Synthesis of 8-substituted-6-phenyl-6, 7, 8, 9-tetrahydro-3H-pyrazolo[4, 3-f]isoquinolines using Pictet-Spengler and Bischler-Napieralski cyclisation methods. Issue 30 (25th July 2018)

• Record Type: Journal Article
• Authors: Davies, Robert D.M.; Pink, Jennifer H.; Scott, James S.; Bailey, Andrew
• Is Part Of: Tetrahedron letters. Volume 59:Issue 30(2018)
• Page Start: 2917
• Page End: 2920
• Publication Date: 2018-07-25
• Subjects: 6, 7, 8, 9-Tetrahydro-3H-pyrazolo[4, 3-f]isoquinoline -- Pictet-Spengler -- Bischler-Napieralski; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2018.06.041
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Pictet-Spengler or Bischler-Napieralski used to construct a tricyclic indazole core. Conditions develop to allow indazoles to undergo these cyclisations. Cis stereochemistry preferred in the case of α-methyl indazole ethanamines. 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.