Abstract: A pharmaceutical compound which comprises reacting the sodium penicillanic acid 1,1-dioxides with chloroiodomethane in the presence of a solvent to produce chloromethylpenicillanate 1,1-dioxides, reacting the chloromethylpenicillanate 1,1-dioxides with a sodium iodide to produce iodomethylpenicillanate 1,1-dioxides, and reacting the iodomethylpenicillanate 1,1-dioxide with sodium methampicillin and is effective in the treatment of bacterial infections in a mammal.

Abstract: The present invention relates to hitherto unknown compounds of the general formula I: ##STR1## in which R.sub.1 stands for a phenyl, 4-hydroxyphenyl, 1,4-cyclohexadienyl or a 3-thienyl group; R.sub.2 represents a primary amino or a carboxy group; R.sub.3 is a hydrogen atom, or a lower alkyl, aryl or aralkyl radical, and A stands for a radical of a .beta.-lactamase inhibitor containing a .beta.-lactam ring as well as a carboxy group, A being connected via the carboxy group.The present invention provides new compounds useful in the treatment of bacterial infections. The new compounds are in particular strongly active against .beta.-lactamase producing bacteria.

Abstract: Beta-lactamase inhibiting compounds of the formula ##STR1## or a pharmaceutically acceptable acid addition or carboxylate salt thereof; where n is zero, 1 or 2; X.sub.3 is H or Br, R.sup.1 is H, the residue of certain carboxy-protecting groups or the residue of an ester group readily hydrolyzable in vivo; one of R.sup.12 and R.sup.13 is H and the other is vinyl, certain aryl, alkylthio, alkylsulfonyl or certain heterocyclyl, aminomethyl, thiocarboxamido or amidino groups; one or R.sup.2 and R.sup.3 is H and the other is as disclosed for the other of R.sup.12 and R.sup.13, or is Cl or CH.sub.2 OH, and R.sup.18 is H or certain acyl groups; intermediates useful in their production, methods for their preparation and use, and pharmaceutical compositions containing them.

Abstract: 6-(1-Acyl-1-hydroxymethyl)penicillanic acid derivatives are useful as antibacterials and/or beta-lactamase inhibitors.

Abstract: This invention provides a penam derivative represented by the formula ##STR1## wherein R is hydrogen or methyl and R.sub.1 is (hexahydro-1H-azepin-1-yl)methyleneamino, 2-phenylacetamido, 2-phenoxyacetamido, 2-amino-2-phenylacetamido, 2-amino-2-(p-hydroxyphenyl)acetamido or 2-(4-ethyl-2,3-dioxo-1-piperazine)carboxamido-2-phenylacetamido, and a salt thereof, and processes for preparing them.