The Synthesis of α-Hydroxy- and α-Chlorophosphonic Acid Derivatives Starting from Benzaldehydes and Phosphorous Acid or Dimethyl Phosphite

Title:The Synthesis of α-Hydroxy- and α-Chlorophosphonic Acid Derivatives Starting from Benzaldehydes and Phosphorous Acid or Dimethyl Phosphite

Volume: 23 Issue: 8

Author(s): Alajos Grün*, István Greiner and György Keglevich*

Affiliation:

• Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest,Hungary

• Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest,Hungary

Keywords: Phosphorous acid, dimethyl phosphite, substituted benzaldehydes, α-chlorophosphonic acid, α -hydroxyphosphonic acid, organophosphorus compounds.

Abstract: The addition of phosphorous acid on the C=O group of substituted benzaldehydes in the presence of hydrochloric acid in water affords a mixture of the corresponding α - chlorophosphonic acid and α-hydroxyphosphonic acid. The selectivity towards the α-chloro derivatives may be increased to 92% by the excess of HCl applying forcing conditions. α- Hydroxyphosphonic acids may be synthesized better in yields of 83-92% by the hydrolysis of the corresponding dimethyl α-hydroxyphosphonates. α-Chlorophosphonic acids may also be obtained in yields of 66-79% from α -hydroxyphosphonic esters by reaction with thionyl chloride followed by hydrolysis. The α -chlorophosphonic acids and esters are useful intermediates for other phosphonic derivatives.

Cite this article as:

Grün Alajos *, Greiner István and Keglevich György *, The Synthesis of α-Hydroxy- and α-Chlorophosphonic Acid Derivatives Starting from Benzaldehydes and Phosphorous Acid or Dimethyl Phosphite , Current Organic Chemistry 2019; 23 (8) . https://dx.doi.org/10.2174/1385272823666190611103102