68204-13-7Relevant academic research and scientific papers
Base mediated 1,3-dipolar cycloaddition of α-substituted vinyl phosphonates with diazo compounds for synthesis of 3-pyrazolylphosphonates and 5-pyrazolcarboxylates
Goulioukina, Nataliya S.,Makukhin, Nikolay N.,Shinkarev, Egor D.,Grishin, Yuri K.,Roznyatovsky, Vitaly A.,Beletskaya, Irina P.
, p. 10000 - 10010 (2016/11/06)
5-Aryl-substituted pyrazol-3-ylphosphonates have been conveniently synthesized by 1,3-dipolar cycloaddition of 1-formamidovinylphosphonates and aryldiazomethanes under K2CO3/MeOH conditions at room temperature. These pyrazoles are formed in one pot via spontaneous elimination of formamide. Basic conditions prevent competitive formation of cyclopropylphosphonates. 3-Aryl substituted pyrazol-5-carboxylates can be synthesized by the same methodology from 1-arylvinylphosphonates and ethyl diazoacetate, although a stronger base NaH is necessary to ensure the success of the aromatization stage with the elimination of the diethoxylphosphoryl moiety.
1,3-Dipolar cycloaddition of diazoalkanes onto dimethyl 1-(formylamino)ethylenephosphonate: A new route to 1-aminocyclopropanephosphonic acids and 3-phosphorylated pyrazoles
Goulioukina, Nataliya S.,Makukhin, Nikolay N.,Beletskaya, Irina P.
experimental part, p. 9535 - 9540 (2012/01/02)
Diazoalkanes regiospecifically react with dimethyl 1-(formylamino) ethylenephosphonate (1a) to afford 5-substituted dimethyl 3-(formylamino)-4,5- dihydro-3H-pyrazol-3-phosphonates 2 in high yields. Their thermal decomposition followed by hydrolysis provid
