Condensation between 4-methylsulfonyl-2'-bromopropiophenone (I) and 4-chlorophenylacetic acid (II) in the presence of Et3N/DBU, followed by air oxidation, gives rise to the furanone derivative (III) (1). This is subsequently hydrolyzed with ethanolic NaOH to produce the title keto carboxylate compound (1,2).