Abstract: Provided is a process for preparing a cephem compound of the formula: ##STR1## wherein R.sup.3 is hydrogen or methoxy, R.sup.4 is hydrogen or a residue of a nucleophilic compound, R.sup.5 is hydroxyl or a protected hydroxyl, and R.sup.8 is hydrogen or halogen, or a pharmaceutically acceptable salt or ester thereof, which comprises introducing an acyl group of the formula: ##STR2## wherein R.sup.5 and R.sup.8 are as defined above into the amino group of the molecule of the formula: ##STR3## wherein R.sup.3 and R.sup.4 are as defined above or a salt or ester thereof.

Abstract: Broad spectrum antibiotics are provided which are compounds of the formula: ##STR1## wherein R.sup.4 is a residue of a nucleophilic compound and R.sup.5 is hydroxyl or protected hydroxyl; or a pharmaceutically acceptable salt or ester thereof.

Abstract: Broad spectrum antibiotics are provided which are compounds of the formula: ##STR1## wherein -W-R is a residue of a nucleophilic compound and R.sup.5 is hydroxyl or protected hydroxyl, or a pharmaceutically acceptable salt or 4-carboxy ester which is the alkoxymethyl, .alpha.-alkoxyethyl, .alpha.-alkoxy-.alpha.-substituted methyl, alkylthiomethyl, acyloxymethyl or .alpha.-acyloxy-.alpha.-substituted methyl ester thereof.

Abstract: The compounds of the formula: ##STR1## wherein R.sup.1 is hydrogen, amino, isonitrile or an organic residue bonded through nitrogen; R.sup.2 is carboxy or a group derivable therefrom; X is hydrogen, methoxy, formylamino, alkyl which may be substituted, alkylthio in which the sulfur atom may be oxidized or azido, or forms a double bond together with the adjacent carbon atom; provided that when R.sup.1 is acetylamino or amino and X is hydrogen, R.sup.2 is not para-nitrobenzyloxycarbonyl or benzhydryloxycarbonyl, or a pharmaceutically acceptable salt thereof, exhibit excellent antimicrobial activity, and are utilized as antimicrobial agents.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 where R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula ##STR2## wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 wherein R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula ##STR2## wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmeceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: A 2-azetidinone derivative having a group of the formula ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each represents a hydrogen atom, alkyl, aryl or arylalkyl which may have a substituent at the 1-position and an amino group, at the 3-position, which may be acylated or protected, its salt or ester, and methods of producing the same, (1) a method comprising subjecting a 2-azetidinone derivative having a group of the formula ##STR2## wherein the symbols are as defined above at the 1-position and an amino group at the 3-position, its salt or ester to an acylation or protective-group introduction reaction, and (2) a method comprising reacting a 2-azetidinone derivative having a hydroxy group at the 1-position and an amino group, at the 3-position, which may be acylated or protected, or its salt with a compound of the formula ##STR3## wherein W is a halogen atom; other symbols are as defined above, its salt or ester.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 wherein R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula ##STR2## wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: Novel 1-sulfo-2-oxoazetidine derivatives and their production and use.These 1-sulfo-2-oxoazetidine derivatives exhibit excellent antimicrobial activity against gram-positive and gram-negative bacteria, and .beta.-lactamase inhibitory activity, thus being of value as a prophylactic or therapeutic agent for infectious diseases in mammals.

Abstract: 4-Cyano-2-azetidinone derivatives represented by the formula ##STR1## wherein R.sup.1 is an amino group which may be acylated or protected, X is a hydrogen atom or a methoxy group and W is a hydrogen atom or a sulfo group, and methods of producing the same, for example, as represented by ##STR2## wherein R.sup.2 is an acylated or protected amino group, Y is a halogen atom or a group having the formula --OCOR.sup.3, --SCOR.sup.3 or --S(O).sub.n --R.sup.3 (R.sup.3 being a hydrocarbyl group and n an integer 1 or 2), R.sup.4 is an amino group which may be acylated or protected and X is as defined above. Compounds [I] are useful as advantageous intermediates for the synthesis of optically active 4-substituted-2-azetidinone derivatives, and, when W=SO.sub.3 H, [I] are also useful as antimicrobial agents and as beta-lactamase inhibitors.

