5-Bromo-3-fluorobenzene-1,2-diol is used as a reagent in the synthesis of N-(hydroxy(pyrrolidinyl)propanyl)pyrrolidinecarboxamide derivatives as glucosylceramide synthase inhibitors.5-Bromo-3-fluorobenzene-1,2-diol is also used in the preparation of 5,5-disubstituted-2-iminopyrrolidine derivatives as thrombin receptor antagonists.