Ethyltriphenylphosphonium bromide
[CAS# 1530-32-1]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Ethyltriphenylphosphonium bromide
• Molecular Formula: C₂₀H₂₀BrP
• Molecular Weight: 371.25
• CAS Registry Number: 1530-32-1
• EC Number: 216-223-3
• SMILES: CC[P+](C1=CC=CC=C1)(C2=CC=CC=C2)C3=CC=CC=C3.[Br-]

Properties

• Melting point: 203-205 °C (Expl.)
• Water solubility: 120 g/L (23 °C)

Safety Data

• Hazard Symbols: GHS05;GHS06;GHS07;GHS08;GHS09 Danger
• Risk Statements: H301-H302-H312-H315-H318-H319-H332-H335-H373-H411-H412
• Safety Statements: P260-P261-P264-P264+P265-P270-P271-P273-P280-P301+P316-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	3	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	4	H332
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	2	H300

• Transport Information: UN 3077

Discovery and Applications

Ethyltriphenylphosphonium bromide (C6H5)3PCH2CH3Br is a quaternary ammonium salt comprising an ethyl group attached to a triphenylphosphonium cation, with a bromide anion. It is synthesized by reacting triphenylphosphine with ethyl bromide, which leads to the formation of this well-characterized phosphonium salt.

Ethyltriphenylphosphonium bromide is widely used in organic synthesis, particularly as a reagent in the Wittig reaction. In this reaction, ethyltriphenylphosphonium bromide reacts with carbonyl compounds, such as aldehydes or ketones, to produce alkenes. The process involves the formation of a phosphonium ylide intermediate, which is crucial in the formation of a carbon-carbon double bond, a key step in the synthesis of various organic molecules. The Wittig reaction, facilitated by ethyltriphenylphosphonium bromide, is essential in the production of alkenes, which are used in the synthesis of numerous chemical products including pharmaceuticals and agrochemicals.

Beyond its role in the Wittig reaction, ethyltriphenylphosphonium bromide is also used in other synthetic applications, particularly in the formation of phosphonium ylides for reactions involving nucleophilic substitution or addition to electrophilic species. Its utility extends to the preparation of other phosphonium salts, which are valuable in a variety of chemical processes.

The compound is also significant in the synthesis of substituted alkylated derivatives and in reactions where phosphonium compounds are required as electrophiles or catalysts. Due to its well-defined structure and reactivity, ethyltriphenylphosphonium bromide plays an important role in organic synthesis and catalysis, making it a versatile and useful reagent in the chemical industry.

In conclusion, ethyltriphenylphosphonium bromide is a valuable chemical reagent in organic chemistry, particularly in the Wittig reaction for the formation of alkenes. Its applications in various synthetic processes highlight its importance as a versatile phosphonium compound in organic synthesis.

References

2025. Recent developments in antimicrobial small molecule quaternary phosphonium compounds (QPCs) - synthesis and biological insights. RSC Medicinal Chemistry.
DOI: 10.1039/D4MD00855C

1980. Effects of phosphonium compounds on Schistosoma mansoni. Journal of Medicinal Chemistry, 23(8).
DOI: 10.1021/jm00182a010

2014. Atom-economic threefold cross-couplings of triarylbismuth reagents with 2-halobenzaldehydes and pot-economic in situ Wittig functionalizations with phosphonium salts. RSC Advances, 4(104).
DOI: 10.1039/C4RA13348J