Friedel-Crafts acylation of phenol (I) with nonanoyl chloride (II) in the presence of AlCl3 afforded ketone (III). Aminosulfonyl chloride (V) was prepared by decarboxylation of chlorosulfonyl isocyanate (IV) upon treatment with formic acid. Finally, condensation of the sodium phenolate of (III) with aminosulfonyl chloride (V) furnished the title sulfamate.