Synthesis of 8-substituted-6-phenyl-6,7,8,9-tetrahydro-3 H -pyrazolo[4,3- f ]isoquinolines using Pictet-Spengler and Bischler-Napieralski cyclisation methods

Abstract In the following communication we report routes for the synthesis of a set of 8-substituted-6-phenyl-6,7,8,9-tetrahydro-3 H -pyrazolo[4,3- f ]isoquinolines. Pictet-Spengler and Bischler-Napieralski methodologies were employed on the relevant indazole precursors and the merits of the two cyclisation reactions for preparing these structures were assessed.