Synthesis 2024; 56(17): 2687-2694
DOI: 10.1055/a-2338-8631
paper

1,3-Dipolar Cycloaddition of Diazophosphonates with Methyl(Ethyl) Acrylate for the Synthesis of 5-Arylpyrazole-3-carboxylates

Nikolay A. Zinovyev
,
Irina P. Beletskaya
,
This work was supported by the grant of the Ministry of Education and Science of the Russian Federation (agreement of 24.04.2024 no. 075-15-2024-547).


Abstract

A wide range of α-aryl-α-diazophosphonates were easily prepared via modified diazo transfer reaction. Benzylphoshonates reacted with tosyl azide (TsN3) in the presence of potassium tert-butoxide (KOtBu) to afford diazophosphonates in yields up to 93% (generally 70–80%). Aryldiazophosponates were successfully explored for the synthesis of 5-aryl-substituted pyrazol-3-carboxylates in one pot by the 1,3-dipolar cycloaddition with alkyl acrylates followed by NaH treatment. The second stage led to elimination of the diethoxylphosphoryl moiety with the aromatization of cycle.

Supporting Information



Publication History

Received: 29 April 2024

Accepted after revision: 05 June 2024

Accepted Manuscript online:
05 June 2024

Article published online:
17 June 2024

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