PROCESS FOR OBTAINING ACYLDERIVATIVE

Cephalosporin derivatives of the general formula in which m represents 0, 1 or 2, R represents hydrogen or an acyl group, R represents hydrogen, lower alkoxy, lower alkylthio or lower alkanoylamino, R represents hydrogen, lower alkyl, lower alkenyl, C3-C7-cycloalkyl, halogen-lower alkyl or mono-, di- or trihalophenyl; Z represents R -C or nitrogen, R represents hydrogen or halogen, or R and R together represent a C3-C5-alkylene group, a C2-C4-alkylenemonooxy group or a C1-C2-alkylenedioxy group, R represents hydrogen, halogen, lower alkyl or an optionally substituted 5- or 6-membered heterocyclic ring having 1, 2 or 3 oxygen, nitrogen and/or sulphur atoms and R represents hydrogen or halogen or R and R together represent a C1-C4-alkylenedioxy group, and easily hydrolysable esters and salts of these compounds and hydrates of the compounds of the formula I or of their esters and salts, and a process for the preparation of these compounds and corresponding pharmaceutical preparations. The products have antimicrobial activity.