1305287-24-4Relevant articles and documents
Diverse directions of heterocyclizations involving derivatives of 5-aminopyrazoles and N -arylmaleimides
Rudenko, Roman V.,Komykhov, Sergey A.,Desenko, Sergey M.,Musatov, Vladimir I.,Shishkin, Oleg V.,Konovalova, Irina S.,Vashchenko, Elena V.,Chebanov, Valentin A.
experimental part, p. 783 - 793 (2011/04/16)
Heterocyclization reactions between derivatives of 5-aminopyrazoles and N-arylmaleimides were studied and it was established that several directions are possible. Cyclizations involving 1,3-unsubstituted 5-aminopyrazoles yielded mixtures of two regioisomeric compounds, pyrazolo[1,5-a]pyrimidine-7- carboxamides and pyrazolo[3,4-b]pyridine-4-carboxamides. Reactions of 4-substituted 5-aminopyrazoles in boiling acetic acid or N,N-dimethylformamide in most cases gave pyrazolo[1,5-a]pyrimidine-7-carboxamides as the sole product. The treatment of 1-substituted 5-aminopyrazoles with maleimides possesses high selectivity only in N,N-dimethylformamide yielding pyrazolopyridines while in acetic acid the formation mixtures with pyrrolopyrazolones is observed. The key intermediates of the reaction studied were isolated and discussed. Georg Thieme Verlag Stuttgart New York.