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Phthalimides
Phthalimide is the organic compound with the formula C6H4(CO)2NH. It is the imide derivative of phthalic anhydride. It is a sublimable white solid that is slightly soluble in water but more so upon addition of base. It is used as a precursor to other organic compounds as a masked source of ammonia. Preparation Phthalimide can be prepared by heating phthalic anhydride with alcoholic ammonia giving 95–97% yield. Alternatively, it may be prepared by treating the anhydride with ammonium carbonate or urea. It can also be produced by ammoxidation of ''o''-xylene. Uses Phthalimide is used as a precursor to anthranilic acid, a precursor to azo dyes and saccharin. Alkyl phthalimides are useful precursors to amines in chemical synthesis, especially in peptide synthesis where they are used "to block both hydrogens and avoid racemization of the substrates". Alkyl halides can be converted to the N-alkylphthalimide: : C6H4(CO)2NH + RX + NaOH → C6H4(CO)2NR + NaX + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabriel Synthesis
The Gabriel synthesis is a chemical reaction that transforms primary alkyl halides into primary amines. Traditionally, the reaction uses potassium phthalimide. The reaction is named after the German chemist Siegmund Gabriel. The Gabriel reaction has been generalized to include the alkylation of sulfonamides and imides, followed by deprotection, to obtain amines (see Gabriel synthesis#Alternative Gabriel reagents, Alternative Gabriel reagents). The alkylation of ammonia is often an unselective and inefficient route to amines. In the Gabriel method, phthalimide anion is employed as a surrogate of H2N−. Traditional Gabriel synthesis In this method, the sodium or potassium salt of phthalimide is ''N''-alkylated with a primary alkyl halide to give the corresponding ''N''-alkylphthalimide. Upon workup by acidic hydrolysis the primary amine is liberated as the amine salt. Alternatively the workup may be via the Ing–Manske procedure, involving reaction with hydrazine. This metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Phthalimide
Potassium phthalimide is a chemical compound of formula C8H4KNO2. It is the potassium salt of phthalimide, and usually presents as fluffy, very pale yellow crystals. It can be prepared by adding a hot solution of phthalimide in ethanol to a solution of potassium hydroxide in ethanol; the desired product precipitates. This compound is a commercially available reagent used in the Gabriel synthesis of amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen Hydrogen is the chemical element wi ...s. References Potassium compounds Phthalimides {{Organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is a medication used to treat a number of cancers (including multiple myeloma), graft-versus-host disease, and a number of skin conditions including complications of leprosy. While it has been used in a number of HIV-associated conditions, such use is associated with increased levels of the virus. It is taken by mouth. Common side effects include sleepiness, rash, and dizziness. Severe side effects include tumor lysis syndrome, blood clots, and peripheral neuropathy. Use in pregnancy may harm the fetus, including resulting in malformation of the limbs. In males who are taking the medication, contraception is essential if a partner could become pregnant. It is an immunomodulatory medication and works by a number of mechanisms, including stimulating T cells and decreasing TNF-α production. Thalidomide was first marketed in 1957 in West Germany, where it was available over the counter. When first r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amide
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid () with the hydroxyl group () replaced by an amine group (); or, equivalently, an acyl (alkanoyl) group () joined to an amine group. Common examples of amides are acetamide (), benzamide (), and dimethylformamide (). Amides are qualified as primary, secondary, and tertiary according to whether the amine subgroup has the form , , or , where R and R' are groups other than hydrogen. The core of amides is called the amide group (specifically, carboxamide group). Amides are pervasive in nature and technology. Proteins and important plastics l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharin
Saccharin (''aka'' saccharine, Sodium sacchari) is an artificial sweetener with effectively no nutritional value. It is about 550 times as sweet as sucrose but has a bitter or metallic aftertaste, especially at high concentrations. Saccharin is used to sweeten products such as drinks, candies, cookies, and especially for masking bitter taste of some medicines. Etymology Saccharin derives its name from the word "saccharine", meaning "sugary". The word saccharine is used figuratively, often in a derogative sense, to describe something "unpleasantly over-polite" or "overly sweet". Both words are derived from the Greek word (''sakkharon'') meaning "gravel". Similarly, saccharose is an obsolete name for sucrose (table sugar). Properties Saccharin is heat-stable. It does not react chemically with other food ingredients; as such, it stores well. Blends of saccharin with other sweeteners are often used to compensate for each sweetener's weaknesses and faults. A 10:1 cyclamate–sacch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (GGU, GGC, GGA, GGG). Glycine is integral to the formation of alpha-helices in secondary protein structure due to its compact form. For the same reason, it is the most abundant amino acid in collagen triple-helices. Glycine is also an inhibitory neurotransmitter – interference with its release within the spinal cord (such as during a ''Clostridium tetani'' infection) can cause spastic paralysis due to uninhibited muscle contraction. It is the only achiral proteinogenic amino acid. It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom. History and etymology Glycine was discovered in 1820 by the French chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Hydroxide
Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exploit its caustic nature and its reactivity toward acids. An estimated 700,000 to 800,000 tonnes were produced in 2005. KOH is noteworthy as the precursor to most soft and liquid soaps, as well as numerous potassium-containing chemicals. It is a white solid that is dangerously corrosive. Properties and structure KOH exhibits high thermal stability. Because of this high stability and relatively low melting point, it is often melt-cast as pellets or rods, forms that have low surface area and convenient handling properties. These pellets become tacky in air because KOH is hygroscopic. Most commercial samples are ca. 90% pure, the remainder being water and carbonates. Its dissolution in water is strongly exothermic. Concentrated aqueous solut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Carbonate
Potassium carbonate is the inorganic compound with the formula K2 CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass. History Potassium carbonate is the primary component of potash and the more refined pearl ash or salts of tartar. Historically, pearl ash was created by baking potash in a kiln to remove impurities. The fine, white powder remaining was the pearl ash. The first patent issued by the US Patent Office was awarded to Samuel Hopkins in 1790 for an improved method of making potash and pearl ash. In late 18th-century North America, before the development of baking powder, pearl ash was used as a leavening agent for quick breads. Production Potassium carbonate is prepared commercially by the reaction potassium hydroxide with carbon dioxide: : 2 KOH + CO2 → K2CO3 + H2O From the solution crystallizes the sesquihydrate K2CO3·H2O ("potash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic
In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carries a partial positive charge, or have an atom that does not have an octet of electrons. Electrophiles mainly interact with nucleophiles through addition and substitution reactions. Frequently seen electrophiles in organic syntheses include cations such as H+ and NO+, polarized neutral molecules such as HCl, alkyl halides, acyl halides, and carbonyl compounds, polarizable neutral molecules such as Cl2 and Br2, oxidizing agents such as organic peracids, chemical species that do not satisfy the octet rule such as carbenes and radicals, and some Lewis acids such as BH3 and DIBAL. Organic chemistry Addition of halogens These occur between alkenes and electrophiles, often halogens as in halogen addition reactions. Common reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folpet
Folpet is the tradename for the organic compound with the formula C6H4(CO)2NSCCl3. It is a fungicide derived from phthalimide (C6H4(CO)2N-) and trichloromethylsulfenyl chloride. The compound is white although commercial samples can appear brownish. It is structurally related to Captan, which is also a trichloromethylsulfenyl-containing fungicide. Resistance folpet resistance is still unheard of due to its multiple effects. However, in 2001 some degree of ''cross''-resistance was reported in iprodione-resistant South African ''Botrytis cinerea'' on grape. References {{reflist, refs= {{cite web , title=Folpet: the essential multi-site fungicide , website=ADAMA UK , url=http://www.adama.com/uk/en/news-and-media/adama-news/folpet-the-essential-multi-site-fungicide , access-date=2021-03-13 , date=2019-12-11 {{cite journal , last1=Fourie , first1=P.H. , last2=Holz , first2=G. , title=Incomplete Cross-Resistance to Folpet and Iprodione in ''Botrytis cinerea'' from Grape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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