Phosphorus oxychloride is a colourless liquid with a sharp, very characteristic odour. It is very easily hydrolysed, which is accompanied by the release of fumes, and the products of the hydrolysis are phosphoric acid and hydrogen chloride. The reaction of oxychloride with water is very rapid. Due to the high exothermicity of the process and the release of large amounts of asphyxiating hydrogen chloride, transport and storage should take place in tightly sealed packages, protected from moisture or water ingress.
The strong corrosive properties of phosphorus oxychloride have an influence on the type of packaging in which it should be stored and transported. These packages should be made of the suitable material, preferably a specified quality of steel or Teflon.
It is important to use personal protective equipment when working with phosphorus oxychloride, as it can cause burns in contact with the skin. Product should be protected against temperatures that are too high (due to the high vapour pressure of the substance) and too low (as it begins to freeze below 1°C).
POCl3 is a high purity intermediate/raw material which, thanks to its high reactivity, is an excellent substrate for the synthesis of phosphorus and chlorine compounds, widely used in the chemical and pharmaceutical industries.
Phosphorus oxychloride is produced by the oxidation of phosphorus trichloride, and the production technology used gives a product of high purity, that is, containing very small amounts of phosphorus trichloride. This is the superiority and market advantage of this product, especially when used for the synthesis of substances that must be of high purity. The low elemental sulphur content as well as heavy metals such as arsenic, iron, lead, nickel, chromium, and other metals, are not without significance in this case.
POCl3 is a high purity intermediate/raw material, which due to its high reactivity is an excellent substrate for the synthesis of phosphorus and chlorine compounds, widely used in the chemical and pharmaceutical industries. Its reactivity allows the use of POCl3 for the synthesis of, inter alia, active substances (API - Active Pharmaceutical Ingredient).
Phosphorus oxychloride is most commonly used as:
phosphorus introducing agent to the substrate molecule through the formation of phosphates (phosphorylation);
chlorination reagent, used in substitution reactions of hydroxyl groups with a chlorine atom;
activator in coupling reactions, converting carboxylic or sulfonic / sulfinic acids into their chlorides (more reactive derivatives), conjugated to various nucleophiles (e.g., alcohols to form esters or amines to form amides);
a substrate for the synthesis of catalysts, where it acts as a building block for ligands;
reagent in cyclisation processes, e.g. in the process of isoquinoline synthesis using the Bischler-Napieralski procedure.
The above-described processes are used, inter alia, for the synthesis of drugs based on isoquinoline derivatives (phosphorus oxychloride allows the occurrence of intramolecular aromatic electrophilic substitution, e.g. spasmolytic drugs - drotaverine). The phosphorylation process, for example, leads to the synthesis of B vitamins, and nucleotides are formed in the reaction with nucleosides (e.g., fludarabine phosphate used to treat leukaemia).
