3-Chloromethyl-benzoic Acid Allyl Ester is an intermediate in the synthesis of 3-[[[3-[4-[(Methylsulfonyl)amino]phenyl]-4-oxo-4H-chromen-7-yl]oxy]methyl]benzoic Acid (M323290), as well as a reagent in the preparation of small-molecule antagonists of IL-2, inhibiting protein-protein binding interacitons.