Abstract: The present invention relates to a process for preparing sodium salt of cephalosporins from their corresponding hydrohalide salt, which is neutralized with trimethylsilylating agent for the first time.

Abstract: Process for preparing ceftiofur having formula I: in the form of the sodium salt.

Abstract: A compound of the formula: wherein R1 is amino or protected amino; R2 is hydrogen, lower alkyl or hydroxy protective group; R3 is carboxy or protected carboxy; R4 is an unsubstituted 5, 6 or 7-membered heteromonocyclic group containing two nitrogen atoms as heteroatoms, and which optionally further contains one oxygen or sulfur atom; or R4 is said 5, 6 or 7-membered heteromonocyclic group substituted by 1 to 4 groups selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkylamino, cyclo(lower)alkyl, cyclo(lower)alkenyl, halogen, amino, protected amino, protected hydroxy, cyano, nitro, carboxy, hydroxy(lower)alkyl, amino(lower)alkyl, and carbamoyloxy; and n is 1 or 2.

Abstract: A novel process for the preparation of ceftiofur, a cephalosporin antibiotic useful in the treatment of bovine respiratory disease using a novel bromo or chloro intermediate. the process comprises of the steps of cyclizing a new bromo or chloro intermediate with thiourea in the presence of selected solvents to produce ceftiofur of high purity. A process to prepare such novel bromo and chloro intermediate comprising of the steps of condensing silylated Furaca with 4-(bromo or chloro)-2 methoxyamino-3-oxobutyric acid or its acid halide is also described.

Abstract: A crystalline substance of Cefditoren pivoxyl is provided which has a high purity and enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving an amorphous form of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous form well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg/ml to 250 mg/ml of Cefditoren pivoxyl dissolved in the alkanol alone. From the latter solution, crystals of Cefditoren pivoxyl are induced to deposit by addition of water at a temperature of 0-10° C.

Abstract: Processes for preparing compounds having two or three antibiotic functionalities using quinolone derivatives, &bgr;-lactams and vancomycin and the like as the starting materials and chloride linking agents; and the novel compounds prepared by these processes, are disclosed.

Abstract: A novel cephem compound of the formula: wherein R1 is a phosphono group or a group convertible to a phosphono group; R2 is a hydrogen atom or a group having a linkage through a carbon atom; each of Q and X is a nitrogen atom or CH; Y is S, O or CH2; n is 0 or 1; one of R3 and R4 is a pyridinium group which may be substituted and the other is a hydrogen atom or hydrocarbon group which may be substituted, or R3 and R4 taken together may form a quaternalized nitrogen-containing heterocyclic ring which may be substituted, or its ester or its salt, which has a superior anti-bacterial activity, stability, absorbability, etc., a production thereof and a pharmaceutical composition containing it, is provided.

Abstract: Process for preparing ceftiofur having formula 1: 1

Abstract: The present invention provides novel thioester derivatives of thiazolyl acetic acid of the general formula (I), wherein, R1 represents H, trityl, CH3, or CRaRbCOOR3, in which Ra and Rb, independently of one another, represents hydrogen or methyl and R3 represents H or C1-C7 alkyl; and R2 represents C1-C4 alkyl or phenyl.

Abstract: The present invention provides new thioester derivatives of 4-halogeno-2-methoxyimino-3-oxo-butyric acid of the general formula (I), also, the invention provides a method by which the said thioester derivatives can be prepared by reacting 4-halogeno-2-methoxyimino-3-oxo-butyric acid of the general formula (II) with 2-mercapto-5-substituted-1,3,4-oxadiazoles of the general formula (III) in a solvent, in the presence of DMF/POCl3 and in presence of an organic base and if desired the so obtained thioester derivatives so obtained are reacted with 7-amino-cephem carboxylic acids of the general formula (V) to produce condensed products which are insitu reacted with thiourea to get cephalosporin antibiotic compounds having the general formula (VI).

Abstract: A crystalline substance of Cefditoren pivoxyl is provided which has a high purity and enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving an amorphous form of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous form well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg/ml to 250 mg/ml of Cefditoren pivoxyl dissolved in the alkanol alone. From the latter solution, crystals of Cefditoren pivoxyl are induced to deposit by addition of water at a temperature of 0-10° C.

Abstract: A novel crystal of 7&bgr;-[2-(2-aminothiazol-4-yl)-2-(Z)-(hydroxyimino)acetamido]-3-[pyrazol-4-yl)methylthio]3-cephem-4-carboxylic acid or a salt thereof.

