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Duff Reaction
The Duff reaction or hexamine aromatic formylation is a formylation reaction used in organic chemistry for the synthesis of benzaldehydes with hexamine as the formyl carbon source. It is named after James Cooper Duff, who was a chemist at the College of Technology, Birmingham, around 1920–1950. The electrophilic species in this electrophilic aromatic substitution reaction is the iminium ion CH2+NR2. The initial reaction product is an iminium which is hydrolyzed to the aldehyde. See mechanism below. The reaction requires strongly electron donating substituents on the aromatic ring such as in a phenol. Formylation occurs '' ortho'' to the electron donating substituent preferentially, unless the ''ortho'' positions are blocked, in which case the formylation occurs at the ''para'' position. Examples are the synthesis of 3,5-di-''tert''-butylsalicylaldehyde: and the synthesis of syringaldehyde: If both ''ortho'' positions are vacant then a diformylation is possible, as in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duff Reaction
The Duff reaction or hexamine aromatic formylation is a formylation reaction used in organic chemistry for the synthesis of benzaldehydes with hexamine as the formyl carbon source. It is named after James Cooper Duff, who was a chemist at the College of Technology, Birmingham, around 1920–1950. The electrophilic species in this electrophilic aromatic substitution reaction is the iminium ion CH2+NR2. The initial reaction product is an iminium which is hydrolyzed to the aldehyde. See mechanism below. The reaction requires strongly electron donating substituents on the aromatic ring such as in a phenol. Formylation occurs '' ortho'' to the electron donating substituent preferentially, unless the ''ortho'' positions are blocked, in which case the formylation occurs at the ''para'' position. Examples are the synthesis of 3,5-di-''tert''-butylsalicylaldehyde: and the synthesis of syringaldehyde: If both ''ortho'' positions are vacant then a diformylation is possible, as in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formylation Reaction
A formylation reaction in organic chemistry refers to organic reactions in which an organic compound is functionalized with a formyl group (-CH=O). The reaction is a route to aldehydes (''C''-CH=O), formamides (''N''-CH=O), and formate esters (''O''-CH=O). A reagent that delivers the formyl group is called a formylating agent. A particularly important formylation process is hydroformylation which converts alkenes to the homologated aldehyde. The conversion of benzene to benzaldehyde is the basis of the Gattermann–Koch reaction: Aromatic formylation Formylation reactions are a form of electrophilic aromatic substitution and therefore work best when the aromatic starting materials are electron-rich. Phenols are very commonly encountered as they can be readily deprotonated to form phenoxides which are excellent nucleophiles, other electron rich substrates such as mesitylene, pyrrole, or fused aromatic rings can also be expected to react. Benzene will react under aggressive cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addition Reactions
Addition (usually signified by the plus symbol ) is one of the four basic operations of arithmetic, the other three being subtraction, multiplication and division. The addition of two whole numbers results in the total amount or '' sum'' of those values combined. The example in the adjacent image shows a combination of three apples and two apples, making a total of five apples. This observation is equivalent to the mathematical expression (that is, "3 ''plus'' 2 is equal to 5"). Besides counting items, addition can also be defined and executed without referring to concrete objects, using abstractions called numbers instead, such as integers, real numbers and complex numbers. Addition belongs to arithmetic, a branch of mathematics. In algebra, another area of mathematics, addition can also be performed on abstract objects such as vectors, matrices, subspaces and subgroups. Addition has several important properties. It is commutative, meaning that the order of the operands d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sommelet Reaction
The Sommelet reaction is an organic reaction in which a benzyl halide is converted to an aldehyde by action of hexamine and water. : One example, thiophene-2-carboxaldehyde is prepared by the reaction of hexamine with 2-chloromethylthiophene. The reaction is formally an oxidation of the carbon. Reaction mechanism and scope The benzyl halide 1 reacts with hexamine to a quaternary ammonium salt 3, each time just alkylating one nitrogen atom. Then the benzylammonium undergoes an acid-catalyzed hydrolysis process. : Depending on the hydrolysis conditions, the hexamine unit might instead break apart, leaving a benzyl amine (the Delépine reaction). The reaction can also be applied to the oxidation of benzylic amines. In this way, ''m''-xylylenediamine can be converted to isophthalaldehyde Isophthalaldehyde is an organic compound with the formula C6H4(CHO)2. It is one of three isomers of benzene di carbaldehyde, a reduced analog of phthalic acid. It is colorless, although c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bouveault Aldehyde Synthesis
