Intermediates for preparing cationic-2-heteroaryl-phenyl-carbapenem antibacterial agents

A compound of the formula:

• ##STR163## wherein;
• R is H or CH.sub.3 ;
• P' is a removable protecting group for hydroxy;
• M is a removable protecting group for carboxy;
• R.sup.a is selected from the group consisting of H, OP', Cl, Br, I, SCH.sub.3, CN, CHO, SOCH.sub.3, SO.sub.2 CH.sub.3, CO.sub.2 M, CH.sub.2 OP' or CONH.sub.2 ;
• and with the proviso that the --CH.sub.2 Z substituent is in the 2- or 3-position of the heteroaromatic ring;
• X is O or S, and
• Z is a leaving group selected from the group consisting of alkylsulfonyloxy, substituted alkylsulfonyloxy, arylsulfonyloxy, substituted arylsulfonyloxy, fluorosulfonyloxy, and halogen.