M 2239 (OTTO) Methyl thioglycolate Cas 2365-48-2 - used in the preparation of 3-carbomethoxy-4- oxotetrahydrothiopyran, 2- and 4-carbomethoxy-3-oxotetrahydrothiophene. M 2239 (OTTO) Methyl thioglycolate Cas 2365-48-2 - used to prepare methyl thioglycolate and aminoethanethiol conjugated gold nanorods.