Phosphorus oxychloride

PROPERTIES

Phosphoryl oxychloride is a colorless or slightly yellow fuming liquid with a pungent odor. It is toxic and corrosive, soluble in several common organic solvents. Reacts violently with water. Incompatible with strong oxidizing agents, alcohols, bases (including amines). Stable under normal conditions of use and storage.

APPLICATIONS

MANUFACTURE OF ESTERS

Phosphoryl oxychloride is used in the manufacture of phosphate esters. The esters are widely used in plasticizers for PVC, non-flammable hydraulic fluids, lube oil additives, pesticides, and flame retardants. Triarylphosphate esters such as triphenyl phosphate and tricresyl phosphate are used as flame retardants and plasticisers for PVC. Meanwhile trialkyl esters such as tributyl phosphate are used as liquid-liquid extraction solvents.

PHARMA

Phosphoryl oxychloride is used in the manufacture of several pharmaceuticals. For example, it is applied in chlorination reaction of long-valid p-aminobezene sulfonamide medicines.

AGROCHEMICALS

Phosphoryl oxychloride is used in the production of organic phosphorus pesticide like herbicides and insecticides. Phosphoryl oxychloride is widely used in producing materials of organic-phosphorus pesticide kill-grass agent (e.g. chlordimeform hydrochloride).

It is an intermediate in the synthesis of chemical warfare nerve gases that are toxic to insects and mammals by inhibition of acetylcholinesterase activity.

ELECTRICAL INDUSTRY
Phosphoryl oxychloride is primarily used as a safe liquid phosphorus source for N-type doping in the fabrication of IC, solar cell and some semiconductor discrete components. The phosphorus acts as a dopant used to create N-type layers on a silicon wafer.

DEHYDRATING AGENT

In the laboratory, phosphorus oxychloride is widely used as a dehydrating agent, for example for the conversion of amides to nitriles. Similarly, certain aryl amides can be cyclised to dihydroisoquinoline derivatives using the Bischler-Napieralski reaction. For example pyridones and pyrimidones can be converted to chloro-derivatives of pyridines and pyrimidines, which are important intermediates in the pharmaceutical industry.

Other uses:

Stuff of forming high-purity phosphoric acid.

Catalyst and chlorinating agent in the synthesis of target molecules.

Solvent in cryoscopy.

Cross-linking agent for starch.

Extraction agent for uranium ore.

Anti-refraction doping source (in optical fiber).