title: [Studies on the new antiarthritic drug candidate S-2474].
abstract: Various 1,2-isothiazolidine-1,1-dioxide (gamma-sultam) derivatives containing an antioxidant moiety, 2,6-di-tert-butyl-phenol substituent, were prepared. Some compounds that have a lower alkyl group at the 2-position of the gamma-sultam skeleton showed potent inhibitory effects on both cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LO), as well as production of interleukin-1 (IL-1) in in vitro assays. They also proved to be effective in several animal arthritic models without any ulcerogenic activities. Among these compounds, (E)-(5)-(3,5-di-tert-butyl-4-hydroxybenzylidence)-2-ethyl-1,2- isothiazolidine-1,1-dioxide (S-2474) was selected as an antiarthritic drug candidate. The structure-activity relationships examined and some pharmacological evaluations are described. Furthermore, we have developed an efficient and E-selective synthesis of S-2474, in which alpha-methoxy-p-quinone methide is used as a key intermediate. alpha-Methoxy-p-quinone methide was revealed to be equivalent to a p-hydroxy-protected benzaldehyde. It reacts smoothly with alpha-sulfonyl carbanion to give 1,6-addition intermediates, which can be further processed to provide S-2474 directly in the presence of a base. This procedure gives S-2474 as an almost single isomer on the benzylidene double bond in excellent yield and thus is a very practical method adaptable to large-scale synthesis. The detailed mechanistic aspects are studied and discussed.
authors.affiliation: Discovery Research Laboratories, Shionogi & Company, Ltd., 12-4, Sagisu 5-chome, Fukushima-ku, Osaka 553-0002, Japan. masanao.inagaki@shionogi.co.jp
authors.forename: Masanao
authors.initials: M
authors.lastname: Inagaki
mesh_terms: D000818:Animals; D018501:Antirheumatic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003499:Cyclic S-Oxides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D051546:Cyclooxygenase 2; D003864:Depression, Chemical; D015232:Dinoprostone / Q000378:metabolism; D015195:Drug Design; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007975:Leukotriene B4 / Q000378:metabolism; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases; D051381:Rats; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: C409872:((E)-(5)-(3,5-di-tert-butyl-4-hydroxybenzylidene)- 2-ethyl-1,2-isothiazolidine-1,1-dioxide); D018501:Antirheumatic Agents; D003499:Cyclic S-Oxides; D007375:Interleukin-1; D007527:Isoenzymes; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D013844:Thiazoles; D007975:Leukotriene B4; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone