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Pivalate Ester
Pivalic acid is a carboxylic acid with a molecular formula of (CH3)3CCO2H. This colourless, odoriferous organic compound is solid at room temperature. Two abbreviations for pivalic acid are ''t''-BuC(O)OH and PivOH. The pivalyl or pivaloyl group is abbreviated ''t''-BuC(O). Pivalic acid is an isomer of valeric acid, the other two isomers of it are 2-Methylbutanoic acid, 2-methylbutanoic acid and 3-Methylbutanoic acid, 3-methylbutanoic acid. Preparation Pivalic acid is prepared on a commercial scale by hydrocarboxylation of isobutene via the Koch reaction: :(CH3)2C=CH2 + CO + H2O → (CH3)3CCO2H Such reactions require an acid catalyst such as hydrogen fluoride. tert-Butyl alcohol, ''tert''-Butyl alcohol and isobutyl alcohol can also be used in place of isobutene. Globally, several million kilograms are produced annually. Pivalic acid is also economically recovered as a byproduct from the production of semisynthetic penicillins like ampicillin and amoxycillin. It was originally pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol (chemistry)
In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sugar alcohols and cholesterol. The presence of an OH group strongly modifies the properties of Hydrocarbon, hydrocarbons, conferring Hydrophile, hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur. History The flammable nature of the exhalations of wine was already known to ancient natural philosophers such as Aristotle (384–322 BCE), Theophrastus (–287 BCE), and Pliny the Elder (23/24–79 CE). However, this did not immediately lead to the isolation of alcohol, even despite the development of more advanced distillation techniques in second- and third-century Roman Egypt. An important recognition, first found in one of the writings attributed to Jabir ibn Hayyan, J� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutyl Alcohol
Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as ''i''-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Its isomers are 1-butanol, 2-butanol, and ''tert''-butanol, all of which are important industrially. History and occurrence Fusel alcohols including isobutanol are grain fermentation byproducts. Therefore, trace amounts of isobutanol may be present in many alcoholic beverages. In 1852 Charles Adolphe Wurtz subjected such alcohols to fractional distillation and identified in some of them a butylic alcohol boiling at around 108°C. Its structure was initially unclear, with some chemists believing it corresponded to butyric acid, but theoretical considerations indicated that normal butanol should have a higher boiling point, and in 1867 Emil Erlenmeyer and independently Vladimir Markovnikov determined its actual s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSS (NMR Standard)
Sodium trimethylsilylpropanesulfonate (DSS) is the organosilicon compound with the formula (CH3)3SiCH2CH2CH2SO3−Na+. It is the sodium salt of trimethylsilylpropanesulfonic acid. A white, water-soluble solid, it is used as a chemical shift standard for proton NMR spectroscopy of aqueous solutions. The chemical shift, specifically the signal for the trimethylsilyl group, is relatively insensitive to pH. The proton spectrum of DSS also exhibits resonances at 2.91 ppm (m), 1.75 ppm (m), and 0.63 ppm (m) at an intensity of 22% of the reference resonance at 0 ppm. Alternatives Sodium trimethylsilyl propionate (TSP) is a related compound used as an NMR standard. It uses a carboxylic acid instead of the sulfonic acid In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ... found in DSS t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinyl Alcohol
Vinyl alcohol, also called ethenol (IUPAC name; not ethanol) or ethylenol, is the simplest enol. With the formula , it is a labile compound that converts to acetaldehyde immediately upon isolation near room temperature. It is not a practical precursor to any compound. Synthesis Vinyl alcohol can be formed by the pyrolytic elimination of water from ethylene glycol at a temperature of 900 °C and low pressure. Such processes are of no practical importance. Tautomerization of vinyl alcohol to acetaldehyde Under normal conditions, vinyl alcohol converts (tautomerizes) to acetaldehyde: : At room temperature, acetaldehyde () is more stable than vinyl alcohol () by 42.7 kJ/mol. Vinyl alcohol gas isomerizes to the aldehyde with a half-life of 30 min at room temperature. : The uncatalyzed keto–enol tautomerism by a 1,3-hydrogen migration is forbidden by the Woodward–Hoffmann rules and therefore has a high activation barrier and is not a significant pathway at or near room ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinctive functional group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides), but not according to the IUPAC. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Lactones are cyclic carboxylic esters; naturally occurring lactones are mainly 5- and 6-membered ring lactones. Lactones contribute to the aroma of fruits, butter, cheese, vegetables like celery and other foods. Esters can be formed from oxoacids (e.g. esters of acetic acid, carbonic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylation Of Alkyl Magnesium Halides
Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylation, especially when applied to the reaction of carbanionic reagents with CO2. More generally, carbonation usually describes the production of carbonates. Organic chemistry Carboxylation is a standard conversion in organic chemistry. Specifically carbonation (i.e. carboxylation) of Grignard reagents and organolithium compounds is a classic way to convert organic halides into carboxylic acids. Sodium salicylate, precursor to aspirin, is commercially prepared by treating sodium phenolate (the sodium salt of phenol) with carbon dioxide at high pressure (100 atm) and high temperature (390 K) – a method known as the Kolbe-Schmitt reaction. Acidification of the resulting salicylate salt gives salicylic acid. : Many detailed procedures are desc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tert-Butyl Chloride
''tert''-Butyl chloride is the organochloride with the formula . It is a colorless, flammable liquid. It is sparingly soluble in water, with a tendency to undergo hydrolysis to the corresponding ''tert''-butyl alcohol. It is produced industrially as a precursor to other organic compounds.M. Rossberg et al. "Chlorinated Hydrocarbons" in ''Ullmann's Encyclopedia of Industrial Chemistry'' 2006, Wiley-VCH, Weinheim. Synthesis ''tert''-Butyl chloride is produced by the reaction of ''tert''-butyl alcohol with hydrogen chloride. In the laboratory, concentrated hydrochloric acid is used. The conversion entails a SN1 reaction as shown below.James F. Norris and Alanson W. Olmsted "''tert''-Butyl Chloride" Org. Synth. 1928, volume 8, pp. 50. The overall reaction, therefore, is: : Because ''tert''-butanol is a tertiary alcohol, the relative stability of the ''tert''-butyl carbocation in the step 2 allows the SN1 mechanism to be followed, whereas a primary alcohol would follow an S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grignard Reagent
Grignard reagents or Grignard compounds are chemical compounds with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide . They are a subclass of the organomagnesium compounds. Grignard compounds are popular reagents in organic synthesis for creating new carbon–carbon bonds. For example, when reacted with another halogenated compound in the presence of a suitable catalyst, they typically yield and the magnesium halide as a byproduct; and the latter is insoluble in the solvents normally used. Grignard reagents are rarely isolated as solids. Instead, they are normally handled as solutions in solvents such as diethyl ether or tetrahydrofuran using air-free techniques. Grignard reagents are complex with the magnesium atom bonded to two ether ligands as well as the halide and organyl ligands. The discovery of the Grignard reaction in 1900 was recogn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivalonitrile
Pivalonitrile is a nitrile with the semi-structural formula (CH3)3CCN, abbreviated ''t''-BuCN. This aliphatic organic compound is a clear, colourless liquid that is used as a solvent and as a labile ligand in coordination chemistry A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' .... Pivalonitrile is isomeric with ''tert''-butyl isocyanide but the two compounds do not exist in chemical equilibrium, unlike its silicon analog trimethylsilyl cyanide. References 5 Tert-butyl compounds {{alkanederivative-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetone2pinacolone (cropped)
Acetone (2-propanone or dimethyl ketone) is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile, and flammable liquid with a characteristic pungent odor. Acetone is miscible with water and serves as an important organic solvent in industry, home, and laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and for production of methyl methacrylate and bisphenol A, which are precursors to widely used plastics.Acetone World Petrochemicals report, January 2010Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. It is a common building block in |
