Beiträge zur Chemie von Pyrazolyalkinen

摘要

Palladium-catalyzed reactions of 1-benzoyl-4-iodopyrazole (2a) with monosubstituted acetylenes3a,3band3cin triethylamine solution provide convenient access to the cross-coupled products4a,4band4c. The 4-ethinylpyrazoles5aand7obtained after methanolytic removal of the protecting groups are transformed conveniently into the ketones6aand8by means of Hg(II)-mediated hydratation.