Coupling of ibuprofen (I) with N-acetylcysteine (II) via activation with carbonyl diimidazole produced the thioester adduct (III). Reaction of the free carboxyl group of (III) with tetrahydrofuran in the presence of triphenylphosphine and carbon tetrabromide gave rise to the bromobutyl ester (IV). The bromide group of (IV) was finally displaced with silver nitrate to produce the title nitrate ester.