Halocyclopropanation Reagent Selection for Yield and Selectivity
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Solution Overview
Problem
Existing halocyclopropanation processes are limited in their efficiency and versatility for producing molecules with pesticidal utility against pests in Phyla Arthropoda, Mollusca, and Nematoda, particularly in terms of reaction conditions and reagent selection.
Innovation Solution
The use of halocyclopropanating reagents such as carbon tetrachloride, tetrachloroethylene, chloroform, trichloroacetic acid salts, hexafluoroacetone, and hexachloroacetone, in conjunction with lithium salts of tertiary alkoxides and phase-transfer catalysts, to facilitate the halocyclopropanation of specific molecules under controlled temperature and pressure conditions, enhancing the formation of desired products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing halocyclopropanation processes are used, then the basic reaction can proceed, but the yield and selectivity are limited
Solution Approach 1:
The patent applies parameter changes by systematically optimizing reaction conditions including temperature ranges (-78°C to 25°C), pressure conditions (1-100 atm), solvent types (dichloromethane, chloroform, dichloroethylene), and base equivalents (1-10 equivalents) to achieve both high yield and selectivity in halocyclopropanation reactions
Solution Approach 2:
The patent uses phase transfer catalysts as intermediaries to facilitate the reaction between reagents in different phases, improving both yield and selectivity by enabling more efficient interaction between reactants while maintaining reaction control
2Adaptability or versatility
If existing halocyclopropanation processes are used, then the reaction can proceed, but the versatility for producing molecules with pesticidal utility is limited
Solution Approach 1:
The patent establishes a universal halocyclopropanation methodology that can produce diverse molecules with pesticidal activity against multiple pest types (arthropods, mollusks, nematodes) using a consistent set of reagents and conditions, thereby achieving both versatility and efficiency
3Productivity
If chloroform and base are used for generating dichlorocarbene, then the reaction proceeds, but the efficiency and reagent selection are limited
Solution Approach 1:
The patent expands reagent selection by introducing multiple halocyclopropanating reagents (carbon tetrachloride, tetrachloroethylene, chloroform, trichloroacetic acid salts, hexafluoroacetone, hexachloroacetone) and optimizing base selection (lithium salts of tertiary alkoxides) with varied equivalents and conditions to achieve high efficiency across different substrate types
4Manufacturing precision
If controlled temperature and pressure conditions are applied, then the desired products are enhanced, but the process complexity increases
Solution Approach 1:
The patent optimizes temperature and pressure parameters within practical ranges (temperature: -78°C to 25°C, pressure: 1-100 atm) to enhance desired product formation while maintaining manageable process complexity through systematic parameter optimization rather than overly complex control mechanisms
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 approach significantly improves the yield and selectivity of halocyclopropanation reactions, producing molecules with enhanced pesticidal properties against target pests, thereby addressing the limitations of existing methods.
Implementation Method 1
lithium salts of tertiary alkoxides and phase-transfer catalysts, to facilitate the halocyclopropanation of specific molecules
Implementation Method 2
lithium salts of tertiary alkoxides and phase-transfer catalysts, to facilitate the halocyclopropanation
Data Source
AI summary
This disclosure relates to halocyclopropanation processes useful in forming molecules having pesticidal utility against pests in Phyla Arthropoda, Mollusca, and Nematoda.