Friedel-Crafts acetylation of acetaminophen (I) using acetyl chloride and AlCl3 gave acetophenone (II). Subsequent condensation of (II) with N-(tert-butoxycarbonyl)-4-piperidone (III) in the presence of pyrrolidine provided the spirochroman-2,4'-piperidine (IV), from which the diamine (V) was obtained by acid hydrolysis. The piperidine amino group of (VI) was then alkylated with 1-(2-bromoethyl)naphthalene (VI) to afford (VII). Finally, condensation of the remaining amino group of (VII) with the sulfonyl chloride (VIII) furnished the title sulfonamide.