|
Pyridine-N-oxide
Pyridine-''N''-oxide is the heterocyclic compound with the chemical formula, formula C5H5NO. This colourless, hygroscopic solid is the product of the oxidation of pyridine. Its synthesis was first reported by Jakob Meisenheimer, who used peroxybenzoic acid as the oxidant. The compound is used infrequently as an oxidizing reagent in organic synthesis. Structure The structure of pyridine-''N''-oxide is very similar to that of pyridine with respect to the parameters for the ring. The molecule is planar. The N–O distance is 1.34Å. The C–N–C angle is 124°, 7° wider than in pyridine. Synthesis The oxidation of pyridine can be achieved with a number of peroxy acids, including peracetic acid and peroxybenzoic acid. Oxidation can also be effected by a modified Dakin reaction using a urea–hydrogen peroxide complex, and sodium perborate or, using methylrhenium trioxide () as catalyst, with sodium percarbonate. Reactions Pyridine ''N''-oxide is five orders of magnitude less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transition Metal Complexes Of Pyridine-N-oxides
Transition metal complexes of pyridine-N-oxides encompass coordination complexes that contain pyridine-N-oxides as ligands. Particularly common are the octahedral homoleptic complexes of the type where M = Mn(II), Fe(II), Co(II), Ni(II). Many variations of pyridine N-oxide are known, such as the dioxides of 2,2'- and 4,4'-Bipyridine, 2,2'-bipyridine. Complexes derived from the trioxide of terpyridine have been crystallized as well. Structure and bonding Pyridine-N-oxides bind to metals through the oxygen. According to X-ray crystallography, the M-O-N angle is approximately 130° in many of these complexes. As reflected by the pKa of 0.79 for , pyridine N-oxides are weakly basic ligands. Their complexes are generally high spin, hence they are kinetically labile. Applications Zinc pyrithione is a coordination compound, coordination complex of a sulfur-substituted pyridine-N-oxide. This zinc complex has useful Fungistatics, fungistatic and bacteriostatic properties.. Referenc ... [...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] |
Heterocyclic Compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of organic heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of organic heterocyclic chemistry focuses especially on organic unsaturated derivatives, and the preponderance of work and applications involves unstrained organic 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of py ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synlett
''Synlett'' is an international scientific journal for accounts and rapid communications of original contributions of fundamental research in synthetic organic chemistry. The impact factor of this journal is 2.419 (2017). ''Nature'' featured a brief piece by the editor-in-chief of the journal in 2017, Benjamin List Benjamin List (; born 11 January 1968) is a German chemist who is one of the directors of the Max Planck Institute for Coal Research and professor of organic chemistry at the University of Cologne. He co-developed organocatalysis, a method of acc ..., where he discussed the journal's experience with the non-traditional peer review system. References Chemistry journals Thieme academic journals Academic journals established in 1989 {{chem-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Pyrithione
Zinc pyrithione (or pyrithione zinc) is a coordination complex of zinc. It has fungistatic (inhibiting the division of fungal cells) and bacteriostatic (inhibiting bacterial cell division) properties and is used in the treatment of seborrhoeic dermatitis and dandruff. Structure of the compound The pyrithione ligands, which are formally monoanions, are chelated to Zn2+ via oxygen and sulfur centers. In the crystalline state, zinc pyrithione exists as a centrosymmetric dimer (see figure), where each zinc is bonded to two sulfur and three oxygen centers. In solution, however, the dimers dissociate via scission of one Zn-O bond. This compound was first described in the 1930s. Pyrithione is the conjugate base derived from 2-mercaptopyridine-''N''-oxide (CAS# 1121-31-9), a derivative of pyridine-''N''-oxide. Uses Medicine Zinc pyrithione can be used to treat dandruff and seborrhoeic dermatitis. It also has antibacterial properties and is effective against many pathoge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omeprazole
