No 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.

5,6,7,8-Tetrahydropyrido[4,3-c]pyridazine: A Lead-Oriented Scaffold with Two Diversity Points. -The five step sequence for the synthesis of the title compounds includes the reaction of 4-piperidone derivative (I) with glyoxylic acid and hydrazine as the key step. -(BORISOV, A. V.; VOLOSHCHUK, V. V.; NECHAYEV, M. A.; GRYGORENKO*, O. O.; Synthesis 45 (2013) 17, 2413-2416, http://dx.doi.org/10.1055/s-0033-1339325 ; Taras Shevchenko Natl. Univ., Kiev 01601, Ukraine; Eng.) -Mais 05-156