Highly selective process for producing organodiphosphites

1. A method for producing a diphosphite of Structure I,

comprising the steps of:

contacting a phosphorochloridite of Structure II,

with a bisaryl compound selected from the group consisting of Structure III, Structure IV, and Structure V,

and a tertiary organic amine, comprising a basic nitrogen atom or a plurality of nitrogen atoms, to produce a reaction mixture comprising a diphosphite of Structure I and at least one phosphorus-containing co-product in the reaction mixture selected from the group consisting of P(OR 1 )(OR 2 ) 2 , P(OR 1 ) 2 (OR 2 ), P(OR 1 ) 3 , P(OR 2 ) 3 , a compound of Structure VIa, and a compound of Structure VIb,

wherein,

the contacting is done by at least one contacting method selected from the group consisting of,

(i). feeding the bisaryl compound to a mixture of phosphorochloridite and tertiary organic amine, and

(ii). feeding the bisaryl compound and the tertiary organic amine separately or as a mixture to the phosphorochloridite;

and the contacting step is carried out by controlling the feeding such that a first mole ratio is maintained at equal to or greater than 2.0 during at least an initial stage and a final stage of the contacting step, wherein the first mole ratio is defined as moles of phosphorochloridite in the reaction mixture divided by moles of bisaryl compound fed to the reaction mixture,

and the contacting step is carried out by controlling the feeding such that a second mole ratio is at least 1.0 during the contacting step, wherein the second mole ratio is defined as moles of basic nitrogen atoms from the tertiary organic amine fed to the reaction mixture divided by moles of phosphorochloridite in the reaction mixture, wherein the contacting is performed at a temperature of the reaction mixture of from greater than 10° C. to less than or equal to about 110° C.; and

the method is characterized by

(1) controlling the feeding such that the first mole ratio is from 2.1 to 2.7 during the stage of the contacting wherein phosphorochloridite conversion is from 90% to 100%; and

(2) optionally, controlling the feeding such that a phosphorochloridite concentration is greater than or equal to 0.02 moles per liter in the reaction mixture during the stage of the contacting wherein phosphorochloridite conversion is from 0% to 90%;

wherein,

less than 30% of the total phosphorus in the reaction mixture is in the form of the at least one phosphorus-containing co-product, and 7.9% or less of the total phosphorus in the reaction mixture is in the form of the phosphorus-containing co-products having Structures VIa and VIb,

wherein in Structures I to V and the at least one phosphorus-containing co-product,

R 1 and R 2 are the same or different, substituted or unsubstituted, monovalent aryl groups; each of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , and R 12 is independently selected from the group consisting of hydrogen, alkyl, aryl, heteroaryl, aryloxy, heteroaryloxy, alkyloxy, alkoxyalkyl, acetal, carboaryloxy, carboalkoxy, arylcarbonyl, alkylcarbonyl, oxazole, amine, amide, nitrile, mercaptyl, and halogenyl groups; and O-Q-O − is a dianion of the bisaryl compound.

2. The method of claim 1 wherein the reaction mixture further comprises at least one aromatic hydrocarbon solvent.

3. The method of claim 1 wherein control method (2) further comprises controlling the feeding such that the phosphorochloridite concentration is from 0.02 and 2.0 moles per liter in the reaction mixture during the stage of the contacting wherein phosphorochloridite conversion is from 0% to 90%.

4. The method of claim 1 further comprising controlling a second mole ratio from 1.0 to 1.5 in the reaction mixture during any stage of the contacting.

5. The method of claim 1 further comprising feeding the bisaryl compound to the phosphorochloridite at a feed rate between 0.04 and 10 molar equivalents per hour, relative to total moles of phosphorochloridite undergoing the contacting.

6. The method of claim 1 further comprising feeding the bisaryl compound to the phosphorochloridite as a bisaryl solution comprising the bisaryl compound and hydrocarbon solvent.

7. The method of claim 6 wherein the reaction mixture further comprises an upper liquid surface, the contacting further comprises providing a stirring shaft comprising at least one impeller attached to the stirring shaft wherein at least one impeller is located below the upper liquid surface, and the adding further comprises providing rotational energy to the stirring shaft to mechanically stir the reaction mixture.

8. The method of claim 7 further comprising adding the bisaryl solution to the phosphorochloridite by at least one mixing method selected from the group consisting of,

feeding the bisaryl compound to the reaction mixture above the upper liquid surface by flowing the bisaryl solution through at least one liquid distributor that disperses the bisaryl solution over at least a portion of the upper surface;

feeding the bisaryl compound to the reaction mixture above the upper liquid surface by flowing the bisaryl solution through at least one liquid distributor that disperses the bisaryl solution over at least a portion of the upper surface and feeding the tertiary organic amine to the reaction mixture below the upper liquid surface;

feeding the bisaryl compound to the reaction mixture by flowing the bisaryl solution through at least one feed line that directs the bisaryl solution toward an impeller located below the upper liquid surface;

feeding the bisaryl compound to the reaction mixture by flowing the bisaryl solution through at least one feed line that directs the bisaryl solution toward an impeller located below the upper liquid surface and feeding the tertiary organic amine to the reaction mixture by flowing the tertiary organic amine through at least one feed line that directs the bisaryl solution toward an impeller located below the upper liquid surface; and

the bisaryl solution further comprises at least a portion of the tertiary organic amine fed to the reaction mixture and feeding the bisaryl compound to the reaction mixture by flowing the bisaryl solution, further comprising the tertiary organic amine, through at least one feed line that directs the bisaryl solution toward an impeller located below the upper liquid surface.

9. The method of claim 1 wherein the bisaryl compound, the tertiary organic amine, or a combination of the bisaryl compound and the tertiary organic amine, contacting the phosphorochloridite further comprises a total of from 0 ppm to 300 ppm by weight of water.

10. The method of claim 1 further comprising precipitating a tertiary organic amine hydrogen chloride salt from the reaction mixture during the contacting.

11. The method of claim 1 wherein the diphosphite is produced in the reaction mixture with a selectivity between 70% and 100% from the bisaryl compound, wherein, the selectivity equals moles of diphosphite produced in the reaction mixture divided by total moles of the bisaryl compound contacting the phosphorochloridite.

12. The method of claim 1 wherein the first mole ratio is greater than 2.0 during all stages of the contacting step and the second mole ratio is greater than 1.0 during all stages of the contacting step.