Process for the preparation of 2-bromo- and 2-nitroxy derivatives of

Abstract

The invention relates to novel 2-bromo- and 2-nitroxy derivatives of 3-,bromo- and 3-dibromo-4-oxo-azetidines, to processes for the preparation thereof and to the use thereof. 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 lanic 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-4oxo-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, anti-tumour or antagonistic action.