Acetaminophen → N-[4-[(5-Bromopentyl)oxy]phenyl]acetamide

A solution of N-(4-hydroxyphenyl)-acetamide (paracetamol) (1) (1.50 g, 0.01 mol) and 1,5-dibromopentane (9) (10.0 ml) in ethyl methyl ketone (25.0 ml) containing potassium carbonate (5.0 g) was stirred for 8 hr at room temperature. The reaction mixture was filtered, residue washed with ethyl methyl ketone and solvent evaporated under reduced pressure to get the residue. The residue was dissolved in chloroform (200.0 ml), washed with 5% sodium hydroxide solution (3×100 ml), water (3×50 ml), dried, filtered and crystallized from methanol to get the desired product N-[4-(5-bromo-pentoxy)-phenyl]-acetamide (11) (2.15 g, 72.15%), mp 110-111° C.