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3-bromopropene
Allyl bromide (3-bromopropene) is an organic halide. It is an alkylating agent used in synthesis of polymers, pharmaceuticals, perfumes and other organic compounds. Allyl bromide is a colorless liquid, although commercial samples appear yellow or brown. It is an irritant and a potentially dangerous alkylating agent. Allyl bromide is more reactive but more expensive than allyl chloride, and these considerations guide its use. Preparation Hydrohalogenation Allyl bromide is produced commercially from allyl alcohol and hydrobromic acid: :CH2=CHCH2OH + HBr → CH2=CHCH2Br + H2O It can also be prepared by the halogen-exchange reaction between allyl chloride and hydrobromic acid or by the allylic bromination of propene. Reactions and uses Allyl bromide is an electrophilic alkylating agent. It reacts with nucleophiles, such as amines, carbanions, alkoxides, etc., to introduce the allyl group: :CH2=CHCH2Br + Nu− → CH2=CHCH2Nu + Br− (Nu− is a nucleophile) It is used in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centipoise
The poise (symbol P; ) is the unit of dynamic viscosity (absolute viscosity) in the centimetre–gram–second system of units (CGS). It is named after Jean Léonard Marie Poiseuille (see Hagen–Poiseuille equation). The centipoise (1 cP = 0.01 P) is more commonly used than the poise itself. Dynamic viscosity has dimensions of \mathrm, that is, mathsf^1 \mathsf^ \mathsf^/math>. 1~\text = 0.1~\text^ \text \text^ = 1~\text^ \text \text^ = 1~\text \text \text^. The analogous unit in the International System of Units is the pascal-second (Pa⋅s): 1~\text \text = 1~\text \text \text^ = 1~\text^ \text \text^ = 10~\text. The poise is often used with the metric prefix ''centi-'' because the viscosity of water at 20 °C (standard conditions for temperature and pressure) is almost exactly 1 centipoise. A centipoise is one hundredth of a poise, or one millipascal-second (mPa⋅s) in SI units (1 cP = 10−3 Pa⋅s = 1 mPa⋅s). The CGS symbol f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of electrons. Amines can also exist as hetero cyclic compounds. Aniline is the simplest aromatic amine, consisting of a benzene ring bonded to an amino group. Amines are classified into three types: primary (1°), secondary (2°), and tertiary (3°) amines. Primary amines (1°) contain one alkyl or aryl substituent and have the general formula RNH2. Secondary amines (2°) have two alkyl or aryl groups attached to the nitrogen atom, with the general formula R2NH. Tertiary amines (3°) contain three substituent groups bonded to the nitrogen atom, and are represented by the formula R3N. The functional group present in primary amines is called the amino group. Classification of amines Amines can be classified according to the nature and number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allylmagnesium Bromide
Allylmagnesium bromide is a Grignard reagent used for introducing the allyl group. It is commonly available as a solution in diethyl ether. It may be synthesized by treatment of magnesium with allyl bromide while maintaining the reaction temperature below 0 °C to suppress formation of hexadiene. Allyl chloride can also be used in place of the bromide to give allylmagnesium chloride. These reagents are used to prepare transition-metal allyl complex, metal allyl complexes. References Further reading * {{cite book , author = Chabot, P. , editor1=Rakita, P. E. , editor2=Silverman, G. , chapter = 7. Infrared and Raman Spectroscopy , title = Handbook of Grignard Reagents , year = 1996 , pages = 93–102 , location = New York, N.Y. , publisher = Marcel Dekker , isbn = 0-8247-9545-8 Organomagnesium compounds Allyl compounds Bromides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs to the ether class of organic compounds. It is a common solvent and was formerly used as a general anesthetic. Production Most diethyl ether is produced as a byproduct of the vapor-phase Hydration reaction, hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid Catalysis, catalysts and can be adjusted to make more ether if the need arises: Vapor-phase Dehydration reaction, dehydration of ethanol over some Aluminium oxide, alumina catalysts can give diethyl ether yields of up to 95%. : Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Uses The dominant use of diethyl ether is as a solvent. One particular application is in the production of cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium
Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table), it occurs naturally only in combination with other elements and almost always has an oxidation state of +2. It reacts readily with air to form a thin Passivation (chemistry), passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium Salt (chemistry), salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight magnesium alloy, alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three Helium nucleus, helium nuclei to a carbon nucleus. When such stars explo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiamylal
Thiamylal (Surital) is a barbiturate derivative invented in the 1950s. It has sedative, anticonvulsant, and hypnotic effects, and is used as a strong but short acting sedative. Thiamylal is still in current use, primarily for induction in surgical anaesthesia or as an anticonvulsant to counteract side effects from other anaesthetics. It is the thiobarbiturate analogue of secobarbital Secobarbital, sold under the brand name Seconal among others, is a short-acting barbiturate drug originally used for the treatment of insomnia. It was patented by Eli Lilly and Company in 1934 in the United States. It possesses anesthetic, antic .... References Thiobarbiturates GABAA receptor positive allosteric modulators Allyl compounds {{sedative-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secobarbital
