Pyrrole is a heterocyclic, aromatic, organic compound, a five-membered ring with the formula C4H4NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., N-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme.
Alizarin is an organic compound with formula C
14H
8O
4 that has been used throughout history as a red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural dye to be produced synthetically.
The Japp–Klingemann reaction is a chemical reaction used to synthesize hydrazones from β-keto-acids and aryl diazonium salts. The reaction is named after the chemists Francis Robert Japp and Felix Klingemann.
The Bischler–Möhlau indole synthesis, also often referred to as the Bischler indole synthesis, is a chemical reaction that forms a 2-aryl-indole from an α-bromo-acetophenone and excess aniline; it is named after August Bischler and Richard Möhlau .
Friedrich Karl Johannes Thiele was a German chemist and a prominent professor at several universities, including those in Munich and Strasbourg. He developed many laboratory techniques related to isolation of organic compounds. In 1907 he described a device for the accurate determination of melting points, since named Thiele tube after him.
The Reimer–Tiemann reaction is a chemical reaction used for the ortho-formylation of phenols. with the simplest example being the conversion of phenol to salicylaldehyde. The reaction was first reported by Karl Reimer and Ferdinand Tiemann.
The Reissert reaction is a series of chemical reactions that transforms quinoline to quinaldic acid. Quinolines will react with acid chlorides and potassium cyanide to give 1-acyl-2-cyano-1,2-dihydroquinolines, also known as Reissert compounds. Hydrolysis gives the desired quinaldic acid.
1,2,4-Trimethylbenzene, also known as pseudocumene, is an organic compound with the chemical formula C6H3(CH3)3. Classified as an aromatic hydrocarbon, it is a flammable colorless liquid with a strong odor. It is nearly insoluble in water but soluble in organic solvents. It occurs naturally in coal tar and petroleum (about 3%). It is one of the three isomers of trimethylbenzene.
In chemistry, the cyclopentadienyl anion or cyclopentadienide is an aromatic species with a formula of [C
5H
5]−
and abbreviated as Cp−. It is formed by the deprotonation of cyclopentadiene. The cyclopentadienyl anion is a ligand which binds to a metal in organometallic chemistry.
The Wurtz–Fittig reaction is the chemical reaction of an aryl halide, alkyl halides, and sodium metal to give substituted aromatic compounds. Following the work of Charles Adolphe Wurtz on the sodium-induced coupling of alkyl halides, Wilhelm Rudolph Fittig extended the approach to the coupling of an alkyl halide with an aryl halide. This modification of the Wurtz reaction is considered a separate process and is named for both scientists.
Hans Freiherr von Pechmann was a German chemist, renowned for his discovery of diazomethane in 1894. Pechmann condensation and Pechmann pyrazole synthesis. He also first prepared 1,2-diketones, acetonedicarboxylic acid, methylglyoxal and diphenyltriketone; established the symmetrical structure of anthraquinone.
The Willgerodt rearrangement or Willgerodt reaction is an organic reaction converting an aryl alkyl ketone, alkyne, or alkene to the corresponding amide by reaction with ammonium polysulfide, named after Conrad Willgerodt. The formation of the corresponding carboxylic acid is a side reaction resulting from hydrolysis of the amide. When the alkyl group is an aliphatic chain, multiple reactions take place with the amide group always ending up at the terminal end. The net effect is thus migration of the carbonyl group to the end of the chain and oxidation.
The Schotten–Baumann reaction is a method to synthesize amides from amines and acid chlorides:
Roland Heinrich Scholl was a Swiss chemist who taught at various European universities. Among his most notable achievements are the synthesis of coronene, the co-development of the Bally-Scholl synthesis, and various discoveries about polycyclic aromatic hydrocarbons.
1,2,3-Trimethylbenzene is an organic compound with the chemical formula C6H3(CH3)3. Classified as an aromatic hydrocarbon, it is a flammable colorless liquid. It is nearly insoluble in water but soluble in organic solvents.
2,6-Naphthalenedicarboxylic acid is an organic compound with the formula C10H6(CO2H)2. This colorless solid is one of several isomers of naphthalenedicarboxylic acid. It is a precursor to the high performance polyester polyethylene naphthalate (PEN, poly(ethylene-2,6-naphthalene dicarboxylate)). It is also used in the synthesis of some metal-organic frameworks.
Spiropentane is a hydrocarbon with formula C5H8. It is the simplest spiro-connected cycloalkane, a triangulane. It took several years after the discovery in 1887 until the structure of the molecule was determined. According to the nomenclature rules for spiro compounds, the systematic name is spiro[2.2]pentane. However, there can be no constitutive isomeric spiropentanes, hence the name is unique without brackets and numbers.
Alexander Ellinger was a German chemist and pharmacologist.
Acetyl nitrate is the organic compound with the formula CH3C(O)ONO2. It is classified as the mixed anhydride of nitric and acetic acids. It is a colorless explosive liquid that fumes in moist air.
The Pschorr cyclization is a name reaction in organic chemistry, which was named after its discoverer, the German chemist Robert Pschorr (1868-1930). It describes the intramolecular substitution of aromatic compounds via aryldiazonium salts as intermediates and is catalyzed by copper. The reaction is a variant of the Gomberg-Bachmann reaction. The following reaction scheme shows the Pschorr cyclization for the example of phenanthrene:
