| 摘要 |
<p>Prepn. of dioxopenicillanic derivs. of formula (I) comprises oxidising cpds. of formulae (II) or (III) with H2O2 in presence of a tungsten of molybdenum catalyst. In the formulae R1 is H, halo, alkoxy or CF3; R2 is -CO2H or protected -CO2H, esp. by an ester gp. Salts of I may also be prepd. if R2 is -CO2H or contains an acid or basic gp. Intermediates of formula (VII) are new (where R3 is H, aryl, or (ar)alkyl; X is halo). - Cpds. (I) are inhibitors of beta-lactamase and/or antihotics and/or intermediates for antihotics and/or beta-lactamases. Oxidn. of the penicillanic acids or their sulphones to sulphoxides is obtd. without destroying the lactam ring.</p> |
