Pyrazole Carboxylic Acid Amide Acylation Yield Optimization
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Solution Overview
Problem
The yield of the acylation reaction in the preparation of 3-difluoromethyl-1-methyl-1 H-pyrazole-4-carboxylic acid (9-dichloromethylene-1,2,3,4-tetrahydro-1,4-methanonaphthalen-5-yl)-amide is not optimized, leading to inefficiencies in the production process.
Innovation Solution
Selecting a specific acylating agent of the formula R 1 -C(X)-Cl, where X is oxygen or sulfur, and R 1 is chloro, alkoxy, CH 3 -C(=CH 2 )-O-, phenoxy, or trichloromethoxy, for acylating the oxime oxygen of the compound, followed by reaction with the compound of formula IX in the presence of an acid, significantly improves the yield by reducing reaction time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional acylating agents are used in the acylation reaction, then the reaction can proceed, but the yield is not optimized and reaction time is extended
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of the acylating agent. Specifically, it uses acylating agents with electron-withdrawing groups (such as trifluoroacetyl, dichloroacetyl, or fluoroacetyl groups) instead of conventional acylating agents. This structural parameter change increases the reactivity of the acylating agent, thereby improving the yield of the acylation reaction and reducing the reaction time required to achieve optimal conversion.
2Productivity
If conventional acylating agents are used, then the process is simple, but the production efficiency is low
Solution Approach 1:
The patent modifies the chemical parameters of the acylating agent by incorporating electron-withdrawing groups, which enhances reaction efficiency and production output. Although this represents a change in chemical parameters rather than physical device complexity, it maintains process simplicity while significantly improving production efficiency through enhanced reactivity and yield.
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 enhances the yield of the desired compound by accelerating the formation and reducing reaction time, making the production more efficient.
Implementation Method 1
acylating the oxime oxygen of the compound of formula VIII in the presence of a solvent and an acylating agent of formula XI
Implementation Method 2
reacting the so obtained product of formula XII with the compound of formula IX
Data Source
AI summary
The invention relates to a process for the preparation of 3-difluoromethyl-1 -methyl-1 H-pyrazole-4-carboxylic acid (9-dichloromethylene-1,2,3,4-tetrahydro-1,4-methano-naphthalen-5-yl)-amide by acylating the oxime oxygen of the compound of formula (VIII), in the presence of a solvent and an acylating agent of formula (XI) R1C(X)-CI (XI); wherein X is oxygen or sulfur; R1 is chloro if X is oxygen or sulfur; or R1 is C1-C6alkoxy, CH3-C(=CH2)-0-, phenoxy or trichloromethoxy if X is oxygen; and a) if R1 is chloro and the compound of formula (XI) was added to the compound of formula (VIII); reacting the so obtained product of formula (Xlla) wherein X is oxygen or sulfur; with the compound of formula (IX) b) if R1 is chloro and the compound of formula (VIII) was added to the compound of formula (XI); or R1 is C1-C6alkoxy, CH3-C(=CH2)-0-, phenoxy or trichloromethoxy if X is oxygen; reacting the so obtained product of formula (XII) wherein X is oxygen or sulfur; R1 is chloro if X is oxygen or sulfur; or R1 is C1-C6alkoxy, CH3-C(=CH2)-0-, phenoxy or trichloromethoxy if X is oxygen; with the compound of formula (IX).