C-10213-Go has been synthesized from 1-methyl-2-mercaptoimidazole (I). When (I) is methylated with methyl iodide it gives the corresponding thiomethyl derivative (II). Nitration of (II) yields the nitro derivative (III). Oxidation of (III) with monoperphthalic acid gives the sulfone (IV). Condensation of (IV) with 1-methanesulfonyl-2-imidazolidinone (VI) in the presence of sodium hydride affords C-10213-Go.