Abstract Radiolabelled raloxifene (LY156758) has been prepared by tritium gas hydrogenolysis of a 3-aroyl-bis-brominated precursor. The requisite halogenated intermediate was accessed by regioselective aroylation of benzothiophene 6 with the acid chloride of 3, 5-dibromo-4-[2-(1-piperdinyl) ethoxy] benzoic acid (5). Selective deprotection of the aryl methyl ethers in the presence of the ethoxy side-chain followed by palladium ...
