4-(4-aminophenyl)-3-morpholinone Hydrogenation in Aliphatic Alcohols
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Solution Overview
Problem
The existing methods for preparing 4-(4-aminophenyl)-3-morpholinone suffer from low yields and complex reaction conditions, including high pressure and long reaction times, which complicate scaling up the process and result in impure products.
Innovation Solution
The reaction of 4-(4-nitrophenyl)-3-morpholinone with hydrogen in the presence of a hydrogenation catalyst, preferably palladium on activated carbon, is conducted in aliphatic alcohols like ethanol at mild temperatures and pressures, significantly reducing reaction time and improving yield and purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If catalytic hydrogenation is performed in tetrahydrofuran at 70°C and 50 bar hydrogen pressure, then the nitro group is reduced to amino group, but the reaction requires long reaction time (8 hours) and high pressure equipment complexity
Solution Approach 1:
The patent changes the hydrogen pressure parameter from 50 bar to 3-10 bar