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Niementowski Quinoline Synthesis
The Niementowski quinoline synthesis is the chemical reaction of anthranilic acids and ketones (or aldehydes) to form γ-hydroxyquinoline derivatives. Overview In 1894, Niementowski reported that 2-phenyl-4-hydroxyquinoline was formed when anthranilic acid and acetophenone were heated to 120–130 °C. He later found that at higher heat, 200 °C, anthranilic acid and heptaldehyde formed minimal yields of 4-hydroxy-3-pentaquinoline.Hartz, pp. 376–384 Several reviews have been published. Variations The temperatures required for this reaction make it less popular than other quinoline synthetic procedures. However, variations have been proposed to make this a more pragmatic and useful reaction. Adding phosphorus oxychloride to the reaction mixture mediates a condensation to make both isomers of an important precursor to an important α1-adrenoreceptor antagonist. When the 3 position of an arylketone is substituted, it has been shown that a Niementowski-type reaction wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stefan Niementowski
Stefan Niementowski (August 4, 1866 – July 13, 1925 was a Polish chemist. He discovered the Niementowski quinoline synthesis and the Niementowski quinazoline synthesis The Niementowski quinazoline synthesis is the chemical reaction of anthranilic acids with amides to form 4-oxo-3,4-dihydroquinazolines (3''H''-quinazolin-4-ones). Uses Research has demonstrated that the Niementowski quinazoline synthesis could .... He was a president of Polish Copernicus Society of Naturalists (1920–22). References External links Polish Chemistry 1866 births 1925 deaths Polish chemists Lviv Polytechnic rectors {{chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedländer Synthesis
The Friedländer synthesis is a chemical reaction of 2-aminobenzaldehydes with ketones to form quinoline derivatives. It is named after German chemist Paul Friedländer (1857–1923). This reaction has been catalyzed by trifluoroacetic acid, toluenesulfonic acid, iodine, and Lewis acids. Several reviews have been published. Mechanism Two viable reaction mechanisms exist for this reaction. In the first mechanism 2-amino substituted carbonyl compound 1 and carbonyl compound 2 react in a rate-limiting step to aldol adduct 3. This intermediate loses water in an elimination reaction to unsaturated carbonyl compound 4 and then loses water again in imine formation to quinoline 7. In the second mechanism the first step is Schiff base formation to 5 followed by Aldol reaction to 6 and elimination to 7. : The Pfitzinger reaction and the Niementowski quinoline synthesis are variations of the Friedländer reaction. See also * Doebner-Miller reaction *Povarov reaction *Skraup reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensation Reactions
In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a dehydration synthesis. However other molecules can also be lost, such as ammonia, ethanol, acetic acid and hydrogen sulfide. The addition of the two molecules typically proceeds in a step-wise fashion to the addition product, usually in equilibrium, and with loss of a water molecule (hence the name condensation). The reaction may otherwise involve the functional groups of the molecule, and is a versatile class of reactions that can occur in acidic or basic conditions or in the presence of a catalyst. This class of reactions is a vital part of life as it is essential to the formation of peptide bonds between amino acids and to the biosynthesis of fatty acids. Many variations of condensation reactions exist. Common examples include the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pfitzinger Reaction
The Pfitzinger reaction (also known as the Pfitzinger-Borsche reaction) is the chemical reaction of isatin with base and a carbonyl compound to yield substituted quinoline-4-carboxylic acids. Several reviews have been published. Reaction mechanism The reaction of isatin with a base such as potassium hydroxide hydrolyses the amide bond to give the keto-acid 2. This intermediate can be isolated, but is typically not. A ketone (or aldehyde) will react with the aniline to give the imine (3) and the enamine (4). The enamine will cyclize and dehydrate to give the desired quinoline (5). Variations Halberkann variant Reaction of ''N''-acyl isatins with base gives 2- hydroxy-quinoline-4-carboxylic acids. See also *Camps quinoline synthesis *Friedländer synthesis *Niementowski quinazoline synthesis *Talnetant, Cinchocaine Cinchocaine (INN/ BAN) or dibucaine (USAN) is an amide local anesthetic. Among the most potent and toxic of the long-acting local anesthetics, current use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camps Quinoline Synthesis
