Abstract: In a seal chain having ring-shaped seals sealed between outer plates and inner plates, by reducing the thickness of the outer plates and the inner plates, a distance between inner side surfaces of the both inner plates and a distance between outer side surfaces of the both outer plates are set to be same as those of a standard chain, and the length of pins is set to be same as that of the standard chain, so that a narrow seal chain in which a standard guide can be used, and a standard attachment can be attached is achieved.

Abstract: New compounds are disclosed having the general formulas (1) and (2): ##STR1## Also described is a process for preparing the compounds of formulas (1) and (2). Further described is a process for preparing a cephalosporin derivative having formula (5): ##STR2## by converting the compound of formula (1) to the compound of formula (2) and then converting the compound of formula (2) to the compound of formula (5).

Abstract: New compounds are disclosed having the general formulas (1) and (2): ##STR1## Also described is a process for preparing the compounds of formulas (1) and (2). Further described is a process for preparing a cephalosporin derivative having formula (5): ##STR2## by converting the compound of formula (1) to the compound of formula (2) and then converting the compound of formula (2) to the compound of formula (5).

Abstract: The present invention relates to a cephem compound of formula (III) shown in the description. The compound is useful as an intermediate for the synthesis of .beta.-lactam antibiotics of new class and also to a process for producing the same. The cephem compound (III) is produced by reacting a cephem compound of formula (I) with a nitrogen-containing compound of formula (II) under acid-capturing conditions. The process can be performed easily under mild conditions.

Abstract: There are provided new cephem compounds (synisomers) represented by the following general formula (I): ##STR1## wherein R.sup.1 means a lower group, R.sup.2 denotes an ester-forming group of the carboxyl group, and the 4-methylthiazolyl group and the cephem moiety are cis to each other relative to the carbon-carbon double bond of the substituted vinyl group in the side chain at the 3-position of the cephem nucleus. The cephem compounds exhibit strong antibacterial activities not only against resistant strains of bacteria and gram-negative bacteria but also against gram-positive bacteria and moreover have very low toxicity.

Abstract: New cephalosporin derivatives of a general formula (I) and non-toxic salts and non-toxic esters thereof are provided: ##STR1## (wherein R represents an acyclic or cyclic lower alkyl group having 1-6 carbon atoms, which may optionally be substituted by a halogen atom; the steric configuration as asterisked (*) includes an optical-active (R)-form or (S)-form or an optical-inactive (RS)-form; n is 0 or 1, n.sup.1 is 0 to 3, n.sup.2 is 0 to 3; and when n.sup.1 is 0, n.sup.2 is 3; when n.sup.1 is 1, n.sup.2 is 2; when n.sup.1 is 2, n.sup.2 is 1; when n.sup.1 is 3, n.sup.2 is 0).The new derivatives of the formula (I) and non-toxic salts and esters thereof have high bactericidal activity with broad antibacterial spectra, and these are useful as active ingredients in bactericides.

Abstract: A new compound, i.e., 14-chlorodaunomycin, and its method of preparation are provided. The new compound, useful as an antitumor agent and as an intermediate in the preparation of (2"R)-4'-O-tetrahydropyranyladriamycin, is obtained by reaction of daunomycin with an alkyl ortho-formate and a brominating agent to produce a 14-bromo-13-dialkylketaldaunomycin, hydrolysis of the latter compound, then adding an excess of a solid metal/chloride to produce an acid addition salt of 14-chlorodaunomycin and concurrently salting out the latter compound from the reaction solution, followed by recovering the 14-chlorodaunomycin acid addition salt.

Abstract: A class of new caphalosporin compounds (syn-isomer) is now provided, which is useful as antibacterial agent and is represented by the general formula (I) ##STR1## wherein R.sup.1 is an amino group or a protected amino group; R.sup.2 is a lower alkyl group, a carboxymethyl group or a protected carboxymethyl group; R.sup.3 is a hydrogen atom, a salt-forming cation or a carboxyl-protecting group; A is an unsubstituted or substituted phenyl group, an unsubstituted or substituted furyl group, an unsubstituted or substituted thiazolyl group or an unsubstituted or substituted 3-lower-alkylthiazolio group, and a pharmaceutically acceptable salt or ester thereof.

Abstract: Cephalosporin compounds having 2-(2-aminothiazol-4-yl)-2{(1S)-carboxyethoxyimino}acetyl group on the side chain at the 7-position thereof and 1-ethylpyridinium-4-ylthiomethyl group on the side chain at the 3-position thereof or non-toxic salts thereof are excellent antibacterial agents for mammals including human. The cephalosporin derivatives have low toxicity.

Abstract: A new cephalosporin compound is now provided, which is useful as antibacterial agent and is represented by the general formula (I) ##STR1## wherein R.sup.1 is an amino group or a protected amino group; R.sup.2 is a hydrogen atom, a salt-forming cation or a carboxyl-protecting group; R.sup.3 is a hydrogen atom, a halogen atom, a lower alkylthio group, a lower alkoxyl group, a vinyl group or a group of the formula: --CH.sub.2 Y where Y is a hydrogen atom, a halogen atom, an acyloxy group, an unsubstituted or substituted heterocyclic thio group or an unsubstituted or substituted pyridinio group, and a pharmaceutically acceptable salt or ester thereof.

Abstract: Disclosed is a novel cephem compound represented by the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and Y are as defined in the specification, which is a useful intermediate for synthesizing various cephalosporin antibiotics having a methoxy group at the 7.alpha.-position thereof. Also disclosed is a process for preparing the same.

Abstract: Sodium 7.beta.-(2D-2-amino-2-carboxyethylthioacetamido)-7.alpha.-methoxy-3-(1-met hyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate heptahydrate and a method of obtaining it from the corresponding carboxylate.

Abstract: Disclosed is a novel cephem compound represented by the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and n are as defined in the specification, which is a useful intermediate for synthesizing various cephalosporin antibiotics having a methoxy group at the 7.alpha.-position thereof. Also disclosed is a process for preparing the same.

Abstract: A novel ester of a cephem compound having a carboxyl group at the 4-position in the nucleus; a process for preparing the same by reacting a cephem carboxylic acid or its salt with a halogenide; and a method for removing the protective group for the carboxyl group in the nucleus of a cephem compound by contacting it with an alcohol, or with an organic solvent in the presence of a Lewis acid.

Abstract: A process for preparing a cephalosporin ester which comprises subjecting an organic halide or an alcohol to reaction with a cephalosporin acid, a cephalosporin acid halide or a salt thereof in the presence of liquid sulfur dioxide.