Synthesis of pyrazolo[4,3-f]thieno[3,2-b]quinoline-10-carbonitrile: a new heterocyclic system exhibiting strong fluorescence

Synthesis of new substituted pyrazolo[4,3-f]thieno[3,2-b]quinoline-10-carbonitriles has been accomplished by the nucleophilic substitution of hydrogen in 5-nitroindazole derivatives. The synthesised compounds revealed fluorescent properties and the characteristics of the compounds were studied using UV absorption and emission spectroscopy.