Abstract: The compounds are of the class of esters of 7-[2-(2-aminothiazol-4-yl-)-2-(syn)methoxyiminoacetamido] cephalosporin derivatives, including lower alkoxymethyl, .alpha.-lower alkoxy-.alpha.-substituted methyl, lower alkylthiomethyl, acyloxymethyl, ethoxycarbonyloxy-1-methylmethyl and .alpha.- acyloxy-.alpha.-substituted methyl esters. The compounds are useful against a broad spectrum of bacteria, particularly gram-negative bacteria, and may be administered in the form of injections, capsules, tablets and granules.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 wherein R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula --OR.sub.5, ##STR2## or --S--S--R.sub.5 wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: Compounds of the formula ##STR1## are useful as intermediates in preparing 1-sulfo-2-oxoazetidine compounds having the carbamoyloxymethyl group at the 4-position. The final product compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: Novel cephem compounds of the formula: ##STR1## wherein R.sup.4 is a residue of a nucleophilic compound selected from hydroxyl, mercapto, cyano, azido, amino, carbamoyloxy, carbamoylthio and thiocarbamoyloxy, said group being unsubstituted or substituted by alkyl of up to three carbons, and R.sup.5 is hydroxyl or lower alkoxy, or a pharmaceutically acceptable ester thereof, have strong antibiotic properties against a wide variety of microorganisms.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 wherein R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula --OR.sub.5, ##STR2## or --S--S--R.sub.5 wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sup.1 is a hydrogen atom or a lower alkyl group and R.sup.2 is a hydrogen atom or an ester residue, said derivative having the (3S,4S)-configuration; and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: 4-Cyano-2-azetidinone derivatives represented by the formula ##STR1## wherein R.sup.1 is an amino group which may be acylated or protected, X is a hydrogen atom or a methoxy group and W is a hydrogen atom or a sulfo group, and methods of producing the same, for example, as represented by ##STR2## wherein R.sup.2 is an acylated or protected amino group, Y is a halogen atom or a group having the formula --OCOR.sup.3, --SCOR.sup.3 or --S(O).sub.n --R.sup.3 (R.sup.3 being a hydrocarbyl group and n an integer 1 or 2), R.sup.4 is an amino group which may be acylated or protected and X is as defined above. Compounds [I] are useful as advantageous intermediates for the synthesis of optically active 4-substituted-2-azetidinone derivatives, and, when W=SO.sub.3 H, [I] are also useful as antimicrobial agents and as beta-lactamase inhibitors.

Abstract: Disclosed are compounds of the general formula: ##STR1## wherein R.sub.1 is amino, an acylated amino or a protected amino group, X is hydrogen or methoxy, and R' is hydrogen, R or R.sup.4 wherein R is an organic residue attached to the azetidine ring through a carbon atom therein and R.sub.4 is azido, a halogen, an amino group which may optionally be acylated or a group of the formula --OR.sub.5, ##STR2## or --S--S--R.sub.5 wherein R.sub.5 is an organic residue and n is 0, 1 or 2, and pharmaceutically acceptable salts and esters thereof.The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.

Abstract: A compound of the formula:R--CH.dbd.N--SO.sub.3.sup..crclbar. Z.sup..sym. (II)[R is an organic residue derived by removal of one hydrogen atom attached to a carbon atom of an organic compound; Z.sup..sym. is a lipophilic quaternary ammonium group], and a method of producing a 2-azetidinone-1-sulfonic acid compound of the formula: ##STR1## [R and Z.sup..sym. have the same meanings as respectively defined above; R.sup.1 is an acylated or protected amino group or an azide group], being a useful intermediate for the production of antimicrobial agents having excellent antimicrobial and .beta.-lactamase-inhibitory activities, by reacting a compound (II) with a reactive derivative of a carboxylic acid of the formula:R.sup.1 --CH.sub.2 COOH[R.sup.1 is the same meaning as defined above] in the presence of a base.

Abstract: A 7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido]cephalosporin derivative of the formula; ##STR1## wherein R.sub.3 is hydrogen or a residue of a nucleophilic compound; R.sub.2 NH is an amino group which may optionally be protected, pharmaceutically acceptable salt or ester thereof, is found to have excellent anti-bacterial activity against a broad spectrum of bacteria inclusive of gram-negative bacteria such as Escherichia coli, Serratia marcescens, Proteus rettgeri, Enterobacter cloacae and Citrobacter freundii. Thus, this compound may be used for an antibacterial agent in therapeutical purposes.