Abstract: Derivatives of 7-alkylidene cephalosporanic acid sulfone and the pharmaceutically active salts thereof are found to be potent inhibitors of &bgr;-lactamase enzymes.

Abstract: The present invention relates to cephalosporin derivatives of the general formula where R1 is halogen, lower alkyl, phenyl, benzyl, styryl, naphthyl or heterocyclyl; the lower alkyl, phenyl, benzyl, styryl, naphthyl and heterocyclyl being optionally substituted by at least one of halogen, hydroxy, optionally substituted lower alkyl, optionally substituted lower alkoxy, optionally substituted phenyl, amino, lower alkylamino, di-lower alkylamino, carboxy, lower alkylcarboxy, carbamoyl or lower alkylcarbamoyl; R4, R5 independently are hydrogen, lower alkyl or phenyl; X is S, O, NH or CH2; n is 0,1 or 2; m is 0 or 1; s is 0 or 1; R2 is hydrogen, hydroxy, —CH2—CONHR6, lower alkyl-Qr, cycloalkyl-Qr, lower alkoxy, lower alkenyl, cycloalkenyl-Qr, lower alkynyl, aralkyl-Qr, aryl-Qr, aryloxy, aralkoxy, a heterocyclic ring or a heterocyclyl-Qr, the lower alkyl, cycloalkyl, lower alkoxy, lower alkenyl, cycloalkenyl, lower alkynyl, aralkyl, aryl, aryloxy, aralkoxy and the heterocyclic

Abstract: As a novel substance is provided such a new, crystalline substance of Cefditoren povoxyl which has a high purity and an enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving amorphous substance of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous substance well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg/ml to 250 mg/ml of Cefditoren pivoxyl dissolved in the alkanol alone.

Abstract: An antibacterial compound wherein represents benzene ring, pyridine ring, pyrazine ring or 5-membered aromatic neterocycle (having one oxygen or sulfur atom as ring-constituting atom), there being no R4 where  represents 5-membered aromatic heterocycle; X and Y respectively represent hydrogen atom or CXY represents C═N—OR5 wherein R5 represents hydrogen atom, halo C1-C6 alkyl or C3-C7 cycloalkyl; R1 represents phenyl, furyl, thienyl, thiazolyl (which may be substituted by amino group), tetrazolyl or thiadiazolyl, R2, R3 and R4 respectively represent hydrogen atom, halogen, hydroxyl group, nitro, C1-C6 alkoxy, trifluoromethyl, isothiuronium C1-C6 alkyl, amino C1-C6 alkyl, halo C1-C6 alkyl, morpholino, piperidino or piperazinyl.

Abstract: There can be produced, at a high selectivity and in a high yield, the Z-isomer of a 7-N-unsubstituted or substituted-amino-3-[2-(4-substituted or unsubstituted-thiazol-5-yl) vinyl]-3-cephem-4-carboxylic acid or an ester thereof having the general formula (IV) wherein R1 denotes a hydrogen atom, a mono-valent amino-protecting group or a 2-(2-N-protected or unprotected aminothiazol-4-yl)- 2-alkoxyiminoacetyl group, R2 denotes a hydrogen atom, or R1 and R2 as taken together mean one di-valent amino-protecting group, R3 denotes a hydrogen atom, pivaloyloxymethyl group or a carboxyl-protecting group and R8 denotes an alkyl group and so on, by a process comprising reacting a 7-N-unsubstituted or substituted-amino-3-[(tri-substituted-phosphoranylidene) methyl]-3-cephem-4-carboxylic acid or an ester thereof having the general formula (I) wherein R1, R2 and R3 each have the same meanings as defined above, and R4 denotes a lower alryl group or an aryl group, with

Abstract: The present invention relates to cephem-derivatives and to a process for their preparation, having proper substituents at C-2 position, i.e. heterocyclylthio or acyloxy group. They are potent protease inhibitors, in particular human leucocyte elastase (HLE) inhibitors.

Abstract: A novel crystal of 7&bgr;-[2-(2-aminothiazol-4-yl)-2-(Z)-(hydroxyimino)acetamido]-3-[pyrazol-4-yl)methylthio]3-cephem-4-carboxylic acid or a salt thereof.

Abstract: A compound represented by the following formula (I) is disclosed. This compound has potent antimicrobial activity against a wide spectrum of bacteria from Gram-positive bacteria to Grame-negative bacteria including &bgr;-lactamase producing bacteria. In particular, it has higher antimicrobial activity against methicilline-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), and imipenem-resistant Pseudomonas aeruginosa than the existing onium salt type cephem derivatives and hence is very useful as a therapeutic agent for infectious diseases derived from various pathogenic bacteria. wherein X represents CH or N, R1 represents a hydrogen atom, substituted or unsubstituted C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, or cycloalkyl; any one of R2, R3, R4, and R5 represents R6R7NSO2NH—C1-6 alkyl where R6 and R7, which may be the same or different, represent a hydrogen atom or C1-6 alkyl; and n is 0 or 1.

