Ethyl 3-(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoate acts as a reagent in the preparation of N-(3-amino-2-hydroxypropyl)benzenesulfonamide and N-(3-amino-2-hydroxypropyl)thiophenesulfonamide derivatives as calcium-sensing receptor antagonists and parathyroid hormone (PTH) secretion promoters