In organic chemistry, a ketene is an organic compound of the form RR'C=C=O, where R and R' are two arbitrary monovalent chemical groups. The name may also refer to the specific compound ethenone H2C=C=O, the simplest ketene.
Phthalic anhydride is the organic compound with the formula C6H4(CO)2O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This white solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the worldwide production volume was estimated to be about 3 million tonnes per year.
In organic chemistry, an imide is a functional group consisting of two acyl groups bound to nitrogen. The compounds are structurally related to acid anhydrides, although imides are more resistant to hydrolysis. In terms of commercial applications, imides are best known as components of high-strength polymers, called polyimides. Inorganic imides are also known as solid state or gaseous compounds, and the imido group (=NH) can also act as a ligand.
An organic acid anhydride is an acid anhydride that is also an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))2O. Symmetrical acid anhydrides of this type are named by replacing the word acid in the name of the parent carboxylic acid by the word anhydride. Thus, (CH3CO)2O is called acetic anhydride.Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see below), are known, whereby reaction occurs between two different carboxylic acids. Nomenclature of unsymmetrical acid anhydrides list the names of both of the reacted carboxylic acids before the word "anhydride" (for example, the dehydration reaction between benzoic acid and propanoic acid would yield "benzoic propanoic anhydride").
Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a dark yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.
Maleic acid or cis-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO2CCH=CHCO2H. Maleic acid is the cis isomer of butenedioic acid, whereas fumaric acid is the trans isomer. Maleic acid is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride, which has many applications.
Carbon suboxide, or tricarbon dioxide, is an organic, oxygen-containing chemical compound with formula C3O2 and structure O=C=C=C=O. Its four cumulative double bonds make it a cumulene. It is one of the stable members of the series of linear oxocarbons O=Cn=O, which also includes carbon dioxide and pentacarbon dioxide. Although if carefully purified it can exist at room temperature in the dark without decomposing, it will polymerize under certain conditions.
Maleic anhydride is an organic compound with the formula C2H2(CO)2O. It is the acid anhydride of maleic acid. It is a colorless or white solid with an acrid odor. It is produced industrially on a large scale for applications in coatings and polymers.
The Robinson–Gabriel synthesis is an organic reaction in which a 2-acylamino-ketone reacts intramolecularly followed by a dehydration to give an oxazole. A cyclodehydrating agent is needed to catalyze the reaction It is named after Sir Robert Robinson and Siegmund Gabriel who described the reaction in 1909 and 1910, respectively.
Succinic anhydride, is an organic compound with the molecular formula (CH2CO)2O. This colorless solid is the acid anhydride of succinic acid.
The Wagner-Jauregg reaction is a classic organic reaction in organic chemistry, named after Theodor Wagner-Jauregg, describing the double Diels–Alder reaction of 2 equivalents of maleic anhydride with a 1,1-diarylethylene. After aromatization of the bis-adduct, the ultimate reaction product is a naphthalene compound with one phenyl substituent.
The Erlenmeyer–Plöchl azlactone and amino acid synthesis, named after Friedrich Gustav Carl Emil Erlenmeyer who partly discovered the reaction, is a series of chemical reactions which transform an N-acyl glycine to various other amino acids via an oxazolone.
Phthalonitrile is an organic compound with the formula C6H4(CN)2, which is an off-white crystal solid at room temperature. It is a derivative of benzene, containing two adjacent nitrile groups. The compound has low solubility in water but is soluble in common organic solvents. The compound is used as a precursor to phthalocyanine and other pigments, fluorescent brighteners, and photographic sensitizers.
Ethylenetetracarboxylic dianhydride is a chemical compound with formula C
6O
6, that can be seen as the twofold anhydride of ethylenetetracarboxylic acid C
6H
4O
8. It has a bicyclic molecular structure consisting of two maleic anhydride rings fused by their respective alkene units. It is a pale yellow oily liquid, soluble in dichloromethane and chloroform.
Citraconic acid is an organic compound with the formula CH3C2H(CO2H)2. It is a white solid. The alkene is cis. The related trans alkene is called mesaconic acid. It is one of the pyrocitric acids formed upon the heating of citric acid. Citraconic acid can be produced, albeit inefficiently, by oxidation of xylene and methylbutanols. The acid displays the unusual property of spontaneously forming the anhydride, which, unlike maleic anhydride, is a liquid at room temperature.
In chemistry, 3,3,4,4-tetramethyltetrahydrofuran-2,5-dione is a heterocyclic compound with the formula C
8H
12O
3, or (CH3)2(COC2COO)(CH3)2. It is a white crystalline solid with a pungent camphoraceous odor.
Shiina macrolactonization is an organic chemical reaction that synthesizes cyclic compounds by using aromatic carboxylic acid anhydrides as dehydration condensation agents. In 1994, Prof. Isamu Shiina reported an acidic cyclization method using Lewis acid catalyst, and, in 2002, a basic cyclization using nucleophilic catalyst.
Shiina esterification is an organic chemical reaction that synthesizes carboxylic esters from nearly equal amounts of carboxylic acids and alcohols by using aromatic carboxylic acid anhydrides as dehydration condensation agents. In 1994, Prof. Isamu Shiina reported an acidic coupling method using Lewis acid, and, in 2002, a basic esterification using nucleophilic catalyst.
Alkenyl succinic anhydrides (ASA) are derivatives of succinic anhydrides. One H of the succinic anhydride ring is replaced with an iso-alkenyl chain (C14 to C22). ASA's are colorless and usually viscous liquids. They are widely used, especially in surface sizing of paper, paperboard, and cardboard, as well as in the hydrophobicization of cellulose fibers. Products treated with it show reduced penetration of aqueous media, such as inks or drinks (like milk or fruit juices).
α,β-Unsaturated carbonyl compounds are organic compounds with the general structure (O=CR)−Cα=Cβ−R. Such compounds include enones and enals, but also carboxylic acids and the corresponding esters and amides. In these compounds, the carbonyl group is conjugated with an alkene. Unlike the case for carbonyls without a flanking alkene group, α,β-unsaturated carbonyl compounds are susceptible to attack by nucleophiles at the β-carbon. This pattern of reactivity is called vinylogous. Examples of unsaturated carbonyls are acrolein (propenal), mesityl oxide, acrylic acid, and maleic acid. Unsaturated carbonyls can be prepared in the laboratory in an aldol reaction and in the Perkin reaction.
