Abstract:
Process for the manufacture of 7-amino-3-cephem-4-carboxylic acids and the esters thereof of the formula I
in which A stands for hydrogen, alkyl, acyloxy, alkyloxy or hydroxy and R stands for hydrogen, optionally substituted linear or branched alkyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, alkoxyalkyl, acryloxyalkyl, aroylalkyl, or a heterocyclic radical and the salts thereof which comprises reacting 7-acylamino-3cephem-4-carboxylic acid esters of the general formula II
in which R'' stands for optionally substituted alkyl, aryl, aralkyl, aryloxyalkyl, alkoxyalkyl or a heterocyclic radical and R'''' has the meaning given for R but cannot stand for hydrogen and A is defined as above, in an inert solvent with a silylating agent in the presence of a base, converting the amido group activated by the silylation into the iminohalide by adding a halogenating agent, allowing it to react with an alcohol to yield the iminoether hydrohalide, hydrolyzing the iminoether hydrohalide and optionally splitting the 7-amino-3-cephem-4carboxylic acid ester of the general formula I to yield the free acid, the esters obtained being valuable intermediates.
Abstract:
IN WHICH R1, R2 and R3 represent hydrogen or lower alkyl groups and R1 and R2 may form together an alkylene group which may be substituted, R4 represents a linear or branched alkyl radical of 1 to 5 carbon atoms, a cyclo-alkyl radical of 3 to 7 carbon atoms which may be interrupted by heteroatoms, X represents a single bond or NH, A represents a phenylene or thienylene group which may be substituted and Y represents a single bond or oxygen, and their physiologically tolerated salts; the novel compounds have very good anti-bacterial properties.
Acylamino-cephem-carboxylic acids of the general formula