LAUSR

The versatile hitherto reported 3-(1H-indol-3-yl)-1H-pyrazol-5-amine () was synthesized by the reaction of 3-cyanoacetylindole () with hydrazine hydrate in refluxing ethanol and used as a key intermediate for the synthesis of novel pyrazolo[1,5-a]pyrimidines via its reactions with appropriate 1,3-biselectrophilic reagents or through three-component condensations with triethyl orthoformate and compounds possessing an activated methylene group. Besides, the applicability and synthetic potency of () to attain polyfunctionally substituted imidazo[1,2-b]pyrazole, pyrazolo[1,5-a][1,3]diazepine and pyrazolo[1,5-c][1,3,5]thiadiazine derivatives of an expected pharmaceutical interest have been investigated. The mechanistic aspects for the formation of the newly synthesized compounds are discussed.