M 1456 (OTTOKEMI) Magnesium bis(hexamethyldisilazide) , 97% Cas 857367-60-3 -used in chemical research can also be used in the synthesis of ItBu:Mg[N(SiMe3)2, where ItBu = (1,3-di-tert-butylimidazol-2-ylidene), a catalyst for the guanylation reaction of addition of amine to carbodiimide.