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Phosphorus Oxychloride

Other Names:

Phosphoryl chloride

Phosphoryl trichloride

Phosphorus(V) oxide chloride

General Information:


CAS Number: 10025-87-3

Molecular Weight: 153.33 g/mol

Appearance: Colorless liquid

Chemical Formula: POCl3

Melting Point: 1.25 C

Boiling Point: 105.8 C

Density: 1.645 g/mL

Common Uses:

Reagent for the formation of active chloro-heterocycles

Procedure excerpt:

Neat POCl3 (400 mL) was added to the SM (5.0 g, 28.4 mmol) with stirring at 0 C under Ar. After 1 min, the reaction was removed from the ice bath and stirred at RT . . .

[full procedure]

Reagent for the dehydration of unsubstituted amides to nitriles

Procedure excerpt:

A solution of the SM (420 mg, 1.39 mmol) in POCl3 (15 mL) was stirred at 65 C for 2 h. The mixture was cooled to RT and diluted with toluene. The volatiles were . . .

[full procedure]

Reagent in Bischler-Napieralski reactions

Procedure excerpt:

To a solution of the SM (76.0 g, 0.354 mol) in DCM (2.5 L) at 15 C was added POCl3 (155 g, 1.01 mol). After addition, the reaction mixture was heated to reflux . . .

[full procedure]


Phosphorus oxychloride (POCl3) is very toxic and reacts strongly with water.


1) Patent Reference: WO2007117607, page 307, (12.9 MB)

2) Patent Reference: WO2010031852, page 37, (2.8 MB)

3) Patent Reference: WO2016014463, page 94, (6.7 MB)

4) Wikipedia: Phosphoryl chloride (link)

5) Phosphorus(V) oxychloride (link)

6) Pearson, A. J.; Roush, W. R.; Handbook of Reagents for Organic Synthesis; Activating Agents and Protecting Groups