In organic chemistry, an aldehyde is an organic compound containing a functional group with the structure R−CH=O. The functional group itself can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many chemicals important in technology and biology.
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.
Pterin is a heterocyclic compound composed of a pteridine ring system, with a "keto group" and an amino group on positions 4 and 2 respectively. It is structurally related to the parent bicyclic heterocycle called pteridine. Pterins, as a group, are compounds related to pterin with additional substituents. Pterin itself is of no biological significance.
Tautomers are structural isomers of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydrogen atom within the compound. The phenomenon of tautomerization is called tautomerism, also called desmotropism. Tautomerism is for example relevant to the behavior of amino acids and nucleic acids, two of the fundamental building blocks of life.
Isoquinoline is an individual chemical specimen - a heterocyclic aromatic organic compound - as well as the name of a family of many thousands of natural plant alkaloids, any one of which might be referred to as "an isoquinoline". It is a structural isomer of quinoline. Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring. In a broader sense, the term isoquinoline is used to make reference to isoquinoline derivatives. 1-Benzylisoquinoline is the structural backbone in many naturally occurring alkaloids such as papaverine. The isoquinoline ring in these natural compound derives from the aromatic amino acid tyrosine.
Tropinone is an alkaloid, famously synthesised in 1917 by Robert Robinson as a synthetic precursor to atropine, a scarce commodity during World War I. Tropinone and the alkaloids cocaine and atropine all share the same tropane core structure. Its corresponding conjugate acid at pH 7.3 major species is known as tropiniumone.
The Fischer oxazole synthesis is a chemical synthesis of an oxazole from a cyanohydrin and an aldehyde in the presence of anhydrous hydrochloric acid. This method was discovered by Emil Fischer in 1896. The cyanohydrin itself is derived from a separate aldehyde. The reactants of the oxazole synthesis itself, the cyanohydrin of an aldehyde and the other aldehyde itself, are usually present in equimolar amounts. Both reactants usually have an aromatic group, which appear at specific positions on the resulting heterocycle.
Aromatization is a chemical reaction in which an aromatic system is formed from a single nonaromatic precursor. Typically aromatization is achieved by dehydrogenation of existing cyclic compounds, illustrated by the conversion of cyclohexane into benzene. Aromatization includes the formation of heterocyclic systems.
Novobiocin, also known as albamycin or cathomycin, is an aminocoumarin antibiotic that is produced by the actinomycete Streptomyces niveus, which has recently been identified as a subjective synonym for S. spheroides a member of the class Actinomycetia. Other aminocoumarin antibiotics include clorobiocin and coumermycin A1. Novobiocin was first reported in the mid-1950s.
The Niementowski quinoline synthesis is the chemical reaction of anthranilic acids and ketones to form γ-hydroxyquinoline derivatives.
The Gabriel–Colman rearrangement is the chemical reaction of a saccharin or phthalimido ester with a strong base, such as an alkoxide, to form substituted isoquinolines. First described in 1900 by chemists Siegmund Gabriel and James Colman, this rearrangement, a ring expansion, is seen to be general if there is an enolizable hydrogen on the group attached to the nitrogen, since it is necessary for the nitrogen to abstract a hydrogen to form the carbanion that will close the ring. As shown in the case of the general example below, X is either CO or SO2.
Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known different compounds, it is one of the largest classes of alkaloids. Many of them possess significant physiological activity and some of them are used in medicine. The amino acid tryptophan is the biochemical precursor of indole alkaloids.
Lead(IV) acetate or lead tetraacetate is an metalorganic compound with chemical formula Pb(C2H3O2)4. It is a colorless solid that is soluble in nonpolar, organic solvents, indicating that it is not a salt. It is degraded by moisture and is typically stored with additional acetic acid. The compound is used in organic synthesis.
Benzotriazole (BTA) is a heterocyclic compound with the chemical formula C6H5N3. Its five-membered ring contains three consecutive nitrogen atoms. This bicyclic compound may be viewed as fused rings of the aromatic compounds benzene and triazole. This white-to-light tan solid has a variety of uses, for instance, as a corrosion inhibitor for copper.
In organic chemistry, a homologation reaction, also known as homologization, is any chemical reaction that converts the reactant into the next member of the homologous series. A homologous series is a group of compounds that differ by a constant unit, generally a methylene group. The reactants undergo a homologation when the number of a repeated structural unit in the molecules is increased. The most common homologation reactions increase the number of methylene units in saturated chain within the molecule. For example, the reaction of aldehydes or ketones with diazomethane or methoxymethylenetriphenylphosphine to give the next homologue in the series.
The Gould–Jacobs reaction is an organic synthesis for the preparation of quinolines and 4‐hydroxyquinoline derivatives. The Gould–Jacobs reaction is a series of reactions. The series of reactions begins with the condensation/substitution of an aniline with alkoxy methylenemalonic ester or acyl malonic ester, producing anilidomethylenemalonic ester. Then through a 6 electron cyclization process, 4-hydroxy-3-carboalkoxyquinoline is formed, which exist mostly in the 4-oxo form. Saponification results in the formation of an acid. This step is followed by decarboxylation to give 4-hydroxyquinoline. The Gould–Jacobs reaction is effective for anilines with electron‐donating groups at the meta‐position.
Ergocryptine is an ergopeptine and one of the ergoline alkaloids. It is isolated from ergot or fermentation broth and it serves as starting material for the production of bromocriptine. Two isomers of ergocryptine exist, α-ergocryptine and β-ergocryptine. The beta differs from the alpha form only in the position of a single methyl group, which is a consequence of the biosynthesis in which the proteinogenic amino acid leucine is replaced by isoleucine. β-Ergocryptine was first identified in 1967 by Albert Hofmann. Ergot from different sources have different ratios of the two isomers.
Furoquinoline alkaloids are a group of alkaloids with simple structure. Distribution of this group of alkaloids is essentially limited to plant family Rutaceae. The simplest member of this group is dictamnine and most widespread member is skimmianine.
Chelidonine is an isolate of Papaveraceae with acetylcholinesterase and butyrylcholinesterase inhibitory activity.
5-Hydroxy-2(5H)-furanone is a furanone derived from oxidation of furfural using singlet oxygen. This oxidation is carried out generally in methanol or ethanol with a sensitizer like methylene blue or Rose bengal. The mechanism of this reaction is depicted as below.
