(methylimino)(thioxo)methane 556-61-6 Biomet 33 Degussa methyl isothiocyanate InChI=1/C2H3NS/c1-3-2-4/h1H Isothiocyanatomethane MENCS MTC Methyl Isothiocyanate Methyl mustard oil Trapex methane, (methylimino)thioxo-