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Benzocyclobutene
Benzocyclobutene (BCB) is a benzene ring fused to a cyclobutane ring. It has chemical formula . BCB is frequently used to create photosensitive polymers. BCB-based polymer dielectrics may be spun on or applied to various Wafer (electronics), substrates for use in Micro Electro-Mechanical Systems (MEMS) and microelectronics processing. Applications include wafer bonding, optical interconnects, low-κ dielectrics, or even intracortical neural implants. Reactions Benzocyclobutene is a strained system which, upon heating to approximately 180 °C, causes the cyclobutene to undergo a conrotatory Cyclic_compound#Ring-opening_reactions, ring-opening reaction, forming o-xylylene, ''o''-xylylene. Since this process destroys the aromaticity of the benzene ring, the reverse reaction is highly favored. ''o''-Xylylenes generated in this way have been used prolifically in cycloaddition reactions, which restore the aromaticity to the benzene ring, while forming a new annulation, annulated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S33005
S33005 is a serotonin–norepinephrine reuptake inhibitor (SNRI) that was under development by Servier for the treatment of depression and related disorders. It is structurally related to venlafaxine but has a more complex molecular structure. Venlafaxine appears to be a sigma modulator, but it is not known if S33005 shares this activity. Synthesis "The 1-cyano-benzocyclobutenes used as starting material are obtained, for example, by subjecting a β- rthohalogeno-phenylpropionitrile to intramolecular condensation in the presence of potassium amide, or by brominating a benzocyclobutene in position 1 with ''N''-bromosuccinimide, followed by exchange of the bromine atom for a cyano group by means of sodium cyanide." See also * Milnacipran References External links PubMed searchBinding Database* The patent and synthesis discussion can be found in {{Navboxes , title = Pharmacodynamics Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-xylylene
In organic chemistry, a xylylene (sometimes quinone-dimethide) is any of the constitutional isomers having the formula C6H4(CH2)2. These compounds are related to the corresponding quinones and quinone methides by replacement of the oxygen atoms by CH2 groups. ''ortho''- and ''para''-xylylene are best known, although neither is stable in solid or liquid form. The ''meta'' form is a diradical. Certain substituted derivatives of xylylenes are however highly stable, such as tetracyanoquinodimethane and the xylylene dichlorides. p-Xylylene ''p''-Xylylene forms upon pyrolysis of ''p''-xylene or, more readily, the α-substituted derivatives. ''p''-Xylylene dimerizes with moderate efficiency to give ''p''-cyclophane: Further heating of the ''p''-cyclophane gives poly(''para''-xylylene). o-Xylylenes o-Xylylenes (''o''-quinodimethanes) are often generated in situ, e.g., by the pyrolysis of the corresponding sulfone. Another method involves 1,4-elimination of ortho benzylic silanes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzocyclobutadiene
Benzocyclobutadiene is the simplest polycyclic hydrocarbon, being composed of an aromatic benzene ring fused to an anti-aromatic cyclobutadiene ring. It has chemical formula . Though the benzene ring is stabilized by aromaticity, the cyclobutadiene portion has a destabilizing effect. This results into it being a non-aromatic compound - neither behaving as aromatic nor an antiaromatic one. For this reason, benzocyclobutadiene will readily dimerize or polymerize and it reacts as a dienophile in Diels-Alder reactions. Benzocyclobutadiene is used in the production of the pharmaceutical drug naflocort. See also *Pentalene Pentalene is a polycyclic hydrocarbon composed of two fused cyclopentadiene rings. It has chemical formula . It is antiaromatic, because it has 4''n'' π electrons where ''n'' is any integer. For this reason it dimerizes even at temperatures as ... References {{reflist Polycyclic aromatic hydrocarbons Bicyclic compounds Four-membered rings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-κ Dielectric
In semiconductor manufacturing, a low-κ is a material with a small relative dielectric constant (κ, kappa) relative to silicon dioxide. Low-κ dielectric material implementation is one of several strategies used to allow continued scaling of microelectronic devices, colloquially referred to as extending Moore's law. In digital circuits, insulating dielectrics separate the conducting parts (wire interconnects and transistors) from one another. As components have scaled and transistors have gotten closer together, the insulating dielectrics have thinned to the point where charge build up and crosstalk adversely affect the performance of the device. Replacing the silicon dioxide with a low-κ dielectric of the same thickness reduces parasitic capacitance, enabling faster switching speeds (in case of synchronous circuits) and lower heat dissipation. In conversation such materials may be referred to as "low-k" (spoken "low-kay") rather than "low-κ" (low-kappa). Low-κ materials In in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromaticity
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturated compounds having single bonds, and other geometric or connective non-cyclic arrangements with the same set of atoms. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, but only aromatic rings have enhanced stability. The term ''aromaticity'' with this meaning is historically related to the concept of having an aroma, but is a distinct property from that meaning. Since the most common aromatic compounds are derivatives of benzene (an aromatic hydrocarbon common in petroleum and its distillates), the word ''aromatic'' occasionally refers informally to benzene derivatives, and so it was first defined. Nevertheless, many non-be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphetamine
Amphetamine (contracted from alpha- methylphenethylamine) is a strong central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. It is also commonly used as a recreational drug. Amphetamine was discovered in 1887 and exists as two enantiomers: levoamphetamine and dextroamphetamine. ''Amphetamine'' properly refers to a specific chemical, the racemic free base, which is equal parts of the two enantiomers in their pure amine forms. The term is frequently used informally to refer to any combination of the enantiomers, or to either of them alone. Historically, it has been used to treat nasal congestion and depression. Amphetamine is also used as an athletic performance enhancer and cognitive enhancer, and recreationally as an aphrodisiac and euphoriant. It is a prescription drug in many countries, and unauthorized possession and distribution of amphetamine are often tightly controlled due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2C-B
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) is a psychedelic drug of the 2C family. It was first synthesized by Alexander Shulgin in 1974. In Shulgin's book '' PiHKAL'', the dosage range is listed as 12–24 mg. As a recreational drug, 2C-B is sold as a white powder sometimes pressed in tablets or gel caps. It is also referred to by a number of street names. The drug is usually taken orally, but can also be insufflated or vaporized. While being primarily a psychedelic it is also a mild entactogen. History 2C-B was synthesized from 2,5-dimethoxybenzaldehyde by Alexander Shulgin in 1974. It first saw use among the psychiatric community as an aid during therapy. 2C-B was first sold commercially as a purported aphrodisiac under the trade name "Erox", which was manufactured by the German pharmaceutical company Drittewelle. For several years, it was available as tablets in Dutch smart shops under the name "Nexus" and "B-Dub". Patterns of use 2C-B first became popularized in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Analog
A structural analog (analogue in modern traditional English; Commonwealth English), also known as a chemical analog or simply an analog, is a compound having a structure similar to that of another compound, but differing from it in respect to a certain component. It can differ in one or more atoms, functional groups, or substructures, which are replaced with other atoms, groups, or substructures. A structural analog can be imagined to be formed, at least theoretically, from the other compound. Structural analogs are often isoelectronic. Despite a high chemical similarity, structural analogs are not necessarily functional analogs and can have very different physical, chemical, biochemical, or pharmacological properties. In drug discovery, either a large series of structural analogs of an initial lead compound are created and tested as part of a structure–activity relationship study or a database is screened for structural analogs of a lead compound. Chemical analogues of il ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivabradine
Ivabradine, sold under the brand name Procoralan among others, is a medication, which is a funny current (I''f'') inhibitor, used for the symptomatic management of heart-related chest pain and heart failure. Patients who qualify for use of Ivabradine for coronary heart failure are patients who have symptomatic heart failure, with reduced ejection volume, and heart rate at least 70 bpm, and the condition not able to be fully managed by beta blockers. Ivabradine acts by allowing negative chronotropy in the sinoatrial structure thus reducing the heart rate via specific inhibition of the pacemaker current, a mechanism different from that of beta blockers and calcium channel blockers, two commonly prescribed antianginal classes of cardiac pharmaceuticals. Ivabradine has no apparent inotropic properties and may be a cardiotonic agent. Medical uses It is used for the symptomatic treatment of chronic stable angina pectoris in patients with normal sinus rhythm who cannot take beta blocke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulation
In organic chemistry annulation (from the Latin ''anellus'' for "little ring"; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule. : Examples are the Robinson annulation, Danheiser annulation and certain cycloadditions. Annular molecules are constructed from side-on condensed cyclic segments, for example helicenes and acenes. In transannulation a bicyclic molecule is created by intramolecular carbon-carbon bond formation in a large monocyclic ring. An example is the samarium(II) iodide induced ketone - alkene cyclization of ''5-methylenecyclooctanone'' which proceeds through a ketyl intermediate: : Benzannulation The term benzannulated compounds refers to derivatives of cyclic compounds (usually aromatic) which are fused to a benzene ring. Examples are listed in the table below: In contemporary chemical literature, the term benzannulation also means "construction of benzene rings from acyclic precursors". upright=1.4, Protonatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloaddition Reaction
In organic chemistry, a cycloaddition is a chemical reaction in which "two or more unsaturated molecules (or parts of the same molecule) combine with the formation of a cyclic adduct in which there is a net reduction of the bond multiplicity". The resulting reaction is a cyclization reaction. Many but not all cycloadditions are concerted and thus pericyclic. Nonconcerted cycloadditions are not pericyclic. As a class of addition reaction, cycloadditions permit carbon–carbon bond formation without the use of a nucleophile or electrophile. Cycloadditions can be described using two systems of notation. An older but still common notation is based on the size of linear arrangements of atoms in the reactants. It uses parentheses: where the variables are the numbers of linear atoms in each reactant. The product is a cycle of size . In this system, the standard Diels-Alder reaction is a (4 + 2)-cycloaddition, the 1,3-dipolar cycloaddition is a (3 + 2)-cycloadditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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