The invention provides a
hydrocyanation process for the production of
adiponitrile and other dinitriles having six carbon atoms, the process comprising: a) forming a reaction mixture in the presence of at least one Lewis acid, said reaction mixture comprising ethylenically unsaturated nitrites having five carbon atoms,
hydrogen cyanide, and a catalyst precursor composition, by continuously feeding ethylenically unsaturated nitrites,
hydrogen cyanide, and a catalyst precursor composition; b) controlling X and Z, wherein X is the overall feed
molar ratio of 2-pentenenitriles to all unsaturated nitrites and Z is the overall feed
molar ratio of
hydrogen cyanide to all unsaturated nitrites, by selecting a value for X in the range from about 0.001 to about 0.5, and a value for Z in the range from about 0.5 / 1 to about 0.99 / 1, such that the value of quotient Q, Formula (I), wherein Q is in the range from about 0.2 to about 10, wherein 3PN is 3- pentenenitriles and 4PN is 4-pentenenitrile; and c) withdrawing a
reaction product mixture comprising
adiponitrile; wherein the ratio of the concentration of 2-pentenenitriles to the concentration of 3-pentenenitriles in the reaction mixture is from about 0.2 / 1 to about 10 / 1; wherein the catalyst precursor composition comprises a zero-valent
nickel and at least one multidentate
phosphorus-containing ligand; wherein the multidentate
phosphorus-containing ligand is selected from the group consisting of a phosphite, a
phosphonite, a phosphinite, a
phosphine, and a mixed
phosphorus-containing ligand or a combination of such members; and wherein the multidentate phosphorus-containing ligand gives acceptable results according to at least one protocol of the 2- Pentenenitrile
Hydrocyanation Test Method.