Carboxylic Acid Halide Stabilization via Solvation
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Solution Overview
Problem
Conventional methods for producing carboxylic acid halides with a (meth)acryloyl group result in low purity due to side reactions and instability during storage, requiring additional steps to purify and stabilize the compounds.
Innovation Solution
Incorporating a specific amount of a nitrogen atom-containing polar aprotic solvent in the reaction system and storage solutions to inhibit halogen atom addition reactions, thereby maintaining high purity and stability of the carboxylic acid halides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a carboxylic acid having a (meth)acryloyl group is reacted with a halogenating agent, then the target carboxylic acid halide is produced, but halogen atom addition at the double bond of the (meth)acryloyl group occurs as a side reaction, reducing product purity
Solution Approach 1:
A nitrogen-containing polar aprotic solvent is introduced as an intermediary substance in the reaction system. This solvent mediates the reaction between carboxylic acid and halogenating agent, suppressing the harmful halogen atom addition side reaction while allowing the desired esterification reaction to proceed, thereby producing high-purity carboxylic acid halide.
Solution Approach 2:
The invention changes the reaction parameters by selecting specific nitrogen-containing polar aprotic solvents (such as N,N-dimethylformamide, N-methyl-2-pyrrolidone, or hexamethylphosphoric triamide) and controlling their amount relative to the carboxylic acid (0.5-10 equivalents). This parameter optimization suppresses side reactions and enhances product purity.
2Manufacturing precision
If additional steps are taken to convert halogenated by-products back to (meth)acrylates, then purity is improved, but the production process becomes more complicated
Solution Approach 1:
The invention extracts or eliminates the need for additional purification steps by preventing the formation of halogenated by-products in the first place through the use of nitrogen-containing polar aprotic solvents. This approach removes the complexity of converting by-products back to desired compounds.
Solution Approach 2:
The nitrogen-containing polar aprotic solvent is added at the beginning of the reaction to prevent side reactions before they occur. This preliminary action avoids the formation of halogenated by-products, eliminating the need for subsequent conversion steps and simplifying the overall process.
3Stability of the object's composition
If carboxylic acid halide is stored without stabilization, then storage is simple, but the carboxylic acid halide gradually converts to halogenated by-product, reducing purity
Solution Approach 1:
The nitrogen-containing polar aprotic solvent acts as a stabilizing intermediary during storage. It prevents the gradual conversion of carboxylic acid halide to halogenated by-products by maintaining a chemical environment that suppresses side reactions, thereby preserving product purity during storage.
Solution Approach 2:
The stabilizing solvent is incorporated into the reaction mixture before storage, performing preliminary protection against degradation. This preliminary action ensures the carboxylic acid halide remains stable and pure during storage without requiring additional stabilization steps.
4Productivity
If conventional methods are used for producing carboxylic acid halide, then production can proceed, but additional purification steps are required, reducing productivity
Solution Approach 1:
The invention segments the production process by integrating the stabilization function into the reaction step itself. The nitrogen-containing polar aprotic solvent simultaneously serves as both reaction medium and stabilizer, eliminating the need for separate purification and stabilization steps, thereby improving productivity.
Solution Approach 2:
The nitrogen-containing polar aprotic solvent performs multiple functions: it acts as the reaction medium, suppresses side reactions during esterification, and stabilizes the carboxylic acid halide during storage. This multi-functionality reduces the number of required steps and improves overall production efficiency.
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-purity production and long-term stability of carboxylic acid halides, suitable for use in liquid-crystal materials and electron transport materials without the need for additional purification steps.
Implementation Method 1
a halogen atom addition reaction at a double bond of the (meth)acryloyl group can be inhibited by providing a specific amount of a nitrogen atom-containing polar aprotic solvent in the reaction system
Implementation Method 2
when a specific amount of a nitrogen atom-containing polar aprotic solvent is provided in an organic solvent solution containing the target carboxylic acid halide, conversion of the carboxylic acid halide to a halogenated by-product in the organic solvent solution can be inhibited
Data Source
Figure 1
AI summary
Provided are a production method for compound (II) including reacting compound (I) with a halogenating agent in the presence of at least 0.5 equivalents, relative to compound (I), of a nitrogen atom-containing polar aprotic solvent; a composition containing compound (II), a halogenating agent or the like, and at least 0.5 equivalents, relative to compound (II), of a nitrogen atom-containing polar aprotic solvent; a stabilization method for compound (II); and compound (II). Accordingly, a method for producing compound (II) with high purity in an industrially advantageous manner, a composition in which this production intermediate is stabilized, and a stabilization method for compound (II) are provided. R represents a hydrogen atom or a methyl group, Y1 and Y2 each represent a chemical single bond, -O-, -O-C(=O)-, -C(=O)-O-, or the like, G1 represents a divalent chain aliphatic group having a carbon number of 1-20 or the like, A1 and A2 each represent a divalent aromatic hydrocarbon group having a carbon number of 3-12, a divalent alicyclic hydrocarbon group having a carbon number of 3-12, or the like, n represents 0 or 1, and X represents a halogen atom.