Synthesis of 4-substituted pyrazole-3, 5-diamines via Suzuki–Miyaura coupling and iron-catalyzed reduction. Issue 48 (27th November 2017)

• Record Type: Journal Article
• Authors: Tomanová, Monika; Jedinák, Lukáš; Košař, Jan; Kvapil, Lubomír; Hradil, Pavel; Cankař, Petr
• Is Part Of: Organic & biomolecular chemistry. Volume 15:Issue 48(2017)
• Page Start: 10200
• Page End: 10211
• Publication Date: 2017-11-27
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c7ob02373a
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : A general and efficient synthesis of 4-substituted-1 H -pyrazole-3, 5-diamines was developed to access derivatives with an aryl, heteroaryl, or styryl group, which are otherwise relatively difficult to prepare. Abstract : A general and efficient synthesis of 4-substituted-1 H -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-1 H -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.