A series of dinitro and monoamino-mononitro analogues of the 5,6-diphenyl-3-alkylaminopyridazines were synthesized and their structure was assigned on the basis of mono and bidimensional NMR experiments. Their inhibitory activity against acyl-CoA:cholesterol acyltransferase (ACAT) was tested on the enzyme prepared from rat liver microsomes. Theoretical studies were performed to correlate the activity of the compounds to their structural features
