The Skraup synthesis is a

chemical reaction A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and break ...

used to synthesize

quinoline 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 ...

s. It is named after the Czech chemist

Zdenko Hans Skraup Zdenko Hans Skraup (March 3, 1850 – September 10, 1910) was a Czech- Austrian chemist who discovered the Skraup reaction, the first quinoline synthesis. Life Skraup was born in Prague, where he attended the Oberrealschule from 1860 till 1 ...

(1850-1910). In the archetypal Skraup reaction,

aniline Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile start ...

is heated with sulfuric acid,

glycerol Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids know ...

, and an

oxidizing agent An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...

such as

nitrobenzene Nitrobenzene is an organic compound with the chemical formula C6H5 NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor ...

to yield quinoline. In this example,

serves as both the

solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

and the oxidizing agent. The reaction, which otherwise has a reputation for being violent, is typically conducted in the presence of

ferrous sulfate Iron(II) sulfate ( British English: iron(II) sulphate) or ferrous sulfate denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7) but several values for x are kn ...

Arsenic acid Arsenic acid or trihydrogen arsenate is the chemical compound with the formula . More descriptively written as , this colorless acid is the arsenic analogue of phosphoric acid. Arsenate and phosphate salts behave very similarly. Arsenic acid as ...

may be used instead of nitrobenzene and the former is better since the reaction is less violent.

References

{{DEFAULTSORT:Skraup Reaction Condensation reactions Quinoline forming reactions Name reactions

See also

References