4-(2-Bromoethyl)benzoic Acid is a reagent in the synthesis of 5-thia-2,6-diamino-4(3H)-oxopyrimidine as potent inhibitors of glycinamide ribonucleotide transformylase (GART). Also, it is a reagent in the synthesize pyrrole[3,2-d]pyrimidine folate analogs, as potential anticancer agents.