1) 5-Indansulfonamide (I) is converted to ethyl N-(5-indansulfonyl)carbamate (II) with ethyl chloroformate and potassium carbonate in refluxing 2-butanone, which is then reacted with 4-chloroaniline (III) in toluene at reflux to provide sulofenur. 2) Alternatively, (I) can be converted to its anion with NaOH in aqueous acetone, then reacted with 4-chlorophenylisocyanate (IV) to give sulofenur directly.