American Chemical Society
jo8b02655_si_003.cif (1.75 MB)

Preparation of 3,4-Substituted-5-Aminopyrazoles and 4‑Substituted-2-Aminothiazoles

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posted on 2018-11-21, 00:00 authored by Stepan Havel, Prashant Khirsariya, Naresh Akavaram, Kamil Paruch, Benoit Carbain
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.