Alkylation of ethyl 4-hydroxybenzoate (I) with 1-(2-chloroethyl)piperidine (II) provided adduct (III). After saponification of the ethyl ester group of (III), the resulting carboxylic acid (IV) was treated with oxalyl chloride to furnish the desired acid chloride (V).

Reaction of 4-bromoaniline (VI) with methanesulfonyl chloride afforded the bis sulfonamido derivative (VII). Palladium-catalyzed coupling of (VII) with 6-methoxybenzo[b]thiophene-2-boronic acid (VIII) then provided the 2-aryl benzothiophene (IX). Subsequent Friedel-Crafts acylation of (IX) with acid chloride (V) in the presence of AlCl3 gave rise to ketone (X). The methyl ether group of (X) was finally cleaved by treatment with ethanethiol and AlCl3.