Abstract: The invention relates to a new economical and simple process, using a new intermediate compound, for the production of 3′-substituted 7-amino-3-propenyl-4-cephem-carboxylic acid derivatives of formula wherein R is hydrogen, a negative charge or a silyl protecting group, Ro is hydrogen or methoxy, R1 is hydrogen or a silyl protecting group and X is the radical of a nucleophile, and their acid addition salts.

Abstract: A compound of the formula: ##STR1## wherein R.sup.1 is amino or protected amino,R.sup.2 is hydrogen or hydroxy protective group,R.sup.3 is carboxy or protected carboxy,R.sup.4 is hydrogen, lower alkenyl, acyloxy(lower)alkenyl, optionally substituted heterocyclic(lower)alkenyl, optionally substituted heterocyclic(lower)alkenylthio, optionally substituted heterocyclic(lower)alkylthio, or optionally substituted heterocyclic-thio(lower)alkylthio andR5 is halogen or lower alkyland pharmaceutically acceptable salts thereof, which is useful as a medicament for prophylactic and therapeutic treatment of infectious diseases.

Abstract: This invention relates to new cephem compound represented by the following general formula (I): ##STR1## wherein each symbol is as defined in the specification or a salt thereof, which has antimicrobial activity against Helicobacter pylori, and are useful as anti-Helicobacter pylori agents, anti-gastritis agents, anti-ulcer agents and anti-cancer agents.

Abstract: A process to prepare the E isomer of a 3-substituted (6R,7R)-7-phenyl-acetamido-ceph-3-em-4-carboxylic acid from a mixture of the E and Z-isomer of either the corresponding tert-butyl or the corresponding 4-methoxybenzyl ester of a 3-substituted (6R,7R)-7-phenylacetamido-ceph-3-em-4-carboxylate, characterized by the application of a compound selected from the group titanium tetrachloride, tin tetrachloride and tellurium tetrachloride.

Abstract: Process for purifying 7-substituted aminodeacetoxycephalosporins through the use of filter membranes. A process for purification by ultrafiltration and/or nanofiltration with a cut-off for molecular weights over 10,000 Dalton and preferably over 2000 Dalton is described. For example cephalosporin-G of increased purity, represented by a 6-8% increase in the HPLC titre, with a reduction of 50% in absorbance, is obtained using this technique. The invention makes it possible for the purified products to be used directly in the synthesis of other antibiotic compounds without the need for intermediate isolation.

Abstract: The present invention includes novel compounds of formula ##STR1## where A, B, D, and E are selected from the group consisting of carbon, nitrogen and sulfur, R.sup.99 is selected from the group consisting of sulfur, SO, SO.sub.2, NH, N-alkyl, oxygen, C.dbd.C (cis or trans), and C.tbd.C, and R.sup.12 is NR.sup.13 R.sup.14, ##STR2## The invention also includes the pharmacologically acceptable salts which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to .beta.-lactam antibiotics and are useful as antibacterial agents. The invention also relates to novel intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.

Abstract: The present invention includes novel compounds of formula ##STR1## where R.sup.99 is selected from the group consisting of sulfur, SO, SO.sub.2, NH, N-alkyl, oxygen, C.dbd.C (cis or trans), and C.tbd.C, and R.sup.12 is ##STR2## The invention also includes the pharmacologically acceptable salts which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to .beta.-lactam antibiotics and are useful as antibacterial agents. The invention also relates to novel intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.

Abstract: The invention provides novel cephalosporin derivatives of the formula (I) ##STR1## and salts thereof for use in pharmaceutical compositions. Also novel precursors for synthesis of the cephalosporins are disclosed.

Abstract: The present invention includes novel compounds of formula where A, B, D, and E are selected from the group consisting of carbon, nitrogen and sulfur, R.sup.99 is selected from the group consisting of sulfur, SO, S0.sub.2, NH, N-alkyl, oxygen, C.dbd.C (cis or trans), and C.tbd.C, and R.sup.12 is NR.sup.13 R.sup.14, ##STR1## The invention also includes the pharmacologically acceptable salts which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to .beta.-lactam antibiotics and are useful as antibacterial agents. The invention also relates to novel intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.

