Pharmacological evaluation of some new 1-substituted-4-hydroxy-phthalazines.

In the present study, a series of 1-substituted-4-hydroxyphthalazines were synthesized and characterized by IR, 1H-NMR and Elemental analysis. The compounds were assayed against seizures induced by maximal electroshock (MES) and pentylenetetrazole (scMet). Neurologic deficit was evaluated by the rotarod test. The decrease in the elevated motor activity by introceptive chemical stimuli (amphetamine antagonistic activity) was studied at the dose level of 25 and 50 mg kg(-1) and cardiac activity was also studied. All the compounds exhibited significant anticonvulsant activity. Compounds 4, 12, 13 and 17 were most active of the seriesagainst MES-induced seizures. Compounds 2, 4, 13 and 17 exhibited significant decrease in the elevated motor activity at the dose of 50 mg kg(-1). Remarkable sympathetic blocking activity was observed with 3, 5, 6, 7, 9 and 15 only.