Microwave-assisted preparation of 4-amino-3-cyano-5-methoxycarbonyl-N-arylpyrazoles as building blocks for the diversity-oriented synthesis of pyrazole-based polycyclic scaffolds

• DOI: 10.1039/c4ob01951b
• Publication Date: 2014-11-04T17:01:16Z
• Authors: Laurent Le Corre; Lotfi Tak-Tak; Arthur Guillard; Guillaume Prestat; Christine Gravier...; Patricia Busca
• Keywords: Pyrazole

The synthesis of 4-amino-3-cyano-N-arylpyrazoles A based on a Thorpe-Ziegler cyclization as the key step has been achieved using microwave activation. Via new diversity-oriented synthetic pathway, these highly functionalized building blocks allowed access to various heteroaromatic scaffolds such pyrazolo-pyridines B, pyrazolo-pyrimidines C and pyrazolo-oxadiazoles D. Interestingly, platforms contain three four reactive sites that could be used for post-functionalization in order further increase molecular diversity.