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β-naphthol
2-Naphthol, or β-naphthol, is a fluorescence, fluorescent colorless (or occasionally yellow) crystalline solid with the formula C10H7OH. It is an isomer of 1-Naphthol, 1-naphthol, differing by the location of the hydroxide, hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, but more reactive. Both isomers are soluble in simple Alcohol (chemistry), alcohols, ethers, and chloroform. 2-Naphthol is a widely used intermediate for the production of dyes and other compounds. Production Traditionally, 2-naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid:full-text PDF/ref> :C10H8 + H2SO4 → C10H7SO3H + H2O The sulfonic acid group is then cleaved in molten sodium hydroxide: :C10H7(SO3H) + 3 NaOH → C10H7ONa + Na2SO3 + 2 H2O Neutralization of the product with acid gives 2-naphthol. 2-Naphthol can also be produced by a method analogous to the cumene process. 2-Naphthol-deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harmful
Harmful was a rock band from Frankfurt, Germany, founded in 1992 and frequently compared to early Helmet and more occasionally to Blackmail.sefor an overview of reviewer opinions The band has released eight albums to date, the first two and the last three on independent labels ( BluNoise, Steamhammer and Nois-o-lution), the third (which was produced by Dave Sardy, who also produced the latest album ''Cause'') and fourth via BMG. 2007 saw the release of Harmful's seventh album, aptly titled ''7'', produced by Billy Gould, former member of Faith No More. Gould has subsequently joined the band as a fourth member and also took part in the tour supporting the album in early 2007. In the past, Harmful has toured with bands like Slayer, Machine Head, Clutch, Paradise Lost, Therapy?, LaFaro, and Helmet. The band disbanned in 2014, after touring for their last album ''Sick and tired of being sick and tired.'' Discography * 1995: ''Harmful'' ( BluNoise) * 1997: ''Apoplexy.136'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudan I
Sudan I (also known as CI Solvent Yellow 14 or Solvent Orange R) is an organic compound typically classified as an azo dye. It is an orange-red solid, used to color waxes, oils, petrol, solvents, and polishes. Historically, Sudan I used to serve as a food coloring agent, notably for curry powder and chili powder. However, along with its derivatives Sudan III and Sudan IV, the compound has been banned for use in food in many countries (including the United States and the European Union) due to its classification as a category 3 carcinogen by the International Agency for Research on Cancer (not classifiable as to its carcinogenicity in humans). Nevertheless, Sudan I remains valuable as a coloring reagent for non-food-related uses, such as in the formulation of orange-colored smoke. Application The Sudan dyes are a group of azo compounds which have been used to color hydrocarbon solvents, oils, fats, waxes, shoes, and floor polishes. As recently as 1974, about of Sudan I, of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Naphthalenethiol
2-Naphthalenethiol is an organosulfur compound with the formula C10H7SH. It is a white solid. It is one of two monothiols of naphthalene Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white Crystal, crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 Parts-per notation ..., the other being 1-naphthalenethiol. Synthesis and reactions 2-Naphthalenethiol is prepared from 2-naphthol by the Newman–Kwart rearrangement starting from a thiocarbamate. It undergoes lithiation at the 1 and 3-position. It can be used as a flavouring agent and has been described as having an “artichoke”, “meaty” and “creamy” taste”. References {{DEFAULTSORT:Naphthalenethiol, 2- Thiols 2-Naphthyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CuCl2 Naphthol Coupling
Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride (CuCl2). History Copper(I) chloride was first prepared by Robert Boyle and designated rosin of copper in the mid-seventeenth century from mercury(II) chloride ("Venetian sublimate") and copper metal: :HgCl2 + 2 Cu → 2 CuCl + Hg In 1799, Joseph Proust first differentiated two different chlorides of copper. He prepared CuCl (which he called white muriate of copper) by heating CuCl2 at red heat in the absence of air, causing it to lose half of its combined chlorine followed by removing residual CuCl2 by washing with water. An acidic solution of CuCl was formerly used to analyze carbon monoxide content in gases, for example in Hempel's gas apparatus where the CuCl absorbs the carbon mono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asymmetric Catalysis
Enantioselective synthesis, also called asymmetric synthesis, is a form of chemical synthesis. It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of Chirality (chemistry), chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric or diastereomeric) products in Enantiomeric excess, unequal amounts." Put more simply: it is the synthesis of a compound by a method that favors the formation of a specific enantiomer or diastereomer. Enantiomers are stereoisomers that have opposite configurations at every chiral center. Diastereomers are stereoisomers that differ at one or more chiral centers. Enantioselective synthesis is a key process in modern chemistry and is particularly important in the field of pharmaceuticals, as the different enantiomers or diastereomers of a molecule often have different biological activity. Overview Many of the building blocks of biological systems such as sugars a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C2-Symmetric Ligands
