2-[4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl]butyric Acid Ethyl Ester-d5 is labelled 2-[4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl]butyric Acid Ethyl Ester (T302660) which is used as a reagent to prepare N-heterocyclylcarbamates and biphenylisoxazoles as lysophosphatidic acid (LPA) receptor antagonists.