title: Synthesis of methoxy-2-quinolones via pummerer-type cyclization of N-aryl-N-methyl-3-(phenylsulfinyl)propionamides.
abstract: The thionium ions 10 generated by Pummerer reaction of N-aryl-N-methyl-3-(phenylsulfinyl)propionamides 4 caused not only an electrophilic cyclization reaction producing 2-quinolones 8, but also the formation of the vinyl sulfides 5 and 6 in favor of the latter reaction. On the other hand, the treatment of the vinyl sulfides 5 and 6 with p-toluenesulfonic acid induced cyclization to afford the 2-quinolones 8 in excellent to moderate yields, depending on the electronic properties of the aromatic ring, thus providing a convenient method for the synthesis of methoxy-2-quinolones.
authors.affiliation: Showa Pharmaceutical University, Machida, Tokyo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Toda
authors.forename: M
authors.initials: M
authors.lastname: Sakagami
authors.forename: Y
authors.initials: Y
authors.lastname: Goan
authors.forename: M
authors.initials: M
authors.lastname: Simakata
authors.forename: T
authors.initials: T
authors.lastname: Saitoh
authors.forename: Y
authors.initials: Y
authors.lastname: Horiguchi
authors.forename: T
authors.initials: T
authors.lastname: Sano
mesh_terms: D000089:Acetic Anhydrides; D000577:Amides / Q000737:chemistry*; D003500:Cyclization; D005463:Fluoroacetates; D015363:Quinolones / Q000138:chemical synthesis* / Q000737:chemistry; D013454:Sulfoxides / Q000737:chemistry*; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D000089:Acetic Anhydrides; D000577:Amides; D005463:Fluoroacetates; D015363:Quinolones; D013454:Sulfoxides; C017958:trifluoroacetic anhydride; D014269:Trifluoroacetic Acid