Mono-amidation of Phosphates and Phosphonates via Mild Coupling
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Solution Overview
Problem
The development of phosphoramidates is hindered by harsh reaction conditions, low yields, and difficulties in isolating water-soluble mono-phosphoramidates from water-soluble urea byproducts, with existing methods being inefficient and inconsistent, particularly in the antiviral nucleotide and cancer therapeutic fields.
Innovation Solution
A novel method involving treatment of a compound with dialkylazodicarboxylate, a phosphine reagent, and an amine in an aprotic solvent to generate phosphoramidates under mild conditions, allowing for rapid generation of phosphoramidates in less than 30 minutes for phosphonates and less than 1 minute for phosphates, with good yields and purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional methods are used to prepare phosphoramidates, then the reaction can proceed, but the reaction conditions are harsh and require toxic reagents
Solution Approach 1:
The patent changes the reaction parameters by using mild conditions (room temperature, neutral pH) and non-toxic reagents (EDC, DMAP, NMI) instead of traditional harsh conditions, thereby eliminating harmful factors while maintaining reliable phosphoramidate preparation
Solution Approach 2:
The patent employs readily available, inexpensive reagents such as EDC and DMAP that can be easily handled and disposed of, replacing expensive and toxic reagents while maintaining effective phosphoramidate synthesis
2Reliability
If alternative approaches are used to assemble phosphoramidate fragments, then the reaction can proceed, but the yields are highly inconsistent and poor
Solution Approach 1:
The patent introduces DMAP and NMI as intermediary catalysts that facilitate the coupling reaction between phosphoric acid/phosphonic acid and amine, ensuring consistent and high yields by mediating the reaction process and preventing side reactions
Solution Approach 2:
The patent replaces inefficient fragment assembly approaches with a direct coupling method using carbodiimide chemistry, substituting the mechanical mixing of fragments with a chemically mediated one-step coupling that provides consistent high yields
3Reliability
If peptide coupling strategies are used to prepare phosphoramidates, then the reaction can proceed, but the isolation of water-soluble mono-phosphoramidate from water-soluble urea byproducts is difficult
Solution Approach 1:
The patent extracts the harmful urea byproduct from the reaction system by utilizing its water solubility and removing it through aqueous workup, thereby separating the desired phosphoramidate product from the byproduct and simplifying purification
Solution Approach 2:
The patent creates an inert organic phase environment using dichloromethane or ethyl acetate where the phosphoramidate product resides, while the water-soluble urea byproduct remains in the aqueous phase, enabling easy phase separation and product isolation
4Reliability
If existing methods are used to prepare phosphoramidates, then the reaction can proceed, but the purification techniques damage the acid-sensitive phosphoramidate
Solution Approach 1:
The patent changes the purification parameters by using mild conditions (neutral pH, low temperature, non-aqueous solvents) that preserve the acid-sensitive phosphoramidate structure, avoiding degradation while achieving effective purification
Solution Approach 2:
The patent replaces harsh purification techniques with mild extraction and chromatography methods that do not expose the phosphoramidate to degrading conditions, thereby maintaining product integrity throughout the purification process
5Reliability
If conventional methods are used for phosphoramidate preparation, then the reaction can proceed, but the reaction efficiency varies highly and purification is time-consuming
Solution Approach 1:
The patent ensures continuous useful action by using catalysts (DMAP, NMI) that maintain high reaction rates throughout the process, and by designing a workup procedure that continuously removes byproducts, thereby reducing both reaction time and purification time while maintaining high efficiency
Solution Approach 2:
The patent segments the purification process into simple sequential steps (aqueous wash, organic extraction, concentration) that can be performed rapidly, reducing the total time required for purification while maintaining high product quality
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
This method enables the efficient and selective preparation of phosphoramidates with high yields (>60-70%) and purity, overcoming previous inefficiencies and providing a viable route for phosphoramidate-containing compounds in therapeutic applications.
Implementation Method 1
treating a compound of Formula II with a dialkylazodicarboxylate; a phosphine reagent; and an amine of Formula III in an aprotic solvent to yield a compound of Formula I
Data Source
AI summary
Provided is a method for the preparation of mono-amidated phosphates or phosphonates as well as mono-amidated phosphates and phosphonates prepared by such method.