2-bromo- and 2-nitroxy derivatives of 3-bromo- and 3,3-dibromo-4-oxo-azetidines, and preparation

Abstract

The azetidines of the present invention have the formula I ##STR1## wherein R.sup.1 is hydrogen or bromine, R.sup.2 is hydrogen or bromine, wherein at least one of R.sup.1 or R.sup.2 is bromine, R.sup.3 is hydrogen; Me.sub.2 --C.dbd.C--COOR.sup.4 wherein R.sup.4 is hydrogen, methyl, benzyl or some other carboxy-protective group, and X is bromine or nitroxy group (--ONO.sub.2). According to the invention 2-bromo- and 2-nitroxy derivatives of 3-bromo- and 3-dibromo-4-oxo-azetidines are prepared by reacting derivatives of protected penicillanic acid 1,1-dioxides with DBN reactant (1,5-diazabicyclo/3.4.0/non-5-ene) and then the obtained DBN salt of sulfinic acid or isolated sulfinic acid is treated with thionyl chloride and, after eliminating thionyl chloride by evaporation, the obtained residue is passed through a silica gel column with methylene chloride or some other solvent as eluant or the obtained residue is dissolved in tetrahydrofuran or some other suitable solvent and treated with tetrabutyl ammonium bromide and after the treatment a derivative of 2-bromo, 3-bromo or 2-bromo-3,3-dibromo-4-oxo-azetidine is isolated, which derivative may be subjected to a reaction with silver nitrate in 2-propanol and, after the treatment of the reaction mixture, derivatives of 2-nitroxy-, 3-bromo- or 2-nitroxy-3,3-dibromo-4-oxo-azetidine are isolated. The obtained substances are useful intermediates in the syntheses of beta lactam analogons or as components in formulations having antibacterial, inhibitory, antitumour or antagonistic action.

Dependencies are inferred from the claim text.