Pentadecanoyl chloride (I) is treated with NaN3 to form the corresponding acyl azide (II), which undergoes Curtius rearrangement to isocyanate (III) upon heating in toluene. Coupling of isocyanate (III) with aminocarnitine (IV) then produces the title urea derivative.
(R)-Aminocarnitine (I) was esterified with HCl in refluxing isobutanol to afford the isobutyl ester (II). Acylation of amino ester (II) with dodecanesulfonyl chloride (III) in the presence of triethylamine provided the corresponding sulfonamide (IV). The title compound was then obtained by basic hydrolysis of the isobutyl ester group of (IV).