the molecular formula C8H7NO. Preparation 1,3-Benzoxazines can be synthesized by the Mannich reaction using a phenol, an amine, and formaldehyde. Uses Pharmaceutical drugs Benzoxazine rings form the central chemical structure of a number of pharmaceutical drugs including, for example, apararenone, elbasvir, and etifoxine. Polymers Polybenzoxazines, also called benzoxazine resins, are a class of polymers that are produced from the ring-opening polymerization of 3-phenyl-2,4-dihydro-1,3-benzoxazine monomers and its chemical derivatives The derivative of a function is the rate of change of the function's output relative to its input va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybenzoxazine
Polybenzoxazines, also called benzoxazine resins, are cured polymerization products derived from benzoxazine monomers. Monomers Benzoxazines are bicyclic heterocyclic compounds containing one oxygen and one nitrogen atom in a doubly unsaturated six-member ring, specifically a 1,3-oxazine ring, fused with a benzene ring. The systematic IUPAC name of the prototypical unsubstituted monomer is 3,4-dihydro-3-phenyl-2''H''-1,3-benzoxazine. Benzoxazines are products of condensation between an amine, a phenol and formaldehyde, used to produce thermoset resins or thermosetting polymer. Because of the wide availability and low-cost of starting materials (amines, phenols and formaldehyde), as well as ease of preparation ( one-pot reaction) diverse benzoxazines are available. Numerous research focus on the different curing temperature, and polymer properties, such as cross-linking, from benzoxazines derived from substituted phenols. Commercial benzoxazines by Huntsman are based on bisphenol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzoxazine Examples
Benzoxazines are a group of isomeric bicyclic heterocyclic chemical compounds that consist of a benzene ring fused to an oxazine ring. The different isomers depend on the relative positions of the oxygen and nitrogen atoms in the oxazine ring, on the location of ring fusion, and on the position of the double bond in the oxazine ring. They have the molecular formula C8H7NO. Preparation 1,3-Benzoxazines can be synthesized by the Mannich reaction using a phenol, an amine, and formaldehyde. Uses Pharmaceutical drugs Benzoxazine rings form the central chemical structure of a number of pharmaceutical drugs including, for example, apararenone, elbasvir, and etifoxine. Polymers Polybenzoxazines, also called benzoxazine resins, are a class of polymers that are produced from the ring-opening polymerization of 3-phenyl-2,4-dihydro-1,3-benzoxazine monomers and its chemical derivatives The derivative of a function is the rate of change of the function's output relative to its input val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxazine
Oxazines are heterocyclic compounds containing one oxygen and one nitrogen atom in a doubly unsaturated six-membered ring. Isomers exist depending on the relative position of the heteroatoms and relative position of the double bonds. By extension, the derivatives are also referred to as oxazines; examples include ifosfamide and morpholine (tetrahydro-1,4-oxazine). A commercially available dihydro-1,3-oxazine is a reagent in the Meyers synthesis of aldehydes. Fluorescent dyes such as Nile red and Nile blue are based on the aromatic benzophenoxazine. Cinnabarine and cinnabaric acid are two naturally occurring dioxazines, being derived from biodegradation of tryptophan. Dioxazines Dioxazines are pentacyclic compounds consisting of two oxazine subunits. A commercially important example is the pigment pigment violet 23. Benzoxazines Benzoxazines are bicyclic compounds formed by the ring fusion of a benzene ring with an oxazine. Polybenzoxazines are a class of polymers formed b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apararenone
Apararenone (INN) (developmental code name MT-3995) is a nonsteroidal antimineralocorticoid which is under development by Mitsubishi Tanabe Pharma for the treatment of diabetic nephropathies and non-alcoholic steatohepatitis. It was also previously being developed for the treatment of hypertension, but development was discontinued for this indication. Apararenone acts as a highly selective antagonist of the mineralocorticoid receptor (Ki < 50 nM), the receptor for . As of 2017, it is in phase II |
Etifoxine
Etifoxine ( INN; also known as etafenoxine; trade name Stresam) is an anxiolytic and anticonvulsant drug developed by Hoechst in the 1960s. It is sold in approximately 40 countries for anxiety disorders, without the sedation and ataxia associated with benzodiazepine drugs. It has similar anxiolytic effects to benzodiazepine drugs, but is structurally distinct, although it has structural elements in common with them. Studies suggest is as effective as lorazepam as an anxiolytic, but has fewer side effects. Etifoxine is not approved by the U.S. Food and Drug Administration. The European Medicines Agency (EMA) started a review procedure regarding the effectiveness and safety of etifoxine following a French study that compares etifoxine's effectiveness to placebo and lorazepam. In January 2022, the EMA "finalized its review of Stresam and concluded that the medicine can continue to be used for the treatment of anxiety disorders, but it must not be used in patients who previously h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which '' bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma-Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore Corporation, Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannich Reaction
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). The final product is a β-amino-carbonyl compound also known as a Mannich 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. center, 500px, 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 Mannich reaction starts with the nucleophilic addition of an amine to a carbonyl group followed by dehydration to the Schiff base. The Schiff base is an electrophile which reacts in a second step in an electrophilic addition with an enol formed from a carbonyl compound containing an acidic alpha-proton. The Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elbasvir
Elbasvir is a drug approved by the FDA in January 2016 for the treatment of hepatitis C. It was developed by Merck and completed Phase III trials, used in combination with the NS3/ 4A protease inhibitor grazoprevir under the trade name '' Zepatier'', either with or without ribavirin. Elbasvir is a highly potent and selective NS5A inhibitor of the hepatitis C virus NS5A replication complex. It has only been investigated as a combination product with other complementary hepatitis C antiviral drugs such as grazoprevir and MK-3682, and it is unclear whether elbasvir would show robust antiviral activity if it was administered by itself. Nevertheless, combination products of this type represent the most successful approach yet developed for actually curing hepatitis C, rather than merely slowing the progression of the disease. Side effects Side effects have only been assessed in the combination with grazoprevir; see Elbasvir/grazoprevir#Side effects. Interactions Elbasvir is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by a chemical reaction. In the past, derivative also meant a compound that ''can be imagined to'' arise from another compound, if one atom or group of atoms is replaced with another atom or group of atoms, but modern chemical language now uses the term structural analog for this meaning, thus eliminating ambiguity. The term "structural analogue" is common in organic chemistry. In biochemistry, the word is used for compounds that at least theoretically can be formed from the precursor compound. Chemical derivatives may be used to facilitate analysis. For example, melting point (MP) analysis can assist in identification of many organic compounds. A crystalline derivative may be prepared, such as a semicarbazone or 2,4-dinitrophenylhydrazone (derived from aldehydes or ketones), as a simple way of verifying the identity of the original compound, assuming that a table of derivative MP values is avai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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