Furanic Diels-Alder Route to Phthalic Anhydride
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Solution Overview
Problem
Current bio-based routes for producing phthalic anhydride from furanic compounds suffer from poor atom economy, scalability issues, and require expensive, difficult-to-recycle reagents, resulting in low yields.
Innovation Solution
A method involving the reaction of furfuryl alcohol or its analogues with a dienophile containing an α,β-unsaturated carbonyl group, using a specific leaving group and base, to form a phthalide compound through a Diels-Alder reaction, which can then be ring-opened and aromatized to produce phthalic anhydride in a more efficient and scalable manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the Diels-Alder reaction of furan with maleic anhydride is used to produce phthalic anhydride, then a bio-based route is achieved, but poor atom economy and low yield result due to complex mixtures and difficult-to-recycle reagents
Solution Approach 1:
The patent changes the chemical parameters by using furfuryl alcohol instead of furan, and employing an α,β-unsaturated carbonyl compound with an α'-leaving group instead of maleic anhydride. This parameter change transforms the reaction pathway to produce predominantly a single phthalide compound rather than complex mixtures, thereby improving both atom economy and yield
Solution Approach 2:
The invention replaces expensive and difficult-to-recycle reagents (methanesulfonic acid and acetic anhydride) with simpler, more economical reagents that are easier to handle and recycle. This substitution maintains reaction effectiveness while improving economic viability and reducing waste disposal costs
2Quantity of substance
If furan is used with maleic anhydride in Diels-Alder reaction, then phthalic anhydride can be produced, but complex mixtures of regio- and stereoisomers are formed requiring expensive and difficult-to-recycle reagents
Solution Approach 1:
By changing the substrate from furan to furfuryl alcohol and the dienophile to an α,β-unsaturated carbonyl compound with an α'-leaving group, the reaction parameters are optimized to produce predominantly a single phthalide compound. This parameter change eliminates the formation of complex regio- and stereoisomer mixtures that plague the traditional furan-maleic anhydride route
Solution Approach 2:
The α'-leaving group acts as an intermediary that facilitates selective reaction pathways. Its presence enables the formation of a single predominant product by controlling the reaction mechanism, thereby preventing the formation of complex isomeric mixtures
3Ease of manufacture
If the traditional route using methanesulfonic acid and acetic anhydride is employed, then ring-opening and dehydration can be achieved, but processability and scalability are prohibited
Solution Approach 1:
The invention replaces expensive and difficult-to-recycle reagents (methanesulfonic acid and acetic anhydride) with simpler, more economical reagents that are easier to handle and recycle. This substitution maintains reaction effectiveness while improving economic viability and reducing waste disposal costs
Solution Approach 2:
By changing the reaction parameters to use furfuryl alcohol and an α,β-unsaturated carbonyl compound with an α'-leaving group, the process produces predominantly a single phthalide compound. This simplifies downstream processing and enables scalable production by eliminating the need for complex separation and purification steps
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 allows for the predominant formation of a single phthalide compound, improving yield and scalability while avoiding the use of expensive and hard-to-recycle reagents, thus enhancing the atom economy of the process.
Implementation Method 1
the production of renewable aromatics from furanics by a cyclo-addition or Diels-Alder reaction with dienophiles
Data Source
AI summary
The present invention is directed to the preparation of phthalic anhydride compounds and the intermediate phthalide compounds. In particular, the invention is directed to an improved bio-based route from furanic compounds to phthalic anhydride compounds by reacting furfuryl alcohol (i.e. 2-hydroxymethylfuran) or an analogue thereof having a nucleophilic atom on the 2-methyl, with a dienophile comprising an α,β-unsaturated carbonyl comprising an α′-leaving group. The inventions further involved preparation of phthalic anhydride compounds, phthalic acid compounds and reduction products of the intermediate phthalide compounds.