作者:Eugene L. Piatnitski Chekler、Hassan M. Elokdah、John Butera
DOI:10.1016/j.tetlet.2008.09.057
日期:2008.11
A convenient one-pot method for the preparation of substituted 2-amino-1,3,4-oxadiazoles has been developed. The method is a significant improvement over previously reported syntheses. Reaction of carboxylic acids with thiosemicarbazides afforded the corresponding oxadiazoles in moderate to good yields. In general, the products precipitated from the reaction mixture, and were collected by filtration. In most of the cases, no chromatographic separations were required. To explore the scope and limitations of this reaction, various aliphatic, aromatic, and heteroaromatic carboxylic acids were reacted with different substituted thiosemicarbazides. The influence of R-1 and R-2 substituents on the reaction yield and additional results demonstrating the versatility of this method are presented. (c) 2008 Elsevier Ltd. All rights reserved.