Diphosphite Ligand Synthesis via Controlled Phosphorochloridite Contacting
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Solution Overview
Problem
Current methods for producing bidentate phosphite ligands in the synthesis of adiponitrile (ADN) result in low catalyst activity and high nickel consumption, with challenges in controlling temperature and process complexity, leading to increased operating costs and impurity levels.
Innovation Solution
A method involving the controlled contacting of a phosphorochloridite with a bisaryl compound and a tertiary organic amine, with serial additions to manage mole percentages of phosphorus-containing side-products, aiming to produce a diphosphite ligand structure with reduced impurities and improved yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If monodentate phosphite ligands are used in nickel catalysts, then the catalyst can be formed, but the catalyst activity is low and nickel consumption is high
Solution Approach 1:
The patent uses bidentate phosphite ligands that contain two phosphorus donor atoms within a single ligand structure, creating a composite material that forms more effective nickel-ligand complexes. This composite approach allows one ligand molecule to coordinate with the metal center through multiple binding sites, enhancing catalyst activity and reducing the amount of nickel required for effective catalysis.
2Productivity
If traditional diphosphite synthesis methods are used with two reaction steps, then the desired product can be formed, but the process complexity increases and operating costs rise
Solution Approach 1:
The patent combines two separate reaction steps into a single concerted reaction step. Instead of first preparing phosphorochloridite and then reacting it with difunctional alcohol in separate steps, the invention directly reacts phosphorus trichloride with difunctional alcohol in the presence of base to form the diphosphite product, eliminating the intermediate isolation and purification steps.
Solution Approach 2:
The patent incorporates preliminary action by pre-mixing all reactants (phosphorus trichloride, difunctional alcohol, and base) before initiating the reaction. This pre-mixing ensures proper stoichiometry and reaction conditions are established before the reaction begins, allowing the concerted reaction to proceed efficiently in one step without requiring intermediate handling.
3Manufacturing precision
If low temperature synthesis is used to control viscosity, then product selectivity improves, but operating costs and process complexity significantly increase
Solution Approach 1:
The patent changes the reaction parameters by conducting the reaction at ambient or elevated temperatures rather than low temperatures. This parameter change is made possible by the concerted reaction mechanism, which maintains good selectivity through the inherent chemistry of the direct reaction between phosphorus trichloride and difunctional alcohol, eliminating the need for complex low-temperature control systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves higher yields of diphosphite ligands with lower impurity levels, enabling more efficient catalyst formation for hydrocyanation reactions and reducing operational costs by minimizing temperature-related issues and impurity concentrations.
Implementation Method 1
contacting a phosphorochloridite of the following structure, with a compound having the chemical structure X-OH and a tertiary organic amine to provide a final reaction mixture including the phosphorus-containing ligand structure
Data Source
AI summary
Claimed is a process for producing a phosphorus-containing ligand, preferably a diphosphite ligand structure (DLS) such as structure I. The method includes contacting a phosphorochloridite (structure II) with a compound having the structure X-OH (which can be a bisaryl compound), and a tertiary organic amine to provide structure I' and as prefered embodiment structure I.