A new practical synthesis of 3-amino-substituted 5-aminopyrazoles and their tautomerism

TETRAHEDRON

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Article

Lim, Felicia Phei Lin¹  Tan, Khai Ching¹  Luna, Giuseppe²  Tiekink, Edward R., I³  Dolzhenko, Anton, V^1,2 

[1] Monash Univ Malaysia, Sch Pharm, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor Darul, Malaysia

[2] Curtin Univ, Fac Hlth Sci, Sch Pharm & Biomed Sci, Curtin Hlth Innovat Res Inst, GPO Box U1987, Perth, WA 6845, Australia

[3] Sunway Univ, Res Ctr Crystalline Mat, Sch Sci & Technol, Bandar Sunway 47500, Selangor Darul, Malaysia

关键词: Pyrazole;    Hydrolysis;    Decarboxylation;    Microwave-assisted Synthesis;    Tautomerism;   

DOI  :  10.1016/j.tet.2019.03.003

来源: Elsevier

【 摘 要 】

It was found that 3-amino-substituted 5-aminopyrazoles could be effectively prepared via hydrolytic decarboxylation of the corresponding 3,5-diaminopyrazole-4-carboxylates under microwave irradiation. The reactions required short time (4 min) and were successfully reproduced in a larger scale and under conventional heating mimicking the microwave heating pattern. X-ray crystallography identified two different types of tautomers in crystals of related 5-aminopyrazoles with p-toluidyl and p-anisidyl moieties at the position 3, respectively. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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