One-Pot Acid-Promoted Synthesis of 6-Aminopyrazolopyrimidines from 1H-Pyrazol-5-yl-N,N-dimethylformamidines or 5-Amino-1H-pyrazole-4-carbaldehydes with Cyanamide

Autor:	Ching-Chun Tseng, Shuo-En Tsai, Sin-Min Li, Fung Fuh Wong
Rok vydání:	2019
Předmět:	Solvent chemistry.chemical_compound chemistry Pyrimidine Organic Chemistry Aromatization Cyanamide Methylene Pyrazole Medicinal chemistry
Zdroj:	The Journal of Organic Chemistry. 84:16157-16170
ISSN:	1520-6904 0022-3263
Popis:	A convenient and efficient one-pot acid-promoted synthesis of 6-aminopyrazolo[3,4-d]pyrimidine has been developed by treatment of 1H-pyrazol-5-yl-N,N-dimethylformamidines or 5-amino-1H-pyrazole-4-carbaldehydes with cyanamide (NH2C≡N) in an acid-mediated solution. This synthetic route involves four steps of deprotection, imination, the key acid-promoted heterocyclization, and aromatization. On the basis of optimized studies, methanesulfonylchloride is considered to be the best solvent. Furthermore, the microwave-assisted synthetic technique was also carried out to improve the major product 6-aminopyrazolo[3,4-d]pyrimidines in this method. Moreover, our proposed mechanism was confirmed in this study, which demonstrates that N-[(5-amino-1,3-diaryl-1H-pyrazol-4-yl)methylene]cyanamide is the intermediate.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::67fb50998130bca478667c02ba126ba3 https://doi.org/10.1021/acs.joc.9b02653 Zobrazit plný text záznamu