Nerol Synthesis via Tertiary Amine Hydrogenation
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Solution Overview
Problem
Current catalytic hydrogenation processes for converting α,β-unsaturated carbonyl compounds like citral to nerol or geraniol suffer from low selectivity and incomplete conversion, resulting in high levels of unwanted side products and impurities, making it difficult to obtain pure nerol due to the formation of mixtures with geraniol and other by-products.
Innovation Solution
A process involving a hydrogenation of unsaturated aldehydes in the presence of a catalyst and a tertiary amine, where the tertiary amine is used in a controlled amount to achieve high selectivity and conversion rates, using a heterogeneous catalyst such as a supported ruthenium-iron catalyst on an inert support material, allowing for the production of nerol or geraniol with high purity and reduced side products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional catalytic hydrogenation is used to convert citral to nerol, then the reaction proceeds with high conversion rate, but the selectivity is insufficient leading to high levels of unwanted side products
Solution Approach 1:
The patent modifies reaction parameters by introducing a tertiary amine additive and optimizing hydrogenation conditions to enhance selectivity toward nerol while suppressing side reactions such as over-hydrogenation and isomerization that produce unwanted by-products
Solution Approach 2:
A tertiary amine is introduced as an intermediary substance that mediates the hydrogenation reaction, improving selectivity by facilitating the desired transformation while minimizing the formation of side products through its interaction with the catalyst and reactants
2Productivity
If hydrogenation is carried out to high conversion to reduce unreacted educt, then the yield increases but side products from over-hydrogenation increase
Solution Approach 1:
The reaction system incorporates feedback control through the tertiary amine additive, which modulates catalyst activity to maintain high conversion while preventing over-hydrogenation by regulating the hydrogenation rate as the reaction progresses
Solution Approach 2:
Optimization of reaction parameters including the addition of tertiary amine and control of hydrogenation conditions enables the system to achieve high conversion rates while suppressing over-hydrogenation side reactions through enhanced selectivity
3Adaptability or versatility
If the reaction produces mixtures of nerol and geraniol, then the product diversity increases, but the purity of nerol decreases making separation difficult
Solution Approach 1:
By adjusting reaction parameters and introducing tertiary amine, the patent enhances the selectivity for nerol formation over geraniol, thereby improving nerol purity in the product mixture and facilitating easier separation by rectification
4Object-generated harmful factors
If side products with boiling points equal to nerol are formed, then the reaction complexity increases, but the ease of separation by rectification decreases
Solution Approach 1:
The patent modifies reaction conditions and introduces tertiary amine to minimize the formation of side products with boiling points similar to nerol, thereby simplifying the rectification process and improving the ease of obtaining pure nerol through distillation
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 achieves high yields of nerol or geraniol with low levels of side products, enabling efficient and economical production by maintaining catalyst activity over multiple use cycles and achieving nerol purity above 90% through rectification, suitable for industrial-scale production.
Implementation Method 1
A process involving a hydrogenation of unsaturated aldehydes in the presence of a catalyst and a tertiary amine
Implementation Method 2
hydrogenation of unsaturated aldehydes in the presence of a catalyst and a tertiary amine
Implementation Method 3
using a heterogeneous catalyst such as a supported ruthenium-iron catalyst on an inert support material
Data Source
AI summary
The present invention provides a process for preparing an unsaturated alcohol of the formula (I), wherein one of R1 and R2 is preferably C2-C10-alkyl or C2-C10-alkenyl containing one double bond and the other one is preferably hydrogen or methyl; R3 is preferably hydrogen; which comprises subjecting an educt composition including at least 75% by weight of an unsaturated aldehyde of the formula (II) wherein R1, R2 and R3 preferably have the above defined meanings, to a hydrogenation in the presence of a catalyst and a tertiary amine; wherein the tertiary amine is used in an amount ranging from 0.001 to 0.7% by weight, based on the total amount of the liquid reaction mixture. The invention further relates to the nerol compound obtainable by the inventive process, to a fragrance or aroma substance composition comprising the nerol compound obtainable by the inventive process, to a method for imparting and/or intensifying an odor or flavor of a product, and also to perfumed or aromatized products comprising a nerol compound obtainable by the inventive process.