Methyl(triphenyl)phosphonium chloride
[CAS# 57283-72-4]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Methyl(triphenyl)phosphonium chloride
• Synonyms: 1,4,6,7-Tetrachloronaphthalene
• Molecular Formula: C₁₉H₁₈ClP
• Molecular Weight: 312.78
• CAS Registry Number: 57283-72-4
• SMILES: CP(C1=CC=CC=C1)(C2=CC=CC=C2)(C3=CC=CC=C3)Cl

Properties

• Density: 1.6±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.666, Calc.^*
• Boiling Point: 342.1±37.0 ºC (760 mmHg), Calc.^*
• Flash Point: 166.7±23.9 ºC, Calc.^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H317-H319
• Precautionary Statements: P280-P305+351+338

Discovory and Applicatios

Methyl(triphenyl)phosphonium chloride, with the molecular formula C21H19ClP, is a quaternary ammonium salt composed of a phosphonium ion with a methyl group and a triphenyl group attached to the phosphorus atom. It is typically synthesized by reacting methyl iodide with triphenylphosphine in the presence of a suitable base, resulting in the formation of the phosphonium salt. The compound appears as a white to light yellow crystalline solid that is soluble in polar organic solvents such as acetone and methanol.

The discovery and application of methyl(triphenyl)phosphonium chloride can be traced to its use in organic synthesis, particularly in reactions that involve the generation of nucleophiles or in phase transfer catalysis. One of the primary uses of methyl(triphenyl)phosphonium chloride is as a reagent in the Wittig reaction, a method for synthesizing alkenes from carbonyl compounds. In this reaction, the phosphonium salt reacts with a strong base to form a ylide, which then undergoes nucleophilic attack on a carbonyl compound, leading to the formation of a carbon-carbon double bond. This process is crucial in the synthesis of a variety of alkenes, including those with important biological or industrial properties.

The compound is also used in other organic reactions, including those that involve the formation of phosphonium ylides. These ylides are highly reactive intermediates and can be used in various synthetic transformations, including in the formation of alkylated products or as catalysts for certain organic reactions. In addition to its role in organic synthesis, methyl(triphenyl)phosphonium chloride is frequently used in the study of organophosphorus chemistry and catalysis.

Another significant application of methyl(triphenyl)phosphonium chloride is in phase transfer catalysis, where it is used to facilitate the transfer of ions between immiscible phases. This property makes it valuable in reactions where ionic reagents need to be transported from an aqueous phase to an organic phase, or vice versa. The use of such phase transfer catalysts can improve the efficiency and selectivity of reactions by promoting faster and more complete reactions between the reactants in different phases.

In addition to its role in chemical synthesis, methyl(triphenyl)phosphonium chloride is used in the preparation of phosphonium-based ionic liquids. Ionic liquids are salts that are liquid at room temperature and are of increasing interest due to their unique properties, such as low volatility, high thermal stability, and the ability to dissolve a wide range of substances. Methyl(triphenyl)phosphonium chloride serves as a precursor in the synthesis of certain ionic liquids that are utilized in electrochemical applications, catalysis, and solvent extraction.

As with many other organophosphorus compounds, methyl(triphenyl)phosphonium chloride should be handled with care. It can cause irritation to the skin, eyes, and respiratory system upon exposure. Safety precautions, including the use of protective gloves, goggles, and working in a well-ventilated area, are necessary when handling this substance.

In conclusion, methyl(triphenyl)phosphonium chloride is an important chemical reagent with a broad range of applications in organic synthesis, particularly in the Wittig reaction and phase transfer catalysis. Its ability to form highly reactive ylides and facilitate the transfer of ions across immiscible phases makes it valuable in a variety of chemical processes. Furthermore, its use in the preparation of ionic liquids adds to its importance in advanced chemical technologies.

References

2023 Insight into the glycerol extraction from biodiesel using deep eutectic solvents Journal of Molecular Modeling
DOI: 10.1007/s00894-023-05453-3

2018 Extraction of Rare-Earth Elements from Hydrochloric Acid by Carbamoyl Methyl Phosphine Oxides in the Presence of Ionic Liquids Russian Journal of Inorganic Chemistry
DOI: 10.1134/s0036023618030221

2009 Synthesis and catalytic epoxidation potentiality of oxodiperoxo molybdenum(VI) complexes with pyridine-2-carboxaldoxime and pyridine-2-carboxylate: the crystal structure of PMePh3[MoO(O2)2(PyCO)] Transition Metal Chemistry
DOI: 10.1007/s11243-009-9228-6