- Protected aminothiazolylacetic acid derivatives
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Described is a protected aminothiazolylacetic acid derivative represented by the following formula (I): STR1 wherein A represents a nitrogen atom or a methine group, R1 and R2 may be the same or different and individually represent a hydrogen atom, a lower alkyl group or a substituted or unsubstituted aryl group, R3 represents a lower alkoxy group, a halogenated lower alkoxy group, a triphenylmethoxy group, a lower alkyl group or an acyloxy group, and R4 represents a halogen atom, a hydroxy group, a lower alkoxy group or a substituted or unsubstituted amino group; and salts thereof; as well as processes for the preparation thereof. The protected aminothaizolylacetic acid derivative according to the present invention is an useful intermediate for introducing a 2-(2-aminothiazol-4-yl)-2-alkoxyiminoacetyl group or a 2-(2-aminotiazol-4-yl)-2-alkenoyl group into a cephem skeleton.
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- Cephalosporin derivatives
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Novel 7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido]cephalosporanic acid derivatives of the formula: STR1 wherein R1 NH is an amino group which may optionally be protected, R2 is a halogen atom or a hydroxyl, thiol or amino group which may optionally be substituted; COOR is a carboxyl group which may optionally be esterified, and pharmaceutically acceptable salts thereof, have excellent antimicrobial activity against a broad spectrum of microorganisms including Gram-negative bacteria such as Escherichia coli, Serratia marcescens, Proteus rettgeri, Enterobacter cloacae, Citrobacter freundii. Thus, these compounds may be used as antibacterial agents for therapeutic purposes.
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- 7-[2-(2-Aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporins
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A 7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporin derivative of the formula; STR1 wherein R3 is hydrogen or a residue of a nucleophilic compound; R2 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.
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- [3-Heterocyclic-7-(2-methoxyimino-2-aminothiazolyl) acetamido]cephalosporins
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7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido]cephalosporanic acid derivatives of the formula; STR1 wherein R1 NH is an amino group which may optionally be protected; COOR2 is a carboxyl group which may optionally be esterified; X is oxygen, sulfur or an imino group which may optionally be substituted; B is hydrogen or a hydroxyl, amino, thiol or hydrocarbon group which may optionally be substituted, or a salt thereof, are novel, β-lactamase-resistant and low-toxicity compounds which display excellent activity against a broad spectrum of microorganisms including Gram-negative bacteria such as Escherichia coli, Serratia marcescens, Proteus rettgeri, Enterobacter cloacae, Citrobacter freundii. Thus, these compounds can be used for antibacterial agents in therapeutical purpose.
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