Azoxystrobin Synthesis via Trimethylamine Catalyst Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for synthesizing azoxystrobin face challenges such as catalyst recycling difficulties, high costs, and cumbersome industrial processes, including high nitrogen and COD in wastewater, low yields, and complex post-processing operations.
Innovation Solution
A method using trimethylamine as a catalyst for reacting 2-cyanophenol or its salt with a compound represented by formula I, allowing for high-yield azoxystrobin production with catalyst recycling and simplified post-processing, reducing costs and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If DABCO catalyst is used in polar aprotic solvent DMF, then reaction yield reaches 98.7%, but catalyst cannot be recycled and wastewater contains high total nitrogen and COD
Solution Approach 1:
The patent changes the solvent parameter from polar aprotic (DMF) to non-polar (toluene), which fundamentally alters the catalyst's solubility behavior. This parameter change enables catalyst recovery while maintaining high reaction yield, resolving the contradiction between productivity and environmental harm.
Solution Approach 2:
The patent implements catalyst recovery by exploiting the catalyst's insolubility in non-polar solvents. The catalyst can be filtered and reused multiple times, transforming a disposable catalyst system into a recoverable one, thereby eliminating wastewater contamination while maintaining productivity.
2Productivity
If DABCO catalyst is used with high boiling point, then reaction proceeds efficiently, but catalyst recycling becomes difficult due to high boiling point
Solution Approach 1:
The patent extracts the catalyst from the reaction mixture by exploiting its insolubility in non-polar toluene. The catalyst precipitates and can be easily filtered out, separating the catalyst recovery step from the reaction step and simplifying the overall operation despite the catalyst's high boiling point.
3Loss of substance
If high vacuum distillation is used to remove DMF, then solvent is removed, but workshop operation becomes difficult and post-processing becomes cumbersome
Solution Approach 1:
The patent changes the solvent parameter from high-boiling DMF to low-boiling toluene, which can be removed by simple distillation without requiring high vacuum equipment. This parameter change eliminates the need for complex post-processing operations while achieving complete solvent removal.
4Productivity
If large amount of trimethylamine is used to form quaternary ammonium salt, then reaction proceeds, but separation yield is low and two steps are needed causing cumbersome operation
Solution Approach 1:
The patent extracts the catalyst from reaction mixture by filtration, eliminating the need for complex separation steps. This simple extraction method achieves complete catalyst removal in one step, avoiding the multi-step process and low yield associated with quaternary ammonium salt formation and separation.
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 yields of azoxystrobin with catalyst recycling, significantly reducing costs and environmental pollutants, making it suitable for industrial production.
Implementation Method 1
reacting 2-cyanophenol or a salt thereof with a compound represented by formula I under the catalysis of a trimethylamine catalyst to obtain azoxystrobin
Implementation Method 2
adding water and stirring to cause stratification, to provide an organic phase containing the azoxystrobin
Implementation Method 3
The organic solvent is removed to provide solid azoxystrobin
Data Source
AI summary
The present invention provides a process for preparing azoxystrobin, which is performed by reacting 2-cyanophenol or a salt thereof with a compound represented by formula I under the catalysis of a trimethylamine catalyst to obtain the azoxystrobin represented by formula II, which allows the yield of the product azoxystrobin to reach 98% or more, the yield of separated product to reach 95% or more and the post-processing to be simple. The trimethylamine catalyst can be recycled and reused in synthesizing the target product azoxystrobin, which not only reduces the cost but also reduces the total nitrogen and COD in wastewater. The advantages regarding of cost and environmental protection of the method according to the present invention are significant and thus the method is suitable for industrial production.