title: [Studies on pyridazinone derivatives. XVI. Analgesic-antiinflammatory activities of 3(2H)-pyridazinone derivatives].
abstract: In order to examine analgesic and antiinflammatory activities of the position isomers of 4-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (1, emorfazone), an analgesic-antiinflammatory drug, 5-ethoxy-2-methyl-4-morpholino-3(2H)-pyridazinone (2), 6-ethoxy-2-methyl-4-morpholino-3(2H)-pyridazinone (3) and 6-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (4) were prepared. Since 4 showed the most strong activity among the compounds tested, various 6-alkoxy- or 6-allyloxy-2-alkyl- or 2-cyclohexyl- or 2-phenyl-5-substituted amino-3(2H)-pyridazinones (15, 16) were prepared and examined for their activities. As a result, 4 and 2-methyl-5-morpholino-6-n-propoxy- or 6-n-butoxy-3(2H)-pyridazinone (15b, c) and 6-ethoxy-2-ethyl-5-morpholino-3(2H)-pyridazinone (15 l) were revealed to be more potent in analgesic and antipyretic activities than commercial drugs (1, aminopyrine, mepirizole, tiaramide HCl, phenylbutazone, mefenamic acid). On the basis of the available data, the structure-activity relationship in a series of 6-alkoxy-2-alkyl-5-substituted amino-3(2H)-pyridazinones (15, 16) was also discussed.
authors.affiliation: Hamari Chemical Co., Ltd., Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takaya
authors.forename: M
authors.initials: M
authors.lastname: Sato
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000138:chemical synthesis / Q000494:pharmacology* / Q000633:toxicity; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D011724:Pyridazines / Q000138:chemical synthesis / Q000494:pharmacology* / Q000633:toxicity; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D011724:Pyridazines