Novel cephalosporin compounds and process for preparing the same

A cephalosporin compound represented by the following formula (I):

• 17
• in which
• R1 and R2 each independently represent hydrogen, halogen, C1-6 alkyl, C1-6 alkylthio, aryl, arylthio, or C5-6 heteroaryl containing one or two hetero atoms selected from the group consisting of nitrogen atom and oxygen atom;
• R3 represents hydrogen or a carboxy-protecting group;
• Q represents S, O, CH2, NH or NR wherein R is hydrogen, C1-6 alkyl or benzyl;
• Z represents CH or N;
• n denotes an integer of 1 or 2;
• and
• Ar represents a heteroaryl group represented by one of the following formulas:
• 18
• wherein X, Y, W, A, B, D, E, G and I independently of one another represent N or C (or CH), provided that the six-membered ring forms a pyrimidine structure;
• R4 represents hydrogen, C1-4 alkyl, or amino substituted or unsubstituted with a substitutent selected from the group consisting of C1-6 alkyl and C1-6 hydroxyalkyl;
• R5 and R6 each independently represent hydrogen, hydroxy, C1-4 alkyl, C1-6 alkylthio substituted or unsubstituted with a substitutent selected from the group consisting of C1-6 alkyl, C1-6 hydroxyalkyl and C1-6 aminoalkyl, or amino substituted or unsubstituted with a substitutent selected from the group consisting of C1-6 alkyl, C1-6 hydroxyalkyl and C1-6 aminoalkyl;
• R7, R8, R9, R10 and R11 independently of one another represent hydrogen, C1-6 alkyl, or amino substituted or unsubstituted with a substitutent selected from the group consisting of C1-6 alkyl, C1-6 hydroxyalkyl and C1-6 aminoalkyl;
• and
• denotes a single bond or a double bond;
• or pharmaceutically acceptable non-toxic salt, physiologically hydrolysable ester, hydrate, solvate or isomer thereof.