2,4-Dialkylbenzaldehyde Formylation with BF3 Ratio Control
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Solution Overview
Problem
Existing methods for producing 2,4-dialkylbenzaldehyde suffer from low conversion rates, yields, and regioselectivity in formylation reactions, particularly when using carbon monoxide with specific m-dialkylbenzene as a starting material.
Innovation Solution
A method involving the reaction of carbon monoxide with a starting material containing m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride, with controlled molar ratios of boron trifluoride and specific reaction conditions, to achieve high regioselectivity and yield of 2,4-dialkylbenzaldehyde.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carbon monoxide reacts with m-dialkylbenzene using conventional methods (PTL 1), then formylation occurs, but the conversion rate and yield are low
Solution Approach 1:
The patent changes the chemical parameters by introducing boron trifluoride as a catalyst and controlling its molar ratio (0.7-3.0 mol relative to m-dialkylbenzene). This parameter change transforms the reaction system to achieve high conversion rates and yields, resolving the contradiction between productivity and reliability in formylation.
Solution Approach 2:
Boron trifluoride acts as an intermediary substance that facilitates the formylation reaction between carbon monoxide and m-dialkylbenzene. This mediator enables the reaction to proceed with high efficiency, solving the problem of low conversion and yield in conventional direct formylation methods.
2Productivity
If formylation is performed on m-dialkylbenzene, then 2,4-dialkylbenzaldehyde is produced, but regioselectivity is poor with multiple isomers formed
Solution Approach 1:
The patent achieves high regioselectivity by changing the reaction parameters, specifically the molar ratio of boron trifluoride (0.7-3.0 mol) and reaction temperature (-40°C to 10°C). These parameter changes direct the formylation to occur preferentially at the desired position, producing 2,4-dialkylbenzaldehyde with 80 mol% or higher content while maintaining high productivity.
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 method provides 2,4-dialkylbenzaldehyde with excellent conversion rate, yield, and regioselectivity, overcoming the limitations of previous methods by using specific m-dialkylbenzene and controlling reaction parameters.
Implementation Method 1
allowing carbon monoxide to react on a starting material containing m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride for formylation
Implementation Method 2
allowing carbon monoxide to react on a starting material containing m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride
Data Source
AI summary
An object of the present invention is to provide a method for producing 2,4-dialkylbenzaldehyde with excellent conversion rate and yield, and excellent regioselectivity for formylation, by allowing carbon monoxide to react on a starting material containing a specific m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride. The method for producing 2,4-dialkylbenzaldehyde according to the present invention comprises a step of allowing carbon monoxide to react on a starting material containing m-dialkylbenzene represented by formula (1) in the presence of hydrogen fluoride and boron trifluoride for formylation at least at a position (a), wherein the starting material is a dialkylbenzene containing more than 90 mol% of m-dialkylbenzene represented by formula (1), and the number of moles of boron trifluoride relative to 1 mole of m-dialkylbenzene represented by formula (1) is 0.7 mol or more and 3.0 mol or less: wherein R1 represents an alkyl group having 1 or more and 3 or less carbon atoms, and R2 represents a chain or cyclic alkyl group having 2 or more and 7 or less carbon atoms, with a secondary or tertiary carbon at the benzylic position, provided that the number of carbons of R2 is larger than the number of carbons of R1.