Synthesis of some pyrrolo[3,4-d]pyridazinones and their preliminary anticancer, antimycobacterial and CNS screening

Starting from 1-substituted-2,5-dimethyl-3,4-pyrroledicarboxylic acid anhydrides 1 and N-methylhydrazine, 1,2,3,4-tetrahydro-6-substituted-2,5,7-trimethyl-6H-pyrrolo[3,4-d]pyridazin-1,4-ones 2 were prepared. Reaction of compounds 2 with alkylating agents give 3-N- or 4-O-alkylated products 3, 4 or mixtures of these isomers in ratios depending on the alkylating agents. Under preliminary pharmacological screening two of four new pyrrolo[3,4-d]pyridazinones were active as cystostatic agents, all the eight compounds displayed moderate activity against Mycobacterium tuberculosis and two compounds were active as CNS-depressive agents.