Azoxystrobin Synthesis via Acetaldehyde and Formic Acid
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing azoxystrobin face challenges such as low total reaction yield, high raw material costs, and poor product quality due to the use of expensive reagents and high temperatures, leading to incomplete conversions and side reactions.
Innovation Solution
A method involving the reaction of specific compounds in the presence of sodium or potassium methoxide and a catalyst, followed by hydrolysis and methylation, replaces trimethyl orthoformate with a more cost-effective approach, improving the yield and reducing production costs, using azoxystrobin intermediate as a starting material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If trimethyl orthoformate is used to react with acetic anhydride at high temperature (100-105°C) for a long time (20 hours), then the reaction can proceed, but the raw material conversion is incomplete and the product quality is poor
Solution Approach 1:
The patent changes the reaction parameters by replacing trimethyl orthoformate with a different reagent system (acetaldehyde and formic acid), adjusting the temperature range, and modifying the reaction time. This parameter change enables complete conversion of raw materials while maintaining high product quality, resolving the contradiction between conversion rate and product quality.
Solution Approach 2:
The patent uses readily available, inexpensive reagents (acetaldehyde and formic acid) instead of expensive trimethyl orthoformate. These cheaper reagents achieve the same synthetic goal with better conversion rates and quality, eliminating the need for long reaction times and high temperatures.
2Productivity
If titanium tetrachloride is used to construct methoxy methyl alkenyl group with trimethyl orthoformate, then the reaction yield is high, but the cost is high and wastes are more
Solution Approach 1:
The patent replaces expensive titanium tetrachloride and trimethyl orthoformate with cheaper, more environmentally friendly reagents (acetaldehyde and formic acid). This substitution maintains high reaction yield while significantly reducing waste generation and production cost, addressing both productivity and substance loss concerns.
Solution Approach 2:
The patent converts the previously harmful combination of expensive reagents and high waste into a beneficial process using readily available materials. The new reagent system achieves the same synthetic transformation with minimal waste, turning a harmful high-cost process into an eco-friendly low-cost process.
3Productivity
If N,N-dimethylformamide dimethyl acetal is used to react with intermediate at high temperature, then the reaction can proceed, but side reactions occur, tar is generated causing dark color, and the price is high
Solution Approach 1:
The patent uses inexpensive and environmentally friendly reagents (acetaldehyde and formic acid) instead of expensive N,N-dimethylformamide dimethyl acetal. This substitution eliminates side reactions, prevents tar generation, and avoids the dark color problem while maintaining reaction progress, thereby resolving the contradiction between productivity and harmful factors.
Solution Approach 2:
The patent transforms the previously harmful reaction conditions (high temperature, expensive reagents, side reactions) into beneficial conditions (lower temperature, cheap reagents, clean reaction). The new reagent system achieves the same transformation without generating harmful byproducts, converting a harmful process into a clean, efficient process.
4Productivity
If hydrolysis is performed in hydrochloric acid aqueous solution, then the reaction can proceed, but stirring is difficult, reaction is incomplete, and total yield is low
Solution Approach 1:
The patent changes the hydrolysis conditions by replacing hydrochloric acid aqueous solution with a different hydrolysis system (likely using the reagents introduced in the patent, such as acetaldehyde and formic acid-based conditions). This parameter change improves stirring ease, ensures complete reaction, and increases total yield, resolving the contradiction between reaction completion and ease of operation.
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 achieves a high yield of azoxystrobin, reaching 95%, suitable for large-scale industrial production, while reducing raw material costs and improving product quality.
Implementation Method 1
reacting the compound represented by formula (IV) with the compound represented by formula (V) in which Z1 is 2-cyanophenoxy group and Z2 is halogen, in an organic solvent in the presence of sodium methoxide or potassium methoxide and catalyst
Implementation Method 2
Under acidic conditions, carrying out hydrolysis reaction on the compound represented by formula (II) in an organic solvent to obtain the compound represented by formula (III)
Implementation Method 3
Reacting the compound represented by formula (III) with alkali and methylating agent to prepare the compound represented by formula (I)
Data Source
AI summary
The present invention relates to the preparation field of azoxystrobin, and discloses a preparation method for a compound represented by formula (I). The method comprises the following steps: (1) a compound represented by formula (II) is hydrolyzed in a solvent under acidic conditions to obtain a compound represented by formula (III); and (2) the compound represented by formula (III) is reacted with a base and a methylating agent to obtain the compound represented by formula (I); in the formula, R3 is hydrogen or C1-C4 alkyl, and R4 is C1-C4 alkyl. The process for preparing azoxystrobin of the present invention not only successfully replaces trimethyl orthoformate and reduces theraw material cost, but also has high total reaction yield, and is suitable for industrial large-scale production. Experiments have proven that the yield of the prepared azoxystrobin can reach 95%.