Sulfur-Containing Ester Synthesis via Acid Catalysis
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Solution Overview
Problem
Conventional methods for producing sulfur-containing carboxylic acid esters often require high temperatures or prolonged reaction times, leading to substrate degradation and low yields.
Innovation Solution
An addition reaction of thiocarboxylic acid with α,β-unsaturated carboxylic acid ester in the presence of an acid catalyst, such as para-toluenesulfonic acid, allows for a single-step production of sulfur-containing carboxylic acid esters with improved yield and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional methods (high temperature or prolonged reaction time) are used to produce sulfur-containing carboxylic acid esters, then the reaction can proceed to completion, but substrate degradation occurs and yield decreases
Solution Approach 1:
The patent changes the reaction parameters by introducing an acid catalyst (such as p-toluenesulfonic acid) which enables the reaction to proceed rapidly at lower temperatures (reflux conditions) without requiring prolonged heating times. This parameter change resolves the contradiction by achieving both high reaction speed and high yield (85-95%) simultaneously, avoiding substrate degradation that occurs in conventional methods
Solution Approach 2:
The acid catalyst acts as an intermediary substance that facilitates the addition reaction between thiocarboxylic acid and α,β-unsaturated carboxylic acid ester. The catalyst enables the reaction to proceed under milder conditions with shorter time, thereby maintaining high yield while improving productivity. The catalyst is used in small amounts (0.01-0.1 equivalents) and can be easily removed after reaction
2Ease of manufacture
If conventional methods are used, then the reaction can be performed without special catalysts, but the reaction time is prolonged and substrate degradation occurs
Solution Approach 1:
The introduction of acid catalyst changes the reaction kinetics parameters, enabling the reaction to complete in hours rather than days. The catalyst lowers the activation energy barrier, allowing the reaction to proceed rapidly under reflux conditions without requiring extended reaction times or complex multi-step procedures
Solution Approach 2:
The acid catalyst serves as a simple intermediary that dramatically accelerates the reaction without complicating the overall process. Common catalysts like p-toluenesulfonic acid are easily handled and removed, maintaining ease of manufacture while reducing reaction time from 36 hours to typically 2-24 hours depending on conditions
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 method enables the quick and high-yield production of sulfur-containing carboxylic acid esters with excellent aroma, suitable for aromatized and flavored products, achieving good yield and purity.
Implementation Method 1
an addition reaction of a thiocarboxylic acid (2) with an α,β-unsaturated carboxylic acid ester (1) in the presence of an acid catalyst gives a sulfur-containing carboxylic acid ester (3)
Data Source
AI summary
The present invention provides a method for producing sulfur-containing carboxylic acid esters that are useful for aromatizing and flavoring purpose and can cater to the needs for diversified aromatized and/or flavored products, and to further provide a fragrance and/or flavor composition comprising the ester producible by the method and an aromatized and/or flavored product comprising the same.The sulfur-containing carboxylic acid ester is represented by the following formula (3):wherein R1 represents an alkyl group having 1 to 10 carbon atoms or an optionally substituted phenyl group (wherein the substituent thereof is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms), R2 and R3 independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, or R2 and R3 together form an alkylene group, and R4 represents an alkyl group having 1 to 4 carbon atoms.