Pyrophosphoryl chloride
Pyrophosphoryl chloride is the inorganic compound with the formulaP2O3Cl4. Its structure isO(POCl2)2. 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,O(PO(OH)2)2.
The compound is obtained by treating phosphoryl chloride with half an equivalent of methanol, as described in the following chemical equation:
Pyrophosphoryl chloride is proposed as an intermediate in the chlorination of alcohols by phosphoryl chloride. It is also a reagent for Vilsmeier-Haack formylations.