Propanil Crystalline Modification for Weed Control
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Solution Overview
Problem
Current methods for producing propanil, a widely used herbicide, do not effectively characterize or utilize its different crystalline forms, leading to inefficient weed control and environmental concerns due to high dosage requirements.
Innovation Solution
A crystalline modification of propanil is developed using a process involving halogenated hydrocarbon solvents, which enhances bioefficacy and allows for reduced dosage, combined with agrochemically acceptable excipients and other pesticides, improving weed control efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional recrystallization methods are used to produce propanil, then the manufacturing process is simple, but the bioefficacy is insufficient and high dosage is required
Solution Approach 1:
The patent applies parameter changes by modifying the crystallization conditions (solvent type, temperature, pH) to obtain a specific crystalline form of propanil with enhanced bioefficacy. The use of acetone as a recrystallization solvent and controlled cooling rates produces crystals with improved biological activity, allowing reduced dosage while maintaining effectiveness.
Solution Approach 2:
The patent utilizes phase transitions during the recrystallization process to obtain a specific crystalline modification of propanil. By controlling the melting and crystallization phases under specific conditions (temperature ranges, solvent selection), the patent produces a crystalline form with superior bioefficacy properties compared to conventional forms.
2Reliability
If high dosage of propanil is applied for effective weed control, then weed control efficacy is achieved, but environmental impact increases
Solution Approach 1:
By changing the crystallization parameters to produce a specific crystalline form of propanil, the patent achieves enhanced bioefficacy. This allows effective weed control at lower dosages, thereby reducing environmental impact and harmful effects while maintaining the desired weed control efficacy.
3Reliability
If different crystalline forms of propanil are not characterized, then the manufacturing process is straightforward, but the bioefficacy potential is not optimized
Solution Approach 1:
The patent replaces complex mechanical characterization methods with simpler analytical techniques. By using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) to characterize the crystalline forms, the patent achieves detailed understanding of bioefficacy-related properties without requiring complex mechanical testing equipment or procedures.
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 crystalline modification of propanil achieves better bioefficacy in controlling weeds at lower application rates, reducing environmental impact and extending the use of the herbicide effectively.
Implementation Method 1
crystallization of propanil from chloroform/hexane
Implementation Method 2
crystallization of propanil from benzene
Data Source
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AI summary
The present invention relates to crystalline modification of (3,4- dichlorophenyl)propanamide (propanil), to a process for the preparation of the same, to pesticidal mixtures and compositions comprising the crystalline modification of 5 (3,4-dichlorophenyl)propanamide and to a method of combating weeds using said mixtures and compositions.