Pyrophosphoryl chloride is the

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula . Its structure is . It is a colorless syrup. In terms of its chemical structure, the compound consists of two tetrahedral phosphorus sites that share an oxo bridge. The name implies that the compound is a derivative of

pyrophosphoric acid Pyrophosphoric acid, also known as diphosphoric acid, is the inorganic compound with the formula H4P2O7 or, more descriptively, HO)2P(O)sub>2O. Colorless and odorless, it is soluble in water, diethyl ether, and ethyl alcohol. The anhydrous aci ...

, . The compound is obtained by treating

phosphoryl chloride Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosp ...

with half an equivalent of

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

, as described in the following chemical equation: : Pyrophosphoryl chloride is proposed as an intermediate in the chlorination of

alcohols In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol ...

by phosphoryl chloride. It is also a reagent for Vilsmeier-Haack formylations.{{cite journal , doi=10.1016/s0040-4020(01)89915-4 , date=1993 , volume=49 , issue=19 , last1=Downie , first1=Ian M. , last2=Earle , first2=Martyn J. , last3=Heaney , first3=Harry , last4=Shuhaibar , first4=Khamis F. , title=Vilsmeier formylation and glyoxylation reactions of nucleophilic aromatic compounds using pyrophosphoryl chloride , journal=Tetrahedron

References

Dehydrating agents Oxychlorides Phosphorus oxohalides Phosphorus(V) compounds