Abstract: The present invention includes novel compounds of formula ##STR1## where G, H, J, L and M are carbon or nitrogen, R.sup.99 is selected from the group consisting of sulfur, SO, SO.sub.2, NH, N-alkyl, oxygen, C.tbd.C (cis or trans), and C.tbd.C, and R.sup.12 is NR.sup.13 R.sup.14, ##STR2## The invention also includes the pharmacologically acceptable salts which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to .beta.-lactam antibiotics and are useful as antibacterial agents. The invention also relates to novel intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.

Abstract: An industrially excellent, novel process for producing cephem compounds which are useful as medicines, particularly, antibiotics and represented by the following formula (III): ##STR1## wherein R.sup.1 means either group represented by the following formula: ##STR2## R.sup.2 denotes a carboxyl group or a carboxyl anion, and R.sup.3 stands for a lower alkyl group, a halogen atom, a lower alkyl group substituted by an aliphatic acyloxy group having 1-6 carbon atoms, or any one of the groups represented by the following formulae: ##STR3## which comprises reacting in water a 3-cephem-4-carboxylate represented by the following formula (I): ##STR4## or a salt thereof with an acid chloride represented by the formula (II), R.sup.1 COCl.

Abstract: This invention relates to reactive derivatives of 2-(2-aminothiazol-4-yl)-2-methoxyimino acetic acid and 1H-tetrazol-1-acetic acid of the following general formula I, ##STR1## wherein ##STR2## as well as to use thereof in the manufacture of cephalosporin antibiotics such as cefotaxime, ceftriaxone and cefazolin.

Abstract: A compound selected from the group consisting of a syn isomer of a compound of the formula ##STR1## in the R or S form or in the form of an R, S mixture wherein R us selected from the group consisting of ##STR2## R and R' are individually selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, halogen, CO.sub.2 --Q, ##STR3## CH.sub.2 --SQ, Q and Q' are individually hydrogen or alkyl of 1 to 4 carbon atoms, P, P' and P" are individually alkyl of 1 to 4 carbon atoms optionally substituted by one of the substituents R and R' the dotted line indicating that P and P' can optionally form with the nitrogen atom to which they are linked a heterocycle with 5 or 6 links, R.sub.b and R.sub.c are individually selected from the group consisting of an equivalent of an alkali metal, an alkaline earth metal, magnesium, ammonium and an amine organic base or A and A' are the remainder of an easily cleavable ester group or CO.sub.2 A is CO.sub.

Abstract: An efficient process for de-esterification has been provided for by application of special tetrahalogenides. By applying this process a new compound, viz. cefesone, and especially the E-isomer thereof, has been prepared.

Abstract: Compounds, represented by the following formula (I), having a .beta.-(substituted or unsubstituted imidazo?5,1-b!thiazolyl)vinyl group at the 3-position of the cephem ring and a salt and an ester thereof are disclosed. The compounds have antibacterial activity against a very wide spectrum of bacteria and potent antibacterial activity against Gram-positive bacteria, Gram-negative bacteria, and resistant bacteria. ##STR1## wherein X represents CH or N, R.sup.1 represents a hydrogen atom or an amino protective group, R.sup.2 represents a hydrogen atom, a C.sub.1-6 alkyl group, a C.sub.3-7 cycloalkyl group, or a hydroxy protective group, R.sup.3 is absent or represents a hydrogen atom, a salt forming cation, or a carboxyl protective group, R.sup.4, R.sup.5, and R.sup.6, which may be the same or different, each independently represent a hydrogen atom or a C.sub.1-6 alkyl group, R.sup.7+ is absent or a cation of a C.sub.1-6 alkyl, and n is an integer of 0 to 1.

Abstract: A process for preparing certain cephalosporin antibiotics, namely, cefotaxime, cefetemet, and ceftriaxone sodium comprising acylation of 7-amino-3-cephem-4-carboxylic acid derivatives with 2-mercapto-5-methyl-1,3,4-thiadiazolyl-(Z)-2-(2-aminothiazol-4-yl)-2-metho xyiminoacetate having the formula: ##STR1##

Abstract: A cephalosporin derivative which has a substituted or unsubstituted 2-(5-thiazolyl)vinyl group at the 3-position and is represented by the following formula (I) ##STR1## wherein X is CH or N, R.sup.1 is an amino group or a protected amino group, R.sup.2 is a hydrogen atom or a hydroxyimino-protecting group, R.sup.3 is a hydrogen atom, a salt-forming cation or a carboxyl-protecting group, R.sup.4 is a hydrogen atom, and R.sup.5 is a hydrogen atom, a lower alkyl group, a halo-(lower)alkyl group or a halogen atom, is now synthetised as a cephem compound which exhibits excellent antibacterial activities and is useful as a therapeutic agent for various bacterial infections.

