Acylation of Heteroaromatic Amines: Facile and Efficient Synthesis of a New Class of 1,2,3-Triazolo[4,5-b]pyridine and Pyrazolo[4,3-b]pyridine Derivatives

Molecules

Hamada Mohamed Ibrahim¹  Haider Behbehani¹  Saad Makhseed¹ 

[1] ¹Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait ²Chemistry Department, Faculty of Science, Fayoum University, Fayoum, A. R., Egypt

关键词: cyanoacetic acid;    cyanoacetamides;    triazolo[4;    5-b]pyridine;    pyrazolo[4;    3-b]- pyridine;    p-nitrophenylacetic acid;    zeolite;   

DOI  :  10.3390/molecules16053723

来源: mdpi

【 摘 要 】

1,2,3-Triazolo[4,5-b]pyridines and pyrazolo[4,3-b]pyridines can be readily prepared via cyanoacetylation reactions of 5-amino-1,2,3-triazoles 1a,b and 4-amino- pyrazole 2 followed by subsequent cyclization of the formed cyanoacetamides. Reactions of amines 1a,b with a mixture of p-nitrophenylacetic acid and acetic anhydride under microwave irradiation conditions afforded the corresponding amides 15a,b that underwent cyclization to form 1,2,3-triazolo[4,5-b]pyridines 16a,b upon heating in DMF solutions containing sodium acetate. Reactions of 1a,b with active methylene compounds, including 17a-c, in the presence of zeolites as catalyst also afforded 1,2,3-triazolo[4,5-b]pyridine derivatives 20a-f via the intermediacy of triazole derivatives 19 and not 18.

【 授权许可】

CC BY   
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