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 chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles.
Pyridine is a basic heterocyclic organic compound with the chemical formula C
5H
5N. It is structurally related to benzene, with one methine group (=CH−) 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. 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.
Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants, which is important for the management of depression. They are second-line drugs next to SSRI. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains three rings of atoms. Tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.
In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6H5. Phenyl groups are closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, which may be replaced by some other element or compound to serve as a functional group. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry. Although often depicted with alternating double and single bonds, phenyl groups are chemically aromatic and have equal bond lengths between carbon atoms in the ring.
A reagent is a substance or compound added to a system to cause a chemical reaction, or added to test if a reaction occurs. The terms reactant and reagent are often used interchangeably—however, a reactant is more specifically a substance consumed in the course of a chemical reaction. Solvents, though involved in the reaction mechanism, are usually not called reactants. Similarly, catalysts are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates.
The quinones are a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C(=O)– groups with any necessary rearrangement of double bonds, resulting in "a fully conjugated cyclic dione structure". The archetypical member of the class is 1,4-benzoquinone or cyclohexadienedione, often called simply "quinone". Other important examples are 1,2-benzoquinone (ortho-quinone), 1,4-naphthoquinone and 9,10-anthraquinone.
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace amine-associated receptor 1 (TAAR1) and inhibiting vesicular monoamine transporter 2 (VMAT2) in monoamine neurons. To a lesser extent, it also acts as a neurotransmitter in the human central nervous system. In mammals, phenethylamine is produced from the amino acid L-phenylalanine by the enzyme aromatic L-amino acid decarboxylase via enzymatic decarboxylation. In addition to its presence in mammals, phenethylamine is found in many other organisms and foods, such as chocolate, especially after microbial fermentation.
Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its reactions, it resembles benzene. Compounds analogous to thiophene include furan (C4H4O) selenophene (C4H4Se) and pyrrole (C4H4NH), which each vary by the heteroatom in the ring.
Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder. The drug is also used to treat bedwetting. Imipramine is taken by mouth.
Piperazine is an organic compound that consists of a six-membered ring containing two nitrogen atoms at opposite positions in the ring. Piperazine exists as small alkaline deliquescent crystals with a saline taste.
Trazodone, sold under many brand names, is an antidepressant medication. It is used to treat major depressive disorder, anxiety disorders, and, with other medications, alcohol dependence. It is taken by mouth.
Nefazodone, sold formerly under the brand names Serzone, Dutonin, and Nefadar among others, is an atypical antidepressant which was first marketed by Bristol-Myers Squibb in 1994 but has since largely been discontinued. BMS withdrew it from the market by 2004 due to decreasing sales due to the rare incidence of severe liver damage and the onset of generic competition. The incidence of severe liver damage is approximately 1 in every 250,000 to 300,000 patient-years. Generic versions were introduced in 2003.
Hydrazides in organic chemistry are a class of organic compounds with the formula RNHNH2 where R is acyl (R'CO-), sulfonyl (R'SO2-), or phosphoryl (R'2P(O)-). Unlike hydrazine and alkylhydrazines, hydrazides are nonbasic owing to the inductive influence of the acyl, sulfonyl, or phosphoryl substituent.
2-Imidazoline (Preferred IUPAC name: 4,5-dihydro-1H-imidazole) is one of three isomers of the nitrogen-containing heterocycle imidazoline, with the formula C3H6N2. The 2-imidazolines are the most common imidazolines commercially, as the ring exists in some natural products and some pharmaceuticals. They also have been examined in the context of organic synthesis, coordination chemistry, and homogeneous catalysis.
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective insecticides, although some are extremely toxic to humans, including sarin and VX nerve agents.
Etoperidone, associated with several brand names, is an atypical antidepressant which was developed in the 1970s and either is no longer marketed or was never marketed. It is a phenylpiperazine related to trazodone and nefazodone in chemical structure and is a serotonin antagonist and reuptake inhibitor (SARI) similarly to them.
Substituted phenethylamines are a chemical class of organic compounds that are based upon the phenethylamine structure; the class is composed of all the derivative compounds of phenethylamine which can be formed by replacing, or substituting, one or more hydrogen atoms in the phenethylamine core structure with substituents.
1-Phenylpiperazine is a simple chemical compound featuring a phenyl group bound to a piperazine ring. The suffix ‘-piprazole’ is sometimes used in the names of drugs to indicate they belong to this class.
The Quelet reaction is an organic coupling reaction in which a phenolic ether reacts with an aliphatic aldehyde to generate an α-chloroalkyl derivative. The Quelet reaction is an example of a larger class of reaction, electrophilic aromatic substitution. The reaction is named after its creator R. Quelet, who first reported the reaction in 1932, and is similar to the Blanc chloromethylation process.
Cyclopropanol is an organic compound with the chemical formula C3H6O. It contains a cyclopropyl group with a hydroxyl group attached to it. The compound is highly unstable due to the three-membered ring, and is susceptible to reactions that open the ring. It is highly prone to rearrangement, undergoing structural isomerization to form propanal. This property is useful synthetically: cyclopropanol can be used as a synthon for the homoenolate of propanal. The chemical is also useful as a reagent to introduce a cyclopropyl group into ester, sulfate, and amine linkages. The resulting cyclopropyl-containing compounds have been used in investigations of potential antiviral drugs and of modulators of protein trafficking.
