Chroman Derivative Synthesis Using Pressurized Lewis Acid Catalysis
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Solution Overview
Problem
Current processes for manufacturing chroman derivatives such as α-tocopherol and its alkanoates face challenges in achieving high selectivities and yields, particularly in the condensation reactions involving phenols and Lewis acids under atmospheric conditions.
Innovation Solution
The process involves using a Lewis acid or a mixture of a Lewis acid with a Bronsted acid as a catalyst under pressure, preferably at an absolute pressure of at least 1.1 bar, to enhance the condensation and ring closure reactions of phenols like 2,3,5-trimethylhydroquinone with compounds like isophytol, resulting in high yields of α-tocopherol and its alkanoates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If atmospheric pressure conditions are used in the condensation reaction of phenols with Lewis acids, then the process is simpler to operate, but the selectivity and yield of chroman derivatives are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the pressure condition from atmospheric pressure to elevated pressure (1.1-20.0 bar). This parameter change directly addresses the contradiction by improving selectivity and yield (90-99% selectivity, up to 95% yield) while maintaining operational feasibility through the use of standard pressure reaction equipment.
2Ease of operation
If atmospheric pressure conditions are used in the condensation reaction of phenols with Lewis acids, then the process is simpler to operate, but the selectivity of chroman derivatives is insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the pressure condition from atmospheric pressure to elevated pressure (1.1-20.0 bar). This parameter change directly addresses the contradiction by improving selectivity (90-99% selectivity for chroman derivatives) while maintaining operational feasibility through the use of standard pressure reaction equipment.
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 selectivity and yield of chroman derivatives like α-tocopherol and its alkanoates, making the process more efficient and effective compared to traditional methods.
Implementation Method 1
at least one step of the process is carried out in the presence of a Lewis acid or a mixture of a Lewis acid with a Bronsted acid as the catalyst under pressure
Data Source
AI summary
The present invention relates to novel processes for the manufacture of chroman derivatives such as α-tocopherol (TCP) and alkanoates thereof, especially α-tocopheryl acetate (TCPA), whereby at least one step of the processes is carried out in the presence of a Lewis acid or a mixture of a Lewis acid with a Bronsted acid as the catalyst under pressure, preferably at an absolute pressure of at least 1.1 bar.As starting materials for the manufacture of TCP and its alkanoates either a mixture of 2,3,5-trimethylhydroquinone (TMHQ) or 2,3,6-trimethylhydroquinone-1-alkanoate (TMHQA) and a compound selected from the group consisting of phytol (PH), isophytol (IP) and (iso)phytol derivatives or 2-phytyl-3,5,6-trimethyl-hydroquinone (PTMHQ)/3-phytyl-2,5,6-trimethylhydroquinone-1-alkanoate (PTMHQA) and/or an isomer thereof are used.Suitable Lewis acids are indium(III) salts and scandium(III) salts. Suitable acid mixtures are iron/iron(II) chloride/hydrogen chloride and zinc(II) chloride/hydrogen chloride.