Anthranilamide Synthesis via Bromination and Oxidation
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Solution Overview
Problem
Existing methods for producing anthranilamide compounds with a bromine atom at the 3-position of pyrazole face safety concerns due to the use of toxic phosphorus-type chlorinating agents and require restricted conditions to achieve good yields.
Innovation Solution
A process involving the reaction of a compound with a brominating agent and subsequent oxidation to produce an anthranilamide compound, using a brominating agent and an oxidizing agent under commonly employed conditions, allowing for high yield production without the need for toxic reagents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a phosphorus-type chlorinating agent is used to produce an anthranilamide compound with a bromine atom at the 3-position of pyrazole, then the desired product can be obtained, but the process becomes unsafe due to the high toxicity of the reagent
Solution Approach 1:
The invention extracts and removes the toxic phosphorus-type chlorinating agent from the synthesis pathway. Instead, it uses a sulfonic acid ester intermediate that can be readily converted to the desired brominated product without requiring hazardous reagents, thus eliminating the safety hazard while maintaining product obtainability
Solution Approach 2:
The invention introduces a sulfonic acid ester as an intermediary compound in the synthesis pathway. This intermediate serves as a safe bridge between the starting material and the final brominated product, replacing the need for toxic phosphorus-type chlorinating agents while enabling efficient product formation
2Productivity
If a hydroxypyrazoline compound is converted to a sulfonic acid ester and then reacted with a brominating agent, then the desired product can be obtained in good yield, but the process requires restricted conditions
Solution Approach 1:
The invention changes the reaction parameters by using a sulfonic acid ester intermediate that reacts under milder and more flexible conditions with brominating agents. This allows the reaction to proceed in common solvents at moderate temperatures, eliminating the need for restricted conditions while maintaining high yields
Solution Approach 2:
The sulfonic acid ester intermediate serves as a disposable, easily prepared species that can be generated in situ and immediately reacted with the brominating agent. This transient intermediate enables high-yield product formation under flexible, commonly employed conditions without requiring complex or restricted reaction setups
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 process efficiently produces anthranilamide compounds suitable for use as pesticides, overcoming safety issues and achieving high yields under standard conditions.
Implementation Method 1
a hydroxypyrazoline compound is converted to a specific sulfonic acid ester and then reacted with a brominating agent
Implementation Method 2
A process involving the reaction of a compound with a brominating agent and subsequent oxidation to produce an anthranilamide compound
Data Source
AI summary
To provide a process for producing an anthranilamide having the 3-position of pyrazole substituted by a bromine atom, or its salt. A process for producing an anthranilamide compound represented by the formula (I) or its salt: which comprises reacting a compound represented by the formula (II): (wherein Z is 2-pyridyl, 3-pyridyl, 4-pyridyl or benzene substituted by a nitro group), with a brominating agent, to produce a compound represented by the formula (III): and further reacting the compound of the formula (III) with an oxidizing agent.