Cefonicid

Cefonicide (or cefonicid) is a cephalosporin antibiotic.
It has a density of 1.92g/cm3.
Synthesis.
Injectable semi-synthetic cephalosporin antibiotic related to cefamandole, q.v. 
Cefonicid is synthesized conveniently by nucleophilic displacement of the 3-acetoxy moiety of 1 with the appropriately substituted tetrazole thiole 2. The mandelic acid amide C-7 side chain is reminiscent of cefamandole.