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

Felicia Phei Lin Lim; Khai Ching Tan; Giuseppe Luna; Edward R.T. Tiekink; Anton V. Dolzhenko

doi:10.1016/j.tet.2019.03.003

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

Felicia Phei Lin Lim, Khai Ching Tan, Giuseppe Luna, Edward R.T. Tiekink, Anton V. Dolzhenko

Malaysia Sch of Pharmacy

Research output: Contribution to journal › Article › Research › peer-review

12 Citations (Scopus)

Abstract

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.

Original language	English
Pages (from-to)	2314-2321
Number of pages	8
Journal	Tetrahedron
Volume	75
Issue number	15
DOIs	https://doi.org/10.1016/j.tet.2019.03.003
Publication status	Published - 12 Apr 2019

Keywords

Decarboxylation
Hydrolysis
Microwave-assisted Synthesis
Pyrazole
Tautomerism

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10.1016/j.tet.2019.03.003

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title = "A new practical synthesis of 3-amino-substituted 5-aminopyrazoles and their tautomerism",

abstract = "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.",

keywords = "Decarboxylation, Hydrolysis, Microwave-assisted Synthesis, Pyrazole, Tautomerism",

author = "Lim, {Felicia Phei Lin} and Tan, {Khai Ching} and Giuseppe Luna and Tiekink, {Edward R.T.} and Dolzhenko, {Anton V.}",

note = "Funding Information: The Research Centre for Crystalline Materials (Sunway University) is thanked for the X-ray intensity data. This work is supported by the Ministry of Higher Education, Malaysia under Fundamental Research Grant Scheme, grant number FRGS/1/2015/SG01/MUSM/03/1. Funding Information: The Research Centre for Crystalline Materials (Sunway University) is thanked for the X-ray intensity data. This work is supported by the Ministry of Higher Education, Malaysia under Fundamental Research Grant Scheme, grant number FRGS/1/2015/SG01/MUSM/03/1 . Publisher Copyright: {\textcopyright} 2019 Elsevier Ltd Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",

year = "2019",

month = apr,

day = "12",

doi = "10.1016/j.tet.2019.03.003",

language = "English",

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T1 - A new practical synthesis of 3-amino-substituted 5-aminopyrazoles and their tautomerism

AU - Lim, Felicia Phei Lin

AU - Tan, Khai Ching

AU - Luna, Giuseppe

AU - Tiekink, Edward R.T.

AU - Dolzhenko, Anton V.

N1 - Funding Information: The Research Centre for Crystalline Materials (Sunway University) is thanked for the X-ray intensity data. This work is supported by the Ministry of Higher Education, Malaysia under Fundamental Research Grant Scheme, grant number FRGS/1/2015/SG01/MUSM/03/1. Funding Information: The Research Centre for Crystalline Materials (Sunway University) is thanked for the X-ray intensity data. This work is supported by the Ministry of Higher Education, Malaysia under Fundamental Research Grant Scheme, grant number FRGS/1/2015/SG01/MUSM/03/1 . Publisher Copyright: © 2019 Elsevier Ltd Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

PY - 2019/4/12

Y1 - 2019/4/12

N2 - 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.

AB - 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.

KW - Decarboxylation

KW - Hydrolysis

KW - Microwave-assisted Synthesis

KW - Pyrazole

KW - Tautomerism

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DO - 10.1016/j.tet.2019.03.003

M3 - Article

AN - SCOPUS:85062724603

SN - 0040-4020

VL - 75

SP - 2314

EP - 2321

JO - Tetrahedron

JF - Tetrahedron

IS - 15

ER -

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

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Synthesis of 5-azapurine derivatives as new modulators of purinergic receptors

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

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Synthesis of 5-azapurine derivatives as new modulators of purinergic receptors

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