Synthesis and Biological Evaluation of 2‐substituted‐6‐(morpholinyl/piperidinyl)pyridazin‐3(2H)‐ones as Potent and Safer Anti‐inflammatory and Analgesic Agents

A series of 2-substituted-6-(morpholinyl/piperidinyl)pyridazin-3(2H)-ones was synthesized and the structures were established using various spectroscopic techniques. The target compounds were screened for anti-inflammatory and analgesic activities at 20 and 40mg/kg. The safety of the synthesized derivatives was evaluated by assessing anti-platelet activity and ulcer index. The obtained pharmacological data revealed that 6-morpholinyl derivatives 4a-12a were found to be somewhat more potent than 6-piperidinyl derivatives 4b-6b. The 6-morpholinyl substituted pyridazinone 12a exhibited maximum anti-inflammatory and analgesic activities. Homoveratrylamine substituted compounds 6a and 6b emerged as promising leads in both the series with good anti-inflammatory and analgesic activities without any ulcerogenicity. Anti-platelet activity results of the compounds of both the series showed significantly low bleeding time in comparison with standard drug aspirin indicating the cardiovascular safety of new pyridazinones.