4-oxo-azetidin-2-sulfonic-acid-amide and salt of same, preparation and application of same

The invention relates to the novel 4-oxo-azetidine-2-sulfonic acid amides and their salts of the formula I I wherein the radicals have the meanings: R1=hydrogen, halogen; R2=hydrogen, halogen, NH2, C6H5CH2CONH, C6H5OCH2CONH, phthalimido, o-MeNHCOC6H4CONH, isoxazolylcarbonylamino; R3=hydrogen, Me2C=C-COOMe, H2C=C(Me)-CH-COOMe, Me2C=C-COOCH2C6H5, H2C=C(Me)CH-COOCH2C6H4NO2-p, Me2C=C-COOCH2C6H4NO2-p, Me2C=C-COOCH2C6H4Me-m, H2C=C(Me)-CH-COOCH2C6H4Me-m, Me2C=C-COOH; R4=hydrogen or sodium and R5=hydrogen, alkyl, benzyl or heterocycle, i.e. isoxazole or pyrazole etc. The invention also relates to the procedure for the preparation thereof and the use thereof as intermediates in the synthesis of beta-lactam analogs or as active components for the preparations of the drugs for antimicrobial therapy.