Aromatic compounds or arenes usually refers to organic compounds "with a chemistry typified by benzene" and "cyclically conjugated." The word "aromatic" originates from the past grouping of molecules based on odor, before their general chemical properties were understood. The current definition of aromatic compounds does not have any relation to their odor. Aromatic compounds are now defined as cyclic compounds satisfying Hückel's Rule. Aromatic compounds have the following general properties:
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins.
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals, are coordination complexes.
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis.
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.
In organic chemistry, an imine is a functional group or organic compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.
Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C3H3N3. They exist in three isomeric forms, 1,3,5-triazines being common.
Quinazoline is an organic compound with the formula C8H6N2. It is an aromatic heterocycle with a bicyclic structure consisting of two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring. It is a light yellow crystalline solid that is soluble in water. Also known as 1,3-diazanaphthalene, quinazoline received its name from being an aza derivative of quinoline. Though the parent quinazoline molecule is rarely mentioned by itself in technical literature, substituted derivatives have been synthesized for medicinal purposes such as antimalarial and anticancer agents. Quinazoline is a planar molecule. It is isomeric with the other diazanaphthalenes of the benzodiazine subgroup: cinnoline, quinoxaline, and phthalazine. Over 200 biologically active quinazoline and quinoline alkaloids are identified.
The Einhorn–Brunner reaction is the designation for the chemical reaction of imides with alkyl hydrazines to form an isomeric mixture of 1,2,4-triazoles. It was initially described by the German chemist Alfred Einhorn in a paper, published in 1905, describing N-methylol compounds of amides. In 1914 chemist Karl Brunner published a paper expanding on Einhorn's research of the reaction pictured below, thus resulting in the naming as the Einhorn-Brunner. Substituted 1,2,4-triazole have been prepared from diverse imides and hydrazines.
A triazole is a heterocyclic compound featuring a five-membered ring of two carbon atoms and three nitrogen atoms with molecular formula C2H3N3. Triazoles exhibit substantial isomerism, depending on the positioning of the nitrogen atoms within the ring.
Ring-closing metathesis (RCM) is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the E- or Z- isomers and volatile ethylene.
p-Cymene is a naturally occurring aromatic organic compound. It is classified as an alkylbenzene related to monocyclic monoterpenes. Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. p-Cymene is insoluble in water, but miscible with organic solvents.
Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis. It occurs in a variety of foodstuffs, e.g. soybean oils.
The Niementowski quinazoline synthesis is the chemical reaction of anthranilic acids with amides to form 4-oxo-3,4-dihydroquinazolines (3H-quinazolin-4-ones).
Etaqualone is a quinazolinone-class GABAergic and is an analogue of methaqualone that was developed in the 1960s and marketed mainly in France and some other European countries. It has sedative, hypnotic, muscle relaxant and central nervous system depressant properties resulting from its agonist activity at the β-subtype of the GABAA receptor, and was used for the treatment of insomnia.
Dipeptidyl peptidase-4 inhibitors are enzyme inhibitors that inhibit the enzyme dipeptidyl peptidase-4 (DPP-4). They are used in the treatment of type 2 diabetes mellitus. Inhibition of the DPP-4 enzyme prolongs and enhances the activity of incretins that play an important role in insulin secretion and blood glucose control regulation. Type 2 diabetes mellitus is a chronic metabolic disease that results from inability of the β-cells in the pancreas to secrete sufficient amounts of insulin to meet the body's needs. Insulin resistance and increased hepatic glucose production can also play a role by increasing the body's demand for insulin. Current treatments, other than insulin supplementation, are sometimes not sufficient to achieve control and may cause undesirable side effects, such as weight gain and hypoglycemia. In recent years, new drugs have been developed, based on continuing research into the mechanism of insulin production and regulation of the metabolism of sugar in the body. The enzyme DPP-4 has been found to play a significant role.
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism refers to the existence or possibility of isomers.
Diazanaphthalenes are a class of aromatic heterocyclic chemical compounds that have the formula C8H6N2. They consist of a naphthalene double ring in which two of the carbon atoms have been replaced with nitrogen atoms. There are ten positional isomers, which differ by the locations of the nitrogen atoms.
Zhao Yufen is a Chinese chemist at the college of chemistry and chemical engineering at Xiamen University. She has been an outspoken critic of chemical plants. She was the youngest female member elected to the Chinese Academy of Sciences.
Quinazoline alkaloids are natural products from the group of alkaloids, which are chemically derived from quinazoline. Some quinazoline alkaloids show bronchodilatory effects and stimulate respiration. An abortive effect was also found for vasicine in studies on rats and rabbits.
2-Quinazolinone
4-Quinazolinone