title: [Interesting new rearrangements of the cephalosporin antibiotics].
abstract: On the course of the preparation of new cephalosporin derivatives with potential HLE inhibiting activity, three new rearrangements were observed. When a 7 beta-aminocephem sulfone (prepared in situ from 2) was diazotized in methanolic HClO4 solution with HNO2, the triazole 3 was prepared in good yield. On the other hand, the 2 alpha-bromocephem 6 rearranged to two different products, depending on the solvent used. When it was allowed to stay in acetonitrile for 7 days, the bromopyrrol 8 was the product, while in acetone, THF or DMF the aromatic side chain brominated product 7 was obtained. In both cases the inverse polarity of the C-2-Br bond and the easily resulting bromonium ion can be regarded responsible for the rearrangements.
authors.affiliation: KLTE-MTA Gyógyszerészi Kémiai Tanszék. tamasgunda@tigris.klte.hu
authors.forename: T
authors.initials: T
authors.lastname: Gunda
authors.forename: N S
authors.initials: NS
authors.lastname: Gabriella
authors.forename: L
authors.initials: L
authors.lastname: Tamás
authors.forename: S
authors.initials: S
authors.lastname: Sályi
mesh_terms: D002511:Cephalosporins / Q000138:chemical synthesis / Q000737:chemistry*; D015195:Drug Design; D007202:Indicators and Reagents; D008958:Models, Molecular; D013329:Structure-Activity Relationship
chemical_list: D002511:Cephalosporins; D007202:Indicators and Reagents
vernacular_title: Néhány érdekes új átrendezódés a kefalosporin antibiotikum származékok körében.