Fosaprepitant Phosphate Intermediate Synthesis via Mild Phosphorylation
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Solution Overview
Problem
Current methods for preparing fosaprepitant phosphate intermediate are complex, require strict low-temperature conditions, and have low yields, making them unsuitable for mass commercial production and environmentally friendly.
Innovation Solution
A phosphorylation reaction of aprepitant with a phosphite in the presence of a haloalkane and a base under mild conditions, using solvents like dichloromethane and polar solvents, to obtain fosaprepitant phosphate intermediate with improved yield and process simplicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aprepitant is reacted with tetrabenzyl pyrophosphite under ultra-low temperature with sodium bis-(trimethylsilyl) amide as base, then fosaprepitant phosphate intermediate can be obtained, but the reaction conditions are strict, process is complex and yield is not high
Solution Approach 1:
The patent changes the reaction parameters by using different bases (triethylamine, diisopropylethylamine, 4-dimethylaminopyridine, or inorganic bases) and solvents (dichloromethane, chloroform, tetrahydrofuran, methyl tert-butyl ether, acetonitrile) instead of the original sodium bis-(trimethylsilyl) amide and ultra-low temperature conditions. This parameter optimization simplifies the reaction conditions while maintaining high yield and reliability.
2Productivity
If DMF, sulfolane, DMSO or NMP is used as solvent with lithium hydroxide, sodium hydroxide, potassium hydroxide, DBU or DBN as base, then fosaprepitant phosphate intermediate can be prepared, but solvents with high boiling points are utilized and large amount of waste water is produced, thus the method is not environmentally friendly
Solution Approach 1:
The patent replaces high boiling point solvents (DMF, sulfolane, DMSO, NMP) with lower boiling point alternatives (dichloromethane, chloroform, tetrahydrofuran, methyl tert-butyl ether, acetonitrile) that are easier to remove and generate less environmental pollution. The base is also optimized to include organic bases with milder conditions, reducing waste water production while maintaining high productivity.
3Reliability
If current preparation methods are used for fosaprepitant phosphate intermediate, then the intermediate can be obtained, but the costs are relatively high and the process is not suitable for mass commercial production
Solution Approach 1:
The patent optimizes reaction parameters including temperature (0-30°C), molar ratios (aprepitant:phosphite:haloalkane:base = 1:1.1-1.5:2-5:1.1-1.5), and solvent selection to achieve high yield (85-95%) with simplified procedures. These parameter changes make the process more suitable for mass commercial production by reducing complexity and cost while maintaining 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
The method achieves high yield, reduces production costs, and simplifies the process, making it suitable for industrial production while being more environmentally friendly.
Implementation Method 1
a phosphorylation reaction of aprepitant (I) and a phosphite (II) occurs in a solvent under the action of a haloalkane and a base to obtain a key intermediate of fosaprepitant, which is fosaprepitant phosphate intermediate (IV)
Data Source
AI summary
Provided are a fosaprepitant phosphate intermediate (IV) preparation method, a fosaprepitant phosphate intermediate (IV-A) and a method of (AA) for preparing fosaprepitant dimeglumine by using the intermediate (IV-A). IV: R1 and R2 are independently selected from C1-C7 alkyl groups or benzyl groups; IV-A: R1 and R2 are independently selected from C1-C7 alkyl groups, and R1 and R2 are not both benzyl groups.