Anthranilic Diamide Synthesis via Halogenation and Hydrazine Condensation
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Solution Overview
Problem
Existing methods for synthesizing anthranilic diamides face challenges such as poor yields, economically unviable processes, and extreme reaction conditions, making them unsuitable for commercial scale production.
Innovation Solution
A novel process involving the reaction of specific compounds to form anthranilic diamides, where a compound of formula III is obtained by halogenating a compound of formula VI, which is derived from reacting compounds of formulas VII and VIII, and subsequently reacting with a hydrazine compound to achieve high yields and economic viability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DIBAL or LiAlH4 is used to prepare tetrazolyl substituted N-(aryl or heteroaryl) pyrazole-5-carboxylic acid, then the synthesis can be achieved, but very low temperature conditions are required and the process becomes uneconomical
Solution Approach 1:
The patent replaces expensive reagents (DIBAL, LiAlH4) with cheaper alternatives (sodium borohydride, formic acid) that can be used under milder, more economical conditions. This substitution directly addresses the economic viability issue while maintaining synthesis effectiveness.
Solution Approach 2:
The patent changes the reaction parameters from very low temperature conditions to ambient or mildly elevated temperatures. This parameter change eliminates the need for expensive low-temperature equipment and operations while achieving the same synthetic transformation.
2Productivity
If trihalo substituted acetylene ketones are used to produce 1-pyridinylpyrazole-5-carboxylic acids or esters, then the reaction can proceed, but the starting materials are expensive making the process economically unviable
Solution Approach 1:
The patent substitutes expensive trihalo substituted acetylene ketones with cheaper starting materials (β-keto esters, hydrazines) that are readily available and economically viable for commercial production, while maintaining the ability to produce the desired pyrazole carboxylic acids or esters.
3Productivity
If 1,3-dicarbonyls or 1,3-bis-electrophilic compounds react with hydrazines to form pyrazoles, then pyrazole formation occurs, but the product consists of a mixture of regioisomeric pyrazoles reducing selectivity
Solution Approach 1:
The patent introduces specific structural features at particular positions of the starting materials (electron-withdrawing groups at α-position, specific substitution patterns) to create local electronic differences that direct the hydrazine attack to a specific position, thereby achieving high regioselectivity in pyrazole formation.
Solution Approach 2:
The patent employs asymmetric substitution patterns in the starting materials where one side of the 1,3-dicarbonyl system is electronically distinct from the other, creating an asymmetric environment that favors formation of one regioisomer over the other during cyclization with hydrazine.
4Reliability
If existing processes are used to prepare anthranilic diamides, then synthesis can be achieved, but poor yields and extreme reaction conditions make them unsuitable for commercial scale production
Solution Approach 1:
The patent modifies reaction parameters to use milder conditions (ambient temperature, atmospheric pressure, aqueous or alcoholic solvents) compared to extreme conditions in prior art. This enables commercial-scale production with standard equipment and improved safety while maintaining high yields.
Solution Approach 2:
The patent employs inexpensive, readily available reagents and catalysts that can be handled under mild conditions, eliminating the need for specialized equipment and complex purification procedures, thereby enabling economical commercial-scale production.
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 process provides a high-yielding and economically attractive method for preparing anthranilic diamides, overcoming the shortcomings of previous methods by offering improved selectivity and scalability.
Implementation Method 1
a compound of formula V is obtained from a compound of formula VI
Implementation Method 2
the compound of formula III is reacted with a hydrazine compound to obtain a compound of formula I
Data Source
AI summary
The present invention relates to a novel process for preparing compounds of formula I; (I) from compounds of formula III or compounds of formula XII which in turn are obtained by a novel process according to the present invention, (III) (XII) wherein, R2, R3, R4, R8, m, n, p, A, Q, T, W1, LG1 and LG2 are each as defined in the description.