The Bouveault aldehyde synthesis (also known as the Bouveault reaction) is a one-pot substitution reaction that replaces an alkyl or aryl halide with a formyl group using a ''N'',''N''-disubstituted formamide. For primary alkyl halides this produces the homologous aldehyde one carbon longer. For aryl halides this produces the corresponding carbaldehyde. The Bouveault aldehyde synthesis is an example of a formylation reaction, and is named for French scientist Louis Bouveault. : Reaction mechanism The first step of the Bouveault aldehyde synthesis is the formation of the Grignard reagent. Upon addition of a ''N'',''N''-disubstituted formamide (such as dimethylformamide) a hemiaminal is formed, which can easily be hydrolyzed into the desired aldehyde. Variations Variants using organolithium reagent In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duff Reaction Mechanism3
Duff may refer to: People * Duff (surname) * Duff (given name) * Duff (nickname) * Karen Duffy, an actress, model, and former MTV VJ once known as "Duff" * Duff Roman, on-air name of Canadian radio personality and executive David Mostoway (born 1938) Places * Duff, Indiana, United States, an unincorporated community * Duff, Nebraska, United States, an unincorporated community * Duff, Tennessee, United States, an unincorporated community * Duff, Saskatchewan, Canada, a village * Duff Hill, a mountain in County Wicklow, Ireland * Duff River, a river in County Sligo, Ireland * Duff Islands, in the Solomon Islands, Pacific Ocean * Mount Duff, Mangareva Island, French Polynesia * Mount Duff (Yakutat), a Canadian mountain on the border between Alberta and British Columbia * Duff Peak, Victoria Land, Antarctica * Duff Point, Greenwich Island, Antarctica Arts and entertainment * ''The DUFF'' (novel), by Kody Keplinger ** ''The DUFF'', a 2015 film based on the Keplinger novel * Duff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methine
In organic chemistry, a methine group or methine bridge is a trivalent functional group , derived formally from methane. It consists of a carbon atom bound by two single bonds and one double bond, where one of the single bonds is to a hydrogen. The group is also called methyne or methene; its IUPAC systematic name is methylylidene or methanylylidene (2007''Methanylylidene group''in the Chemical Entities of Biological Interest (ChEBI) database. Accessed on 2015-03-05. This group is sometimes called "methylidyne", however that name belongs properly to either the methylidyne group (connected to the rest of the molecule by a triple bond) or to the methylidyne radical (the two atoms as a free molecule with dangling bonds). The name "methine" is also widely used in non-systematic nomenclature for the methanetriyl group (IUPAC): a carbon atom with four single bonds, where one bond is to a hydrogen (). (2007''Methanetriyl group''in the Chemical Entities of Biological Interest (Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Mechanism
In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible, and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction. It also describes each reactive intermediate, activated complex, and transition state, and which bonds are broken (and in what order), and which bonds are formed (and in what order). A complete mechanism must also explain the reason for the reactants and catalyst used, the stereochemistry observed in reactants and products, all products formed and the amount of each. The electron or arrow pushing method is often used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-cresol
''para''-Cresol, also 4-methylphenol, is an organic compound with the formula CH3C6H4(OH). It is a colourless solid that is widely used intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of ''o''-cresol and ''m''-cresol. Production Together with many other compounds, ''p''-cresol is conventionally extracted from coal tar, the volatilized materials obtained in the roasting of coal to produce coke. This residue contains a few percent by weight of phenol and cresols. Industrially, ''p''-cresol is currently prepared mainly by a two-step route beginning with the sulfonation of toluene: :CH3C6H5 + H2SO4 → CH3C6H4SO3H + H2O Basic hydrolysis of the sulfonate salt gives the sodium salt of the cresol: :CH3C6H4SO3H + 2 NaOH → CH3C6H4OH + Na2SO3 + H2O Other methods for the production of ''p''-cresol include chlorination of toluene followed by hydrolysis. In the cymene-cresol process, toluene is alkylated with propene to give ''p''- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
