7 Phosphorus Oxychloride Uses: Facts You Should Know!

Phosphorus Oxychloride is an inorganic colourless liquid having molecular formula POCl3 and molecular weight of 153.32 g·mol−1.Let us see various uses of Phosphorus Oxychloride.

The different uses of Phosphorus Oxychloride molecule in different fields are mentioned below:

  • Chlorinating Agent
  • Fuel Additives and Hydraulic Fluids
  • Semiconductors
  • Laboratory Reagent
  • Manufacturing of Poly  Esters
  • Pesticides
  • Plasticizers

Let us see about each uses under different sub-topics which has the element phosphorus oxychloride in them in detail in this article.

Chlorinating Agent

  • Phosphorus Oxychloride is used for Chlorination of Quinazolones giving chlorinated product called “Chloroquinazolines”. The mixture of Phosphorus Oxychloride (POCl3) and Phosphorus Pentachloride (PCl5) is used from very long time as a strong Chlorinating agent.
  • Long-acting sulfa compounds are chlorinated using POCl3. Organic synthesis of chlorinating agents and catalysts are also done using POCl3.

Fuel Additives and Hydraulic Fluids

  • Phosphorus Oxychloride is used as a gasoline additive as it is effective in altering the engine deposits. The reaction of POCl3 with Polar Polyhydric compound leads to formation of liquid polyester. These polyesters have better lubricating properties than hydrocarbon fluids.
  • Compound called tricresyl phosphate which is manufactured using POCl3 is commercially famous for its uses in gasoline additive, hydrolytic fluids.


  • Phosphorus Oxychloride is used as Phosphorus dopant in semiconductor industries as well as in solar industries and etching solutions.
  • The combination of POCl3 and Hydrofluoric acid solution is used for the fabrication of microchips and other components, which helps them in dissolving silicon oxide layers on a wafer. POCl3 is also used as a raw material in manufacturing of light-conducting fibers and anti-refraction doping source in optical fibers.

Laboratory Reagent

  • Phosphorus Oxychloride is used as a dehydrating agent in laboratories. It dehydrates primary amines into nitriles.
  •  POCl3 is used in preparation of p-Dimethylaminobenzaldehyde which is widely used reagent in identification of amines, indoles, amino acids and peptides, hydrazines and hydrogen peroxides.
  • POCl3 is used as an intermediate in laboratory preparation of dyes and in cryoscopy it is used as a solvent.
  • POCl3 is used in preparation of Vilsmeier’s Reagent and in Bischler-Napieralski reaction. In Uranium mining POCl3 is used as an extracting agent.

Manufacturing of Poly Esters

  • Phosphorus Oxychloride is used in preparation of Simple Trialkyl Phosphate.
  • Esters are also prepared by reaction of alkanols with carboxylic acid by carboxyl activation method in presence of combination mixture of POCl3 and DMAP (4-Dimethylaminopyridine).

What Are the Common Uses of Phosphorus Pentachloride?

Phosphorus pentachloride applications revealed this compound finds common uses in various industries. It is employed as a reagent in organic synthesis, particularly for introducing chlorine atoms into molecules. Additionally, it acts as a catalyst in chemical reactions, as a chlorinating agent, and in the production of pharmaceuticals and pesticides. Its versatility and effectiveness make it an invaluable resource in many chemical processes.


Phosphate esters which are manufactured using Phosphorus Oxychloride is used in Flame retardants and pesticides, a raw material for producing and manufacturing of chlordimeform and organic phosphorus herbicides.


Phosphorus Oxychloride is used in manufacturing of cyclic and acyclic esters which are used in making of plasticizers and plastic additives. It is used in making compound which works as flame retardants in plastics.


POCl3 is a very essential compound in various industries and very useful reagent in many laboratory reactions. Its chlorinating and dehydrating properties are widely used in many industries.