One‐Pot Three‐Component Synthesis of Highly Functionalized 2,3‐Dihydro‐1,3‐dioxo‐1H,5H‐pyrazolo[1,2‐a][1,2,4]triazoles |
| |
Authors: | Mehdi Adib,Mohammad Hosein Sayahi,Niusha Mahmoodi,Hamid Reza Bijanzadeh |
| |
Affiliation: | Mehdi Adib,Mohammad Hosein Sayahi,Niusha Mahmoodi,Hamid Reza Bijanzadeh |
| |
Abstract: | The reactive 1 : 1 zwitterionic intermediate formed by the addition of isocyanides to dialkyl acetylenedicarboxylates was trapped with 4‐arylurazoles to produce the highly functionalized pyrazolo[1,2‐a][1,2,4]triazoles 5 in good yields (Table). The structures of the products 5a – h were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR), by EI‐MS, and elemental analysis. A possible mechanism for this reaction is proposed (Scheme). |
| |
Keywords: | Isocyanides Acetylenic esters 4‐Arylurazoles Three‐component reactions 1H,5H‐Pyrazolo[1,2‐a][1,2,4]triazoles Zwitterions |
|
|