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3-Chloropyridine Synthesis Via Pyrolysis
3-Chloropyridine is an aryl chloride and isomer of chloropyridine with the formula C5H4ClN. It is a colorless liquid that is mainly used as a building block in organic synthesis. The compound is a substrate for many coupling processes including the Heck reaction, Suzuki reaction, and Ullmann reaction. Preparation 3-Chloropyridine may be prepared by the direct chlorination of pyridine with aluminium chloride used as the catalyst. The yield is 33%. A less expensive way of preparing 3-chloropyridine consists of the gas phase pyrolysis of a mixture of pyrrole and chloroform in an empty glass tube. The molar ratio of the reagents is one to five. The yields range from 25 to 33%. A little 2-chloropyridine is formed as a side product. The process is thought to be an example of the Ciamician–Dennstedt rearrangement Pyridine is a basic (chemistry), basic heterocyclic compound, heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Chloropyridine
2-Chloropyridine is an aryl chloride with the formula C5H4ClN. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It also serves to generate antihistamines and antiarrythymics for pharmaceutical purposes. It is one of three isomers of chloropyridine. Preparation : 2-Chloropyridine is produced by direct reaction of pyridine with chlorine. The initially formed 2-chloropyridine reacts further to give 2,6-Dichloropyridine, 2,6-dichloropyridine. Alternatively, 2-chloropyridines can be conveniently synthesized in high yields from pyridine-N-oxides. 2-Chloropyridine was originally prepared by the chlorination of 2-hydroxypyridine with phosphoryl chloride. Main reactions and applications 2-Chloropyridine reacts with nucleophiles to generate pyridine derivatives substituted at the second and fourth carbons on the heterocycle. Therefore, many reactions using 2-chloropyridine generate mixtures of products which require further workup to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-Bromopyridine
3-Bromopyridine is an aryl bromide and isomer of bromopyridine with the formula C5H4BrN. It is a colorless liquid that is mainly used as a building block in organic synthesis. It participates as a substrate in many reactions associated with aryl halides, e.g., the Heck reaction and Buchwald–Hartwig amination In organic chemistry, the Buchwald–Hartwig amination is a chemical reaction for the synthesis of carbon–nitrogen bonds via the cross-coupling reaction, palladium-catalyzed coupling reactions of amines with aryl halides. Although Pd-catalyzed .... References 3-Pyridyl compounds Bromoarenes {{DEFAULTSORT:Bromopyridine, 3- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryl Chloride
In organic chemistry, an aryl halide (also known as a haloarene) is an aromatic compound in which one or more hydrogen atoms directly bonded to an aromatic ring are replaced by a halide ion (such as fluorine F''−'', chlorine Cl−1,−3,−5, bromine Br−1, or iodine I−). Aryl halides are distinct from haloalkanes (alkyl halides) due to significant differences in their methods of preparation, chemical reactivity, and physical properties. The most common and important members of this class are aryl chlorides, but the group encompasses a wide range of derivatives with diverse applications in organic synthesis, pharmaceuticals, and materials science. Classification according to halide Aryl fluorides Aryl fluorides are used as synthetic intermediates, e.g. for the preparation of pharmaceuticals, pesticides, and liquid crystals. The conversion of diazonium salts is a well established route to aryl fluorides. Thus, anilines are precursors to aryl fluorides. In the classic Schiemann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloropyridine
Chloropyridines are a group of aryl chlorides consisting of a pyridine ring with chlorine atoms as substituents. Chloropyridines include: *2-Chloropyridine * 3-Chloropyridine * 4-Chloropyridine * 2,6-Dichloropyridine Production Direct halogenation of pyridine with chlorine gas above 270 °C gives a mixture of 2-chloropyridine and 2,6-dichloropyridine. 2- and 4-chloropyridine are prepared from the corresponding pyridinols using phosphoryl chloride. Uses Chloropyridines are important intermediates to pharmaceuticals and agrochemicals. A major use of 2-chloropyridine is the production of production of the fungicide pyrithione. Reaction of 4-chloropyridine with thioglycolic acid gives pyridylmercaptoacetic acid, a step in the production of cephalosporin antibiotics. See also *Bromopyridine Bromopyridines are a group of aryl bromides consisting of a pyridine ring with bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heck Reaction
The Heck reaction (also called the Mizoroki–Heck reaction) is the chemical reaction of an unsaturated halide (or triflate) with an alkene in the presence of a base and a palladium catalyst to form a substituted alkene. It is named after Tsutomu Mizoroki and Richard F. Heck. Heck was awarded the 2010 Nobel Prize in Chemistry, which he shared with Ei-ichi Negishi and Akira Suzuki, for the discovery and development of this reaction. This reaction was the first example of a carbon-carbon bond-forming reaction that followed a Pd(0)/Pd(II) catalytic cycle, the same catalytic cycle that is seen in other Pd(0)-catalyzed cross-coupling reactions. The Heck reaction is a way to substitute alkenes. History The original reaction by Tsutomu Mizoroki (1971) describes the coupling between iodobenzene and styrene in methanol to form stilbene at 120 °C ( autoclave) with potassium acetate base and palladium chloride catalysis. This work was an extension of earlier work by Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suzuki Reaction
The Suzuki reaction or Suzuki coupling is an organic reaction that uses a palladium complex catalyst to cross-couple a boronic acid to an organohalide. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of noble metal catalysis in organic synthesis. This reaction is sometimes telescoped with the related Miyaura borylation; the combination is the Suzuki–Miyaura reaction. It is widely used to synthesize poly olefins, styrenes, and substituted biphenyls. The general scheme for the Suzuki reaction is shown below, where a carbon–carbon single bond is formed by coupling a halide (R1-X) with an organoboron species (R2-BY2) using a palladium catalyst and a base. The organoboron species is usually synthesized by hydroboration or carboboration, allowing for rapid generation of molecular complexity. Several reviews have been publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ullmann Reaction
The Ullmann reaction or Ullmann coupling, named after Fritz Ullmann, couples two aryl or alkyl groups with the help of copper. The reaction was first reported by Ullmann and his student Bielecki in 1901. It has been later shown that palladium and nickel can also be effectively used. Aryl-Aryl bond formation is a fundamental tool in modern organic synthesis, with applications spanning natural product synthesis, Medication, pharmaceuticals, agrochemicals, and the development of commercial dyes and Polycyclic aromatic hydrocarbon, polyaromatics. With over a century of history, the Ullmann reaction has been one of the first to use a transition metal, primarily copper, in its higher oxidation states. Despite the significant implications of biaryl coupling in industries, the Ullmann reaction was plagued by a number of problems in its early development. However, in modern times the Ullmann reaction has revived interest due to several advantages of copper over other catalytic metals. Mec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridine
Pyridine is a basic (chemistry), basic heterocyclic compound, heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom . It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless, but older or impure samples can appear yellow, due to the formation of extended, unsaturated Polymer, polymeric chains, which show significant electrical conductivity. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Historically, pyridine was produced from coal tar. As of 2016, it is synthesized on the scale of about 20,000 tons per year worldwide. Properties Physical properties Pyridine is diamagnetism, diamagnetic. Its critical point (thermodynamics), critical parameters are: pressure 5.63 MPa, temperature 619 K and volume 248 cm3/mol. In the temperatur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Chloride
Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms a hexahydrate with the formula , containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are colourless crystals, but samples are often contaminated with iron(III) chloride, giving them a yellow colour. The anhydrous form is commercially important. It has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium, but large amounts are also used in other areas of the chemical industry. The compound is often cited as a Lewis acid. It is an inorganic compound that reversibly changes from a polymer to a monomer at mild temperature. Structure Anhydrous adopts three structures, depending on the temperature and the state (solid, liquid, gas). Solid has a sheet-like layered structure with cubic close-packed chloride ions. In this framework, the Al centres exhibit octahedral coordination geom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic, aromatic, organic compound, a five-membered ring with the formula . It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, . Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties, structure, bonding Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroform
Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and polytetrafluoroethylene (PTFE). Chloroform was once used as an inhalational anesthetic between the 19th century and the first half of the 20th century. It is miscible with many solvents but it is only very slightly soluble in water (only 8 g/L at 20°C). Structure and name The molecule adopts a tetrahedral molecular geometry with C3v symmetry. The chloroform molecule can be viewed as a methane molecule with three hydrogen atoms replaced with three chlorine atoms, leaving a single hydrogen atom. The name "chloroform" is a portmanteau of ''terchloride'' (tertiary chloride, a trichloride) and ''formyle'', an obsolete name for the methylylidene radical (CH) derived from formic acid. Natural occurrence Many kinds of seaweed produce chlor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-chloropyridine
2-Chloropyridine is an aryl chloride with the formula C5H4ClN. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It also serves to generate antihistamines and antiarrythymics for pharmaceutical purposes. It is one of three isomers of chloropyridine. Preparation : 2-Chloropyridine is produced by direct reaction of pyridine with chlorine. The initially formed 2-chloropyridine reacts further to give 2,6-Dichloropyridine, 2,6-dichloropyridine. Alternatively, 2-chloropyridines can be conveniently synthesized in high yields from pyridine-N-oxides. 2-Chloropyridine was originally prepared by the chlorination of 2-hydroxypyridine with phosphoryl chloride. Main reactions and applications 2-Chloropyridine reacts with nucleophiles to generate pyridine derivatives substituted at the second and fourth carbons on the heterocycle. Therefore, many reactions using 2-chloropyridine generate mixtures of products which require further workup to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
