Download PDF
Synfacts 2009(5): 0486-0486  
DOI: 10.1055/s-0029-1216604
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Pyrazolopyridines

Contributor(s): Victor Snieckus, Toni Rantanen
G. L. Beutner*, J. T. Kuethe, M. M. Kim, N. Yasuda
Merck and Co., Inc., Rahway, USA
Further Information

Publication History

Publication Date:
22 April 2009 (online)

    Permissions and Reprints

Significance

An effective strategy for the preparation of 3-alkoxymethyl-pyrazolo[3,4-b]pyridines has been developed. The method involves the acylation of 2-fluoropyridines with LDA and ­Weinreb amide, followed by a cyclization with ­hydrazine to form the pyrazole ring. Both steps proceed in poor to good yields, but the second step fails for one substrate (R = 3,4-diClC6H3) due to extensive decomposition. The substrate scope was poorly studied, albeit some further modifications of the product (pyrazolopyridines) were shown.