Reactant involved in the synthesis of: 1.Pyrrole-3-carboxylic acids. 2.N-aryl-N-thiazolyl compounds via the Hantzsch reaction. 3.Disubstituted oxadiazolylindole derivatives with antiinflammatory, analgesic and nitric oxide releasing activity. 4.Anilino-aryl-thiazoles with inhibitory activity toward valosin-containing proteins. 5.Tyrosine kinase erythropoietin inhibitors. 6.E. coli methionine aminopeptidase inhibitors.