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Parallel synthesis of 7-heteroaryl-pyrazolo[1,5-a]pyrimidine-3-carboxamides

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Abstract

A simple and practical four-step protocol for the parallel synthesis of 7-heteroaryl-pyrazolo[1,5-\(a\)]pyrimidine-3-carboxamides was developed. The synthesis starts with transformation of commercially available 2-acetylpyridine and acetylpyrazine with \(N,\) \(N\)-dimethylformamide dimethylacetal into the corresponding \((E)\)-3-(dimethylamino)-1-(heteroaryl)prop-2-en-1-ones followed by cyclisation with methyl 5-amino-1\(H\)-pyrazole-4-carboxylate to give methyl 7-heteroarylpyrazolo[1,5-\(a\)]pyrimidine-3-carboxylates. Hydrolysis of the ester group and subsequent amidation of the so formed carboxylic acids with 12 primary and secondary aliphatic amines furnished a library of 24 title compounds in good overall yields and purity.

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Acknowledgments

The financial support from Boehringer-Ingelheim Pharma (Biberach, Germany) and from the Slovenian Research Agency through grant P1-0179 is gratefully acknowledged. We also thank EN-FIST Centre of Excellence (Ljubljana, Slovenia) for using SuperNova diffractometer.

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Authors and Affiliations

  1. Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, P.O. Box 537, 1000 , Ljubljana, Slovenia

    Sizana Ahmetaj, Nina Velikanje, Uroš Grošelj, Ines Šterbal, Benjamin Prek, Amalija Golobič, Drago Kočar, Branko Stanovnik & Jurij Svete

  2. Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 , Biberach, Germany

    Georg Dahmann

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  1. Sizana Ahmetaj
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Correspondence to Jurij Svete.

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Ahmetaj, S., Velikanje, N., Grošelj, U. et al. Parallel synthesis of 7-heteroaryl-pyrazolo[1,5-a]pyrimidine-3-carboxamides. Mol Divers 17, 731–743 (2013). https://doi.org/10.1007/s11030-013-9469-3

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