Diphenyl chlorophosphate
[CAS 2524-64-3]

Identification

• Classification: Organic raw materials >> Inorganic acid ester
• Name: Diphenyl chlorophosphate
• Synonyms: Diphenyl phosphoryl chloride; Diphenyl phosphorochloridate
• Molecular Formula: C₁₂H₁₀ClO₃P
• Molecular Weight: 268.63
• CAS Registry Number: 2524-64-3
• EC Number: 219-759-6
• SMILES: C1=CC=C(C=C1)OP(=O)(OC2=CC=CC=C2)Cl

Properties

• Density: 1.3±0.1 g/cm³ Calc.^*, 1.297 g/mL (Expl.)
• Boiling point: 363.5±11.0 °C 760 mmHg (Calc.)^*, 369.5 - 371.7 °C (Expl.)
• Flash point: 256.2±26.9 °C (Calc.)^*, 113 °C (Expl.)
• Index of refraction: 1.574 (Calc.)^*, 1.55 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H302-H314-H318-H335
• Safety Statements: P260-P261-P264-P264+P265-P270-P271-P280-P301+P317-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P317-P319-P321-P330-P363-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Skin corrosion	Skin Corr.	1C	H314
Skin corrosion	Skin Corr.	1A	H314

• Transport Information: UN 3265

chemBlink Chemical Story

Diphenyl chlorophosphate, CAS 2524-64-3, is an organophosphorus reagent also known as diphenyl phosphorochloridate or diphenylphosphoryl chloride. NIST and PubChem give the formula C12H10ClO3P. Its phosphorus(V) center carries a phosphoryl group, two phenoxy groups and a reactive chlorine atom, making the P-Cl bond the principal synthetic handle.

Nucleophiles can replace chloride at phosphorus, so diphenyl chlorophosphate is useful for transferring a diphenyl phosphoryl group to oxygen- or nitrogen-containing substrates. Alcohols and amines can therefore be converted into phosphate or phosphoramidate derivatives under suitable conditions. The two phenoxy groups moderate the electrophilic phosphorus center and can also serve as leaving groups in later transformations, making the reagent useful in multistep phosphorus chemistry.

This type of chemistry is important because phosphate-containing structures occur in biological molecules, prodrugs, flame-retardant chemistry and synthetic intermediates. Diphenyl phosphate groups can serve as protected or activated phosphorus functionality: phenyl groups provide an organic-compatible form that can be manipulated before the final phosphorus-containing product is generated.

The same reactivity that makes the reagent useful also demands careful handling. PubChem describes diphenyl chlorophosphate as a colorless to light-yellow liquid with a pungent odor and notes severe irritation hazards. Like many phosphoryl chlorides, it is moisture-sensitive because water can attack the electrophilic phosphorus center and replace chloride.

Diphenyl chlorophosphate is therefore a reagent whose value comes from controlled substitution. The molecule arrives with three different groups around phosphorus already installed; the chemist uses the remaining P-Cl bond as a programmable point of entry. In a synthesis, the chlorine atom is usually temporary, while the phosphoryl framework is the part intended to be transferred or elaborated.

References:
1. PubChem, Diphenyl chlorophosphate, CID 75654, CAS 2524-64-3.
2. NIST Chemistry WebBook, Diphenyl chlorophosphate, CAS 2524-64-3.
3. Corbridge DEC. Phosphorus: Chemistry, Biochemistry and Technology. 6th ed. CRC Press, 2013.

Read more stories