(R)-(+)-α-[(3-Methoxy-1-methyl-3-oxo-1-propenyl)amino]-1,4-cyclohexadiene-1-acetic-d5 Acid Sodium Salt is an intermediate in the synthesis of Cephradine-d5 (C261802). Labelled Cephradine is a first generation cephalosporin antibiotic. Cephradine has broad spectrum of bactericidal activity against infections caused by Streptococcus, Staphylococcus, Diplococcus pneumoniae, Escherichia, Klebsiella, Salmonella, and indole-negative Proteus.