Search results
Results from the WOW.Com Content Network
Halogenation of benzene where X is the halogen, catalyst represents the catalyst (if needed) and HX represents the protonated base. A few types of aromatic compounds, such as phenol, will react without a catalyst, but for typical benzene derivatives with less reactive substrates, a Lewis acid is required as a catalyst.
Phenol – the simplest of the phenols Chemical structure of salicylic acid, the active metabolite of aspirin Chemical structure of aloe emodin, a diphenol Quercetin, a typical flavonoid, is a polyphenol Tannic acid, a typical polyphenol of indeterminate structure Lignin, is around 25% of the composition of wood This structure is repeated many ...
The following is a list of rock types recognized by geologists.There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type.
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (−O H) bonded directly to an aromatic hydrocarbon group. [1] The simplest is phenol, C 6 H 5 OH. Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the ...
The Sandmeyer reaction can also be used to convert aryl amines to phenols proceeding through the formation of an aryl diazonium salt. In the presence of copper catalyst, such as copper(I) oxide, and an excess of copper(II) nitrate, this reaction takes place readily at room temperature neutral water. [28]
Metamorphic rocks are created by rocks that have been transformed into another kind of rock, usually by some combination of heat, pressure, and chemical alteration. Sedimentary rocks are created by a variety of processes but usually involving deposition, grain by grain, layer by layer, in water or, in the case of terrestrial sediments, on land ...
For example, phenols and anilines react quickly with chlorine and bromine water to give multihalogenated products. Many detailed laboratory procedures are available. [ 5 ] For alkylbenzene derivatives, e.g. toluene , the alkyl positions tend to be halogenated by free radical conditions, whereas ring halogenation is favored in the presence of ...
Igneous rocks are formed directly from magma, which is a mixture of molten rock, dissolved gases, and solid crystals. Sedimentary rock is formed from mineral or organic particles that collect at the Earth's surface and become lithified. Metamorphic rock forms by recrystallization of existing solid rock under conditions of great heat or pressure ...