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3-Methylpyridine
3-Methylpyridine or 3-picoline, is an organic compound with formula 3-CH3C5H4N. It is one of three positional isomers of methylpyridine, whose structures vary according to where the methyl group is attached around the pyridine ring. This colorless liquid is a precursor to pyridine derivatives that have applications in the pharmaceutical and agricultural industries. Like pyridine, 3-methylpyridine is a colorless liquid with a strong odor and is classified as a weak base. Synthesis 3-Methylpyridine is produced industrially by the reaction of acrolein, with ammonia. These ingredients are combined as gases which flows over an oxide-based heterogeneous catalyst. The reaction is multistep, culminating in cyclisation. :2 CH2CHCHO + NH3 → CH3C5H4N + 2H2O This process also affords substantial amounts of pyridine, which arises by demethylation of the 3-methylpyridine. A route that gives better control of the product starts with acrolein, propionaldehyde, and ammonia: :CH2CHCHO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Methylglutaronitrile
2-Methylglutaronitrile is the organic compound with the formula NCCH2CH2CH(CH3)CN. This dinitrile is obtained in the large-scale synthesis of adiponitrile. It is a colorless liquid with an unpleasant odor. It is the starting compound for the vitamin nicotinamide and for the diester dimethyl-2-methylglutarate and the ester amide methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate, which are promoted as green solvents. 2-Methylglutaronitrile is chiral but is mainly encountered as the racemate. Occurrence and production 2-Methylglutaronitrile is a by-product of the production of adiponitrile, the precursor of hexamethylenediamine and adipic acid as building blocks for nylon 66. Starting from 1,3-butadiene or a butadiene-rich C4-section (> 40% by volume) from a naphtha steamcracker in the first stage a mixture of pentenenitriles is obtained through hydrocyanation (using as Catalysis, catalyst Ni0-phosphine [PR3] or phosphite or phosphonite [P(OR)2R]). The mixture contains mainly trans- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chichibabin Pyridine Synthesis
The Chichibabin pyridine synthesis () is a method for synthesizing pyridine rings. The reaction involves the condensation reaction of aldehydes, ketones, α,β-Unsaturated carbonyl compounds, or any combination of the above, with ammonia. It was reported by Aleksei Chichibabin in 1924. Methyl-substituted pyridines, which show widespread uses among multiple fields of applied chemistry, are prepared by this methodology. Representative syntheses : The syntheses are presently conduced commercially in the presence of oxide catalysts such as modified alumina (Al2O3) or silica (SiO2). The reactants are passed over the catalyst at 350-500 °C. 2-Methylpyridine- and 4-Methylpyridine, 4-methylpyridine are produced as a mixture from acetaldehyde and ammonia. 3-Methylpyridine and pyridine are produced from acrolein and ammonia. Acrolein and propionaldehyde react with ammonia affords mainly 3-methylpyridine. 5-Ethyl-2-methylpyridine is produced from paraldehyde and ammonia. Mechanism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picoline
Picoline refers to any of three isomers of methylpyridine (CH3C5H4N). They are all colorless liquids with a characteristic smell similar to that of pyridine. They are miscible with water and most organic solvents. The CAS number of an unspecified picoline isomer is 333-41-1 The methyl group in 2- and 4- picolines is reactive; e.g., 2-picolines condenses with acetaldehyde in the presence of warm aqueous sodium hydroxide to form 2-propenylpyridine. History Picoline was obtained, in impure form, in 1826 by the German chemist Otto Unverdorben (1806 – 1873), who obtained it by the pyrolysis (roasting) of bones. He called it ''Odorin'' due to its unpleasant smell. In 1849, the Scottish chemist Thomas Anderson (1819 – 1874) prepared picoline in pure form, from coal tar and via the pyrolysis of bones. Anderson also named picoline by combining the Latin words ''pix'' (tar) and ''oleum'' (oil) because coal tar oil was a source of picoline. By 1870, the German chemist Adolf von Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridine
Pyridine is a basic 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 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 The molecular electric dipole moment is 2.2 debyes. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niacin (substance)
Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variety of whole and processed foods, with highest contents in fortified packaged foods, meat, poultry, red fish such as tuna and salmon, lesser amounts in nuts, legumes and seeds. Niacin as a dietary supplement is used to treat pellagra, a disease caused by niacin deficiency. Signs and symptoms of pellagra include skin and mouth lesions, anemia, headaches, and tiredness. Many countries mandate its addition to wheat flour or other food grains, thereby reducing the risk of pellagra. The amide derivative nicotinamide (niacinamide) is a component of the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP+). Although niacin and nicotinamide are identical in their vitamin activity, nicotinamide doe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-Cyanopyridine
Nicotinonitrile or 3-cyanopyridine is an organic compound with the formula NCC5H4N. The molecule consists of a pyridine ring with a nitrile group attached to the 3-position. A colorless solid, it is produced by ammoxidation of 3-methylpyridine: :H3CC5H4N + NH3 + 1.5 O2 → NCC5H4N + 3 H2O Nicotinonitrile is a precursor to the vitamin niacin. Nitrilase-catalyzed hydrolysis of 3-cyanopyridine by means of immobilized ''Rhodococcus rhodochrous'' J1 strains leads in quantitative yield to nicotinamide (vitamin B3). The enzyme allows for a more selective synthesis as further hydrolysis of the amide to nicotinic acid is avoided. Oxidation of 3-cyanopyridine with hydrogen peroxide gives 3-cyanopyridine N-oxide, which hydrolyzes to nicotinic acid N-oxide Nicotinic acid ''N''-oxide is an organic compound with the formula (HO2C)C5H4NO. It is the ''N''-oxide of nicotinic acid ((HO2C)C5H4N). It is prepared by oxidation of nicotinic acid or the hydrolysis of 3-cyanopyridine '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorpyrifos
Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems of insects by inhibiting the acetylcholinesterase enzyme. Chlorpyrifos was patented in 1966 by Dow Chemical Company. Chlorpyrifos is considered moderately hazardous to humans (Class II) by the World Health Organization based on acute toxicity information dating to 1999. Exposure surpassing recommended levels has been linked to neurological effects, persistent developmental disorders, and autoimmune disorders. Exposure during pregnancy may harm the mental development of children. In the United Kingdom, the use of chlorpyrifos was banned as of 1 April 2016 (with one minor exception). As of 2020, chlorpyrifos and chlorpyrifos-methyl were banned throughout the European Union, where they may no longer be used. The EU also applied to have ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Vitamins
B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. Though these vitamins share similar names (B1, B2, B3, etc.), they are chemically distinct compounds that often coexist in the same foods. In general, dietary supplements containing all eight are referred to as a vitamin B complex. Individual B vitamin supplements are referred to by the specific number or name of each vitamin, such as B1 for thiamine, B2 for riboflavin, and B3 for niacin. Some are more commonly recognized by name than by number, for example pantothenic acid, biotin, and folate. Each B vitamin is either a cofactor (generally a coenzyme) for key metabolic processes or is a precursor needed to make one and is thus an essential nutrient. List of B vitamins Note: other substances once thought to be vitamins were given numbers in the B-vitamin numbering scheme, but were subsequently discovered to be either not essential for life or manufact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Thieme Verlag
Thieme Medical Publishers is a German medical and science publisher in the Thieme Publishing Group. It produces professional journals, textbooks, atlases, monographs and reference books in both German and English covering a variety of medical specialties, including neurosurgery, orthopaedics, endocrinology, urology, radiology, anatomy, chemistry, otolaryngology, ophthalmology, audiology and speech-language pathology, complementary and alternative medicine. Thieme has more than 1,000 employees and maintains offices in seven cities worldwide, including New York City, Beijing, Delhi, Stuttgart, and three other cities in Germany. History Georg Thieme Verlag was founded in 1886 in Leipzig, Germany, by Georg Thieme when he was 26 years old. Thieme remains privately held and family-owned. The company received some early success in 1896 by publishing Wilhelm Röntgen's famous picture of his wife's hand in what is still one of Thieme's and Germany's oldest journals, the ''Deutsche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springer Science & Business Media
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second largest academic publisher with 65 staff in 1872.Chronology ". Springer Science+Business Media. In 1964, Springer expanded its business internationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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