US Patent 7309680 Molybdenum-sulfur additives

A process for making an additive comprising one or more oil-soluble or oil-dispersible molybdenum-sulfur compounds, said process comprising the steps of:(I) reacting in a polar medium a reactant molybdenum compound (A) and a source of a ligand (B), which ligand (B) is capable of rendering the or each molybdenum-sulfur compound oil-soluble or oil-dispersible; and(II) reacting a compound (C), which is capable of reacting with labile sulfur, either with (a) the reaction mixture of step (I) after the reaction of (A) and (B) has begun or (b) the product of step (I).