Omeprazole, sold under the brand names Prilosec and Losec, among others, is a medication used in the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger–Ellison syndrome. It is also used to prevent upper gastrointestinal bleeding in people who are at high risk. Omeprazole is a proton-pump inhibitor (PPI) and its effectiveness is similar to that of other PPIs. It can be taken by mouth or by injection into a vein. It is also available in the fixed-dose combination medication omeprazole/sodium bicarbonate as Zegerid and as Konvomep. Common side effects include nausea, vomiting, headaches, abdominal pain, and increased intestinal gas. Serious side effects may include ''Clostridioides difficile'' colitis, an increased risk of pneumonia, an increased risk of bone fractures, and the potential of masking stomach cancer. Whether it is safe for use in pregnancy is unclear. It works by blocking the release of stomach acid. Omeprazole was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pranoprofen
Pranoprofen (INN) is a nonsteroidal anti-inflammatory drug (NSAID) used in ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a .... References Nonsteroidal anti-inflammatory drugs {{Musculoskeletal-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niflumic Acid
Niflumic acid is a drug used for joint and muscular pain. It is categorized as an inhibitor of cyclooxygenase-2. In experimental biology, it has been employed to inhibit chloride channel Chloride channels are a superfamily of poorly understood ion channels specific for chloride. These channels may conduct many different ions, but are named for chloride because its concentration ''in vivo'' is much higher than other anions. Several ...s. It has also been reported to act on GABA-A and NMDA channels and to block T-type calcium channels. References Disubstituted pyridines Anilines Trifluoromethyl compounds Calcium channel blockers GABAA receptor positive allosteric modulators NMDA receptor antagonists Aromatic acids Chloride channel blockers Alpha-Amino acids {{musculoskeletal-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acid
Nicotinic acid, or niacin, is an organic compound and a vitamer of vitamin B3, an essential human nutrient. It is produced by plants and animals from the amino acid tryptophan. Nicotinic acid is also a prescription medication. Amounts far in excess of the recommended dietary intake for vitamin functions will lower blood triglycerides and low density lipoprotein cholesterol (LDL-C), and raise blood high density lipoprotein cholesterol (HDL-C, often referred to as "good" cholesterol). There are two forms: immediate-release and sustained-release nicotinic acid. Initial prescription amounts are 500 mg/day, increased over time until a therapeutic effect is achieved. Immediate-release doses can be as high as 3,000 mg/day; sustained-release as high as 2,000 mg/day. Despite the proven lipid changes, nicotinic acid has not been found useful for decreasing the risk of cardiovascular disease in those already prescribed a statin drug. A 2010 review had concluded that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ''N''-oxide. The compound is a precursor to the popular drugs niflumic acid and pranoprofen Pranoprofen (INN) is a nonsteroidal anti-inflammatory drug (NSAID) used in ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a ....{{Ullmann, doi=10.1002/14356007.a22_399, chapter=Pyridine and Pyridine Derivatives, year=2000, last1=Shimizu, first1=Shinkichi, last2=Watanabe, first2=Nanao, last3=Kataoka, first3=Toshiaki, last4=Shoji, first4=Takayuki, last5=Abe, first5=Nobuyuki, last6=Morishita, first6=Sinji, last7=Ichimura, first7=Hisao, isbn=3527306730 References Amine oxides Pyridinium compounds Carboxylic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pergamon Press
Pergamon Press was an Oxford-based publishing house, founded by Paul Rosbaud and Robert Maxwell, that published scientific and medical books and journals. Originally called Butterworth-Springer, it is now an imprint of Elsevier. History The core company, Butterworth-Springer, started in 1948 to bring the "Springer know-how and techniques of aggressive publishing in science"Joe Haines (1988) ''Maxwell'', Houghton Mifflin, p. 137. to Britain. Paul Rosbaud was the man with the knowledge. When Maxwell acquired the company in 1951, Rosbaud held a one-quarter share. They changed the house name to Pergamon Press, using a logo that was a reproduction of a Greek coin from Pergamon. Maxwell and Rosbaud worked together growing the company until May 1956, when, according to Joe Haines, Rosbaud was sacked. When Pergamon Press started it had only six serials and two books. Initially the company headquarters was in Fitzroy Square in West End of London. In 1959, the company moved into He ... [...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] |
