organic synthesis Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...

the Béchamp reaction is used for producing

arsonic acids Arsonic acids are a subset of organoarsenic compounds defined as oxyacids where a pentavalent arsenic atom is bonded to two hydroxyl groups, a third oxygen atom (this one with a double bond), and an organic substituent. The salts/conjugate base ...

from activated aromatic substrates. The reaction is an

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic ni ...

, using

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 ...

as the electrophile. The reaction proceeds according to this idealized stoichiometry for the preparation of

arsanilic acid Arsanilic acid, also known as aminophenyl arsenic acid or aminophenyl arsonic acid, is an organoarsenic compound, an amino derivative of phenylarsonic acid whose amine group is in the 4-position. A crystalline powder introduced medically in the l ...

: :

Reaction scope

The reaction was first reported in 1863 by

Antoine Béchamp Pierre Jacques Antoine Béchamp (16 October 1816 – 15 April 1908) was a French scientist now best known for breakthroughs in applied organic chemistry and for a bitter rivalry with Louis Pasteur. Béchamp developed the Béchamp reduction ...

. It is very analogous to the

sulfonation Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiometry an ...

of arenes. The Béchamp reaction was employed in the

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

-winning work on organoarsenicals by Paul Erlich. In one commercial application, the Béchamp reaction is reaction is used to produce roxarsone, which exhibits an anticoccidial action and promotes growth in animals.

References

{{Organic reactions Substitution reactions Name reactions

Reaction scope

Further reading

References