PYRIDAZINO[3,4-B][1,5]BENZODIAZEPIN-5-ONES - SYNTHESIS AND BIOLOGICALEVALUATION

Starting from 3,6-dichloropyridazine-4-carboxylic acid chloride, a ser ies of pyridazino[3,4-b][1,5]benzodiazepin-5-ones bearing various subs tituents in positions 3, 6, 8 and 11 was prepared via (2-choro-5-nitro phenyl)-pyridazine-4-carboxamides. The latter were smoothly accessible by treatment of hloro-N-(2-fluorophenyl)-pyridazine-4-carboxamides wi th primary aliphatic amines. The new tricyclic compounds, which are st ructurally related to nevirapine and congeners were screened as human immunodeficiency virus type 1 reverse transcriptase inhibitors; the in fluence of the substitution pattern on inhibitory potency is discussed .