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Updated: Jun 18, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Preparation of 3,4-Substituted-5-Aminopyrazoles and 4-Substituted-2-Aminothiazoles
Stepan Havel1,2, Prashant Khirsariya1,2, Naresh Akavaram1,2
1Department of Chemistry, CZ Openscreen , Masaryk University , Kamenice 5 , 625 00 Brno , Czech Republic.
Abstract:
3,4-Substituted-5-aminopyrazoles and 4-substituted-2-aminothiazoles are frequently used intermediates in medicinal chemistry and drug discovery projects. We report an expedient flexible synthesis of 3,4-substituted-5-aminopyrazoles (35 examples), based on palladium-mediated α-arylation of β-ketonitriles with aryl bromides. A library of 4-substituted-2-aminothiazoles (21 examples) was assembled by a sequence employing Suzuki coupling of newly prepared, properly protected pinacol ester and MIDA ester of 4-boronic acid-2-aminothiazole with (hetero)aryl halides.
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