63558-64-5Relevant academic research and scientific papers
Optimized synthesis of 7-azaindazole by a diels-alder cascade and associated process safety
Bailly, Corinne,Bizet, Vincent,Blanchard, Nicolas,Brach, Nicolas,Gallou, Fabrice,Hoehn, Pascale,Lanz, Marian,Le Fouler, Vincent,Parmentier, Michael
, p. 776 - 786 (2020/06/08)
Although pyrimidines are not among the most reactive partners in intramolecular inverse-electron-demand [4πs + 2πs] reactions with alkynes, they can be activated under mild and practical conditions, leading to fused nitrogen-containing heterocycles. We report an optimized synthesis of a 5-iodo-7-azaindazole by a one-pot Diels-Alder cascade that starts from a pyrimidine substituted at the 2-position by an (alkynyl)hydrazone. The safety of the process and the environmental impact were thoroughly evaluated. Eventually, a selection of cross-coupling reactions of 17 were studied and found to allow the introduction of carbon- and nitrogen-based nucleophiles at the 5-position in good to excellent yields.
