Cefazaflur stands out among this group of analogues because it lacks an arylamide C-7 side chain (see cephacetrile for another example).
Cefazaflur is synthesized by reaction of 3-(1-methyl-1-tetrazol-5-ylthiomethylene)-7-amino-cephem-4-carboxylic acid (1) with trifluoromethylthioacetyl chloride (2).