Secobarbital, sold under the brand name Seconal among others, is a short-acting barbiturate drug originally used for the treatment of insomnia. It was patented by Eli Lilly and Company in 1934 in the United States. It possesses anesthetic, anticonvulsant, anxiolytic, sedative, and hypnotic properties. In the United Kingdom, it was known as quinalbarbitone. Secobarbital is considered to be an obsolete sedative-hypnotic (sleeping pill) and has largely been replaced by the benzodiazepine family. It was widely abused, known on the street as "red devils" or "reds." Among barbiturates, secobarbital carries a particularly high risk of abuse and addiction, which is largely responsible for it falling out of use. Uses Medical Secobarbital is used for managing symptoms of epilepsy and for short-term treatment of insomnia. It is also used as a preoperative medication to produce anesthesia and anxiolysis for short surgical, diagnostic, or therapeutic procedures which are minimally painful. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methohexital
Methohexital or methohexitone (marketed under the brand names Brevital and Brietal) is a drug which is a barbiturate derivative. It is classified as short-acting, and has a rapid onset of action. It is similar in its effects to sodium thiopental, a drug with which it competed in the market for anesthetics. Pharmacology Methohexital binds to a distinct site which is associated with Cl− ionophores at GABAA receptors. This increases the length of time which the Cl− ionopores are open, thus causing an Inhibitory postsynaptic potential, inhibitory effect. Metabolism of methohexital is primarily hepatic via demethylation and oxidation. Side-chain oxidation is the primary means of metabolism involved in the termination of the drug's biological activity. Indications Methohexital is primarily used to induce anesthesia, and is generally provided as a sodium salt (i.e. methohexital sodium). It is only used in hospital or similar settings, under strict supervision. It has been commonl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allyl Group
In organic chemistry, an allyl group is a substituent with the structural formula . It consists of a methylene bridge () attached to a vinyl group (). The name is derived from the scientific name for garlic, . In 1844, Theodor Wertheim isolated an allyl derivative from garlic oil and named it "". The term allyl applies to many compounds related to , some of which are of practical or of everyday importance, for example, allyl chloride. Allylation is any chemical reaction that adds an allyl group to a substrate. Nomenclature A site adjacent to the unsaturated carbon atom is called the allylic position or allylic site. A group attached at this site is sometimes described as allylic. Thus, "has an allylic hydroxyl group". Allylic C−H bonds are about 15% weaker than the C−H bonds in ordinary sp3 carbon centers and are thus more reactive. Benzylic and allylic are related in terms of structure, bond strength, and reactivity. Other reactions that tend to occur with allyli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxide
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis.excerpt Transition metal alkoxides are widely used for coatings and as catalysts. Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols. Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a phe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbanion
In organic chemistry, a carbanion is an anion with a lone pair attached to a tervalent carbon atom. This gives the carbon atom a negative charge. Formally, a carbanion is the conjugate base of a carbon acid: : where B stands for the base (chemistry), base. The carbanions formed from deprotonation of alkanes (at an Orbital hybridisation#sp3, sp3 carbon), alkenes (at an Orbital hybridisation#sp2, sp2 carbon), arenes (at an sp2 carbon), and alkynes (at an Orbital hybridisation#sp, sp carbon) are known as alkyl, alkenyl (Vinyl group, vinyl), aryl, and alkynyl (acetylide) anions, respectively. Carbanions have a concentration of electron density at the negatively charged carbon, which, in most cases, reacts efficiently with a variety of electrophiles of varying strengths, including carbonyl groups, Imine, imines/Iminium, iminium salts, halogenating reagents (e.g., N-Bromosuccinimide, ''N''-bromosuccinimide and Iodine, diiodine), and Brønsted–Lowry acid–base theory, proton donors. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. ''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged Atomic nucleus, atomic nuclei. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of atoms. Neutral nucleophilic reactions with solvents such as Alcohol (chemistry), alcohols and water are named solvolysis. Nucleophiles may take part in nucleophilic substitution, whereby a nucleophile becomes attracted to a full or partial positive charge, and nucleophilic addition. Nucleophilicity is closely related to basicity. The difference between the two is, that basicity is a thermodynamic property (i.e. relates to an equilibrium state), but nucleop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