Abstract: The present invention relates to compounds of formula I ##STR1## wherein R.sup.1 is a group selected from 2-, 3-, and 4-hydroxyphenyl, 3-nitrophenyl, and 3-fluoro-4-hydroxyphenyl; as well as readily hydroyzable esters thereof, pharmaceutically acceptable salts of said compounds and hydrates of the compounds of formula I and of their esters and salts.

Abstract: The present invention includes (7R)-7-(acylamino)-3-(substituted-pyridinyl)-3-cephem-4-carboxylic acids or their pharmacologically acceptable salts which exhibit antibiotic activity against methicillin-resistant bacteria and are therefore useful as antibacterial agents.

Abstract: A syn isomer in (R) or (S) form or a mixture thereof of a compound of the formula ##STR1## syn isomer, in the (R) or (S) form or in the form of an (R,S) mixture, in the form of an integral salt or their salts with organic or mineral acids wherein the substituents are as defined in the application and having antibacterial properties.

Abstract: Anhydrous and crystalline free acid form of the cephalosporin antiobiotic ceftiofur, processes for its manufacture, and pharmaceutical composition containing it are provided.

Abstract: The present invention relates to benzathine salts of cefonicid, a member of the cephalosporin family of antibiotics, which are crystalline.

Abstract: The present invention includes novel (7R)-7-(acylamino)-3-(arylthio)-3-cephem-4-carboxylic acids or their pharmacologically acceptable salts which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to .beta.-lactam antibiotics and are useful as antibacterial agents. The invention also relates to novel intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.

Abstract: A stoichiometric acid moiety transfer reaction for the preparation of an acid salt of an amine compound is disclosed. The acid moiety transfer reaction provides amine acid salts of high purity and having crystalline structure of uniform size and shape.

Abstract: Compounds represented by the following formula (I), that is, cephem derivatives having substituted or unsubstituted imidazo[5,1-b]thiazolium-6-yl as a substituent at the 3-position of the cephem ring: ##STR1## wherein X represents CH or N, R.sup.1 represents H, alkyl, alkenyl or the like, and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 represent H, alkyl, carbamoyl, amino or the like. The above compounds have excellent antibacterial activity, and useful as medicines for the treatment of various infectious diseases caused by bacteria.

Abstract: The present invention relates to new cephalosporin compounds of the formula (I), particularly 3-position of cephem rings thereof substituted with new thione compounds and pharmaceutically acceptable salts thereof, which have broad antibacterial activities against both Gram-positive and Gram-negative bacteria, and the said compounds can be prepared by reacting the compounds of the formula (II) with the new thione compounds of the formula (III). ##STR1## wherein R.sub.1 is a C.sub.1-4 alkyl(preferably methyl or ethyl), C.sub.3-4 alkenyl(preferably allyl), C.sub.3-4 alkynyl (preferably propargyl) group or --C(R.sup.a) (R.sup.b)CO.sub.2 H(preferably --C(CH.sub.3).sub.2 CO.sub.2 H or --CH.sub.2 CO.sub.2 H), wherein R.sup.1 and R.sup.b, same or different, are a hydrogen atom or a C.sub.1-4 alkyl group;R.sub.2 is a C.sub.1-4 alkyl(preferably methyl or ethyl), C.sub.3-4 alkenyl(preferably allyl), C.sub.3-4 cycloalkyl(preferably cyclopropyl) group or carboxyalkyl(preferably --CH.sub.2 CO.sub.2 H) group;R.sub.

Abstract: A method for the acylation of the 7-amino group of the cephalosporanic ring, according to which a 7-ACA amino thiazolyl protected adduct is prepared by acylating said amino group by an aminothiazolyl acetic acid whose amino group has been protected by a phenyl acetyl or a phenoxy acetyl group, the amino group being then deprotected by aqueous hydrolysis in the presence of penicillin G amidase or respectively penicillin V amidase.

Abstract: Novel amidine salts of 7-Amino-3-hydroxymethyl-3-cephem-4-carboxylic acid (=HACA), particular guanidine and diaza-bicyclo-alkylene salts, are useful as intermediates in the synthesis of cephalosporins.

Abstract: Various 3-substituted 3-cephems useful as anti-bacterial agents are provided, Also provided are pharmaceutical compositions comprising same and methods for treating bacterial infections in man and other animals.

Abstract: Cephem derivatives of the general formula ##STR1## is which the R.sub.2 O group is in the syn-position, a process for their manufacture and pharmaceutical formulations which are active against bacterial infections and contain these compounds.