Methylphosphonic acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.012.370
EC Number
  • 213-607-2
KEGG
MeSH C032627
UNII
  • InChI=1S/CH5O3P/c1-5(2,3)4/h1H3,(H2,2,3,4)
    Key: YACKEPLHDIMKIO-UHFFFAOYSA-N
  • InChI=1/CH5O3P/c1-5(2,3)4/h1H3,(H2,2,3,4)
    Key: YACKEPLHDIMKIO-UHFFFAOYAB
  • CP(=O)(O)O
Properties
CH5O3P
Molar mass 96.02
Appearance White Solid
Melting point 105 to 107 °C (221 to 225 °F; 378 to 380 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Methylphosphonic acid is an organophosphorus compound with the chemical formula CH3P(O)(OH)2. The phosphorus center is tetrahedral and is bonded to a methyl group, two OH groups and an oxygen. Methylphosphonic acid is a white, non-volatile solid that is poorly soluble in organic solvent but soluble in water and common alcohols.[2]

Preparation

Methylphosphonic acid can be prepared from triethylphosphite by first using a Michaelis-Arbuzov reaction to generate the phosphorus(V) centre:[3]

CH3Cl + P(OC2H5)3 → CH3PO(OC2H5)2 + C2H5Cl

The resulting dialkylphosphonate is then treated with chlorotrimethylsilane before hydrolysis of the siloxyphosphonate to generate the desired product.[3]

CH3PO(OC2H5)2 + 2 Me3SiCl → CH3PO(OSiMe3)2 + 2 C2H5Cl
CH3PO(OSiMe3)2 + 2H2O → CH3PO(OH)2 + 2 HOSiMe3

The reaction pathway proceeds via the siloxyphosphonate intermediate due to the difficulty in directly hydrolysing dialkylphosphonates. Katritzky and co-workers published a one-pot synthesis of methylphosphonic acid in 1989.[3]

References

  1. ↑ "Methylphosphonic Acid". Sigma-Aldrich. Retrieved 12 December 2013.
  2. ↑ "methylphosphonic acid - Compound Summary". NCBI. Retrieved 12 December 2013.
  3. 1 2 3 Katritzky, Alan R.; Pilarski, Boguslaw; Johnson, Jack W. (1989). "A One-Pot Procedure For the Preparation of Phosphonic Acids From Alkyl Halides". The New Journal for Organic Synthesis. 22 (2): 209–213. doi:10.1080/00304949009458197.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.