The Camps quinoline synthesis (also known as the Camps cyclization) is a chemical reaction whereby an o-acylaminoacetophenone is transformed into two different hydroxyquinolines (products A and B) using hydroxide ion. The relative proportions of the hydroxyquinolines (A and B) produced are dependent upon the reaction conditions and structure of the starting material. Although the reaction product is commonly depicted as a quinoline (the enol form), it is believed that the keto form predominates in both the solid state and in solution, making the compound a quinolone. An example of the Camps reaction is given below:''Sequential Cu-Catalyzed Amidation-Base-Mediated Camps Cyclization: A Two-Step Synthesis of 2-Aryl-4-quinolones from o-Halophenones'' Jones, C. P.; Anderson, K. W.; Buchwald, S. L. J. Org. Chem.; (Article); 2007; 72(21); 7968-7973. The amides of 1,3-enaminoketones react to form pyridinones-2 under similar conditions. Camps Reaction and Related Cyclizations. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niementowski Quinazoline Synthesis
The Niementowski quinazoline synthesis is the chemical reaction of anthranilic acids with amides to form 4-oxo-3,4-dihydroquinazolines (3''H''-quinazolin-4-ones). Uses Research has demonstrated that the Niementowski quinazoline synthesis could be employed for the creation of potential EGFR-inhibiting molecules. Hensbergen ''et al''. have shown a synthetic route to a new class of privileged tri- and tetra-cyclic quinazolines containing a medium-sized ring. A nucleophilic aromatic substitution is combined with the Niementowski reaction and a BOP-mediated ring closure to afford several analogues. References # # # # {{cite journal, last1 = Hensbergen, first1 = Albertus Wijnand, last2 = Mills, first2 = Vanessa R., last3 = Collins, first3 = Ian, last4 = Jones, first4 = Alan M., year = 2015, title = An expedient synthesis of oxazepino and oxazocino quinazolines, journal = Tetrahedron Lett. ''Tetrahedron Letters'' is a weekly international journal for rapid publication of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzaldehyde
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful. It is a colorless liquid with a characteristic almond-like odor. The primary component of bitter almond oil, benzaldehyde can be extracted from a number of other natural sources. Synthetic benzaldehyde is the flavoring agent in imitation almond extract, which is used to flavor cakes and other baked goods. History Benzaldehyde was first extracted in 1803 by the French pharmacist Martrès. His experiments focused on elucidating the nature of amygdalin, the poisonous material found in bitter almonds, the fruit of ''Prunus dulcis''. Further work on the oil by Pierre Robiquet and Antoine Boutron-Charlard, two French chemists, produced benzaldehyde. In 1832, Friedrich Wöhler and Justus von Liebig first synthesized benzaldehyde. Production As of 1999, 7000 tonnes of synthetic and 100 tonnes of natural b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedron Letters
''Tetrahedron Letters'' is a weekly international journal for rapid publication of full original research papers in the field of organic chemistry. According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 2.415. Indexing ''Tetrahedron Letters'' is indexed in: References See also *''Tetrahedron In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all the o ...'' *'' Tetrahedron: Asymmetry'' Chemistry journals Weekly journals Publications established in 1959 Elsevier academic journals {{chem-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (chemistry), products, which usually have properties different from the reactants. Reactions often consist of a sequence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinoline
Quinoline is a heterocyclic aromatic organic compound with the chemical formula C9H7N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only slightly soluble in cold water but dissolves readily in hot water and most organic solvents. Quinoline itself has few applications, but many of its derivatives are useful in diverse applications. A prominent example is quinine, an alkaloid found in plants. Over 200 biologically active quinoline and quinazoline alkaloids are identified. 4-Hydroxy-2-alkylquinolines (HAQs) are involved in antibiotic resistance. Occurrence and isolation Quinoline was first extracted from coal tar in 1834 by German chemist Friedlieb Ferdinand Runge; he called quinoline ''leukol'' ("white oil" in Greek). Coal tar remains the principal source of commercial quinoline. In 1842, French chemist Charles Gerhardt obtained a compound by dry distilling quinine, stry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chem
Chem may refer to: * Chemistry practical waali mam *Chemistry *Chemical * ''Chem'' (journal), a scientific journal published by Cell Press *Post apocalyptic slang for "drugs", medicinal or otherwise in the Fallout video game series. In Ancient Egyptian usage: * ''Khem'' (also spelt ''Chem''), the Egyptian word for "black" * Min (god), in the past erroneously named ''Khem'' CHEM may refer to : *A metabolic panel: for instance, CHEM-7, which is the basic metabolic panel *CHEM-DT CHEM-DT is the TVA owned-and-operated television station in Trois-Rivières, Quebec, Canada. It broadcasts a high-definition digital signal on VHF channel 8 from a transmitter on Rue Principale in Notre-Dame-du-Mont-Carmel. Owned by the Grou ..., a Canadian television channel See also * Chemo (other) * Kemi, a place in Finland {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
