Issue 48, 2017

Synthesis of 4-substituted pyrazole-3,5-diamines via Suzuki–Miyaura coupling and iron-catalyzed reduction

Abstract

A general and efficient synthesis of 4-substituted-1H-pyrazole-3,5-diamines was developed to access derivatives with an aryl, heteroaryl, or styryl group, which are otherwise relatively difficult to prepare. The first step is based on the Suzuki–Miyaura cross-coupling reaction utilizing the XPhos Pd G2 precatalyst. The coupling reactions of 4-bromo-3,5-dinitro-1H-pyrazole with the electron-rich/deficient or sterically demanding boronic acids enabled the production of the corresponding dinitropyrazoles. The subsequent iron-catalyzed reduction of both nitro groups with hydrazine hydrate accomplished the synthesis. The additional demethylation of the 4-methoxystyryl derivative allowed the production of the carboanalog of CAN508 reported as a selective CDK9 inhibitor.

Graphical abstract: Synthesis of 4-substituted pyrazole-3,5-diamines via Suzuki–Miyaura coupling and iron-catalyzed reduction

Supplementary files

Article information

Article type
Paper
Submitted
22 Sep 2017
Accepted
16 Nov 2017
First published
16 Nov 2017

Org. Biomol. Chem., 2017,15, 10200-10211

Synthesis of 4-substituted pyrazole-3,5-diamines via Suzuki–Miyaura coupling and iron-catalyzed reduction

M. Tomanová, L. Jedinák, J. Košař, L. Kvapil, P. Hradil and P. Cankař, Org. Biomol. Chem., 2017, 15, 10200 DOI: 10.1039/C7OB02373A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements