M 1617 (OTTO) 2-Mercapto benzothiazole, GR 99%+ Cas 149-30-4 - used in the past in the gold-mining industry for the froth flotation of gold from ore residue as part of the extraction process. M 1617 (OTTO) 2-Mercapto benzothiazole, GR 99%+ Cas 149-30-4 - used in the vulcanization of rubber.