In homogeneous catalysis, ''C''2-symmetric ligands refer to ligands that lack mirror symmetry but have ''C''2 symmetry (two-fold rotational symmetry). Such ligands are usually bidentate and are valuable in catalysis. The ''C''2 symmetry of ligands limits the number of possible reaction pathways and thereby increases enantioselectivity, relative to asymmetrical analogues. ''C''2-symmetric ligands are a subset of chiral ligands. Chiral ligands, including ''C''2-symmetric ligands, combine with metals or other groups to form chiral catalysts. These catalysts engage in enantioselective chemical synthesis, in which chirality in the catalyst yields chirality in the reaction product. Examples An early ''C''2-symmetric ligand, diphosphine catalytic ligand DIPAMP, was developed in 1968 by William S. Knowles and coworkers of Monsanto Company, who shared the 2001 Nobel Prize in Chemistry. This ligand was used in the industrial production of -DOPA. : Some classes of ''C''2-symmetric li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-aminonaphthalene
2-Naphthylamine or 2-aminonaphthalene is one of two isomeric aminonaphthalenes, compounds with the formula C10H7NH2. It is a colorless solid, but samples take on a reddish color in air because of oxidation. It was formerly used to make azo dyes, but it is a known carcinogen and has largely been replaced by less toxic compounds.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. . Preparation 2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C, the Bucherer reaction. Its acetyl derivative can be obtained by heating 2-naphthol with ammonium acetate to 270-280 °C. Reactions It gives no color with iron(III) chloride. When reduced by sodium in boiling amyl alcohol solution, it forms tetrahydro-3-naphthylamine, which exhibits the properties of the aliphatic amines in that it is strongly alkaline in reaction, has an ammoniacal odor and cannot be diazotized. On oxidation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bucherer Reaction
The Bucherer reaction in organic chemistry is the reversible conversion of a naphthol to a naphthylamine in the presence of ammonia and sodium bisulfite. The reaction is widely used in the synthesis of dye precursors aminonaphthalenesulfonic acids. :C10H7-2-OH + NH3 C10H7-2-NH2 + H2O The French chemist Robert Lepetit was the first to discover the reaction in 1898. The German chemist Hans Theodor Bucherer (1869–1949) discovered (independent from Lepetit) its reversibility and its potential especially in industrial chemistry. Bucherer published his results in 1904 and his name is connected to this reaction. The organic reaction also goes by the name Bucherer-Lepetit reaction or (incorrectly) the Bucherer-Le Petit reaction. The reaction is used to convert 1,7-dihydroxynaphthalene into 7-amino-1-naphthol and 1-aminonaphthalene-4-sulfonic acid into 1-hydroxynaphthalene-4-sulfonic acid. It is also useful for transamination reactions of 2-aminonaphthalenes. Mechanism I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naphthol AS
Naphthol AS is an organic compound with the formula C10H6(OH)C(O)NHC6H5. It is the anilide of 3-hydroxy-2-carboxynaphthalene. Many analogous compounds are known, designated with a differing suffix. For example, in Naphthol AS-OL, the aryl substituent on nitrogen is C6H4-2-OCH3. These compounds are used as coupling partners in the preparation of some azo dye Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C−N=N−C l ...s. History In 1911, it was found to be a good precursor to dyes for wool by chemists at K. Oehler Anilin- und Anilinfarbenfabrik Offenbach. References Organic pigments Azo dyes Amides {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Red O
Oil Red O (Solvent Red 27, Sudan Red 5B, C.I. 26125, C26H24N4O) is a lysochrome (fat-soluble dye) diazo dye used for staining of neutral triglycerides and lipids on frozen sections and some lipoproteins on paraffin sections. It has the appearance of a red powder with an absorbance maximum at 518 nanometers. Uses Oil Red O is one of the dyes used for Sudan staining. Similar dyes include Sudan III, Sudan IV, and Sudan Black B. The staining has to be performed on fresh samples, as alcohol fixation removes most lipids. Oil Red O largely replaced Sudan III and Sudan IV, as it provides much deeper red color and the stains are therefore much easier to see. Oil Red O can be used to mark lipid-containing vacuoles, particularly in cases of acute lymphoblastic leukemia or Burkitt's lymphoma. It can also be used to stain liver sections for histological analysis, quantify cell lipid content, and to stain the aorta to examine lesions from atherosclerosis. In pyrotechnics, Oil Red O is use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
