5,6,7,8-Tetrahydropyrido[4,3-c]pyridazine: A Lead-Oriented Scaffold with Two Diversity Points

Abstract

An approach to the derivatives of 5,6,7,8-tetrahydropyrido[4,3-c]pyridazine, a lead-oriented scaffold with two diversity points, was developed. The method included five steps starting from the readily available 4-piperidone derivatives and allowed for the preparation of the target compounds in 32-35% overall yields. The key step of the sequence included one-pot solvent-free reaction of the corresponding 4-piperidone derivative, glyoxylic acid, and hydrazine.

The Cu(OTf)2 catalysed microwave assisted synthesis of a new scaffold, 7-aryl-7,8-dihydropyrido[4,3-c]pyridazin-5(6H)-one

“…5,6,7 The amide-reduced analogues 5,6,7,8-tetrahydropyrido [4,3-c]pyridazines are only reported in two references. 8,9 The 7,8-dihydropyrido [4,3-c]pyridazin-5(6H)-one scaffold as such is still unknown in the scientific literature, leaving an opportunity towards the synthesis of a new possible privileged scaffold.…”