One-pot synthesis of 5-(substituted-amino)pyrazoles
作者:Dharmpal S Dodd、Rogelio L Martinez
DOI:10.1016/j.tetlet.2004.04.017
日期:2004.5
An efficient and mild one-potsynthesis of substituted 5-alkylamino and/or 5-(arylamino)pyrazoles is described. A suitably decorated β-ketoamide, an aryl or alkyl hydrazine and Lawesson's reagent are suspended in THF/Py and gently heated to yield the requisite 5-aminopyrazoles.
[reaction: see text] A fluorous analogue of Lawesson's reagent for thionation of carbonyl compounds has been developed and its use demonstrated on a series of amides, esters, and ketones. The separation of the Lawesson's reagent-derived byproducts can be achieved by a simple fluorous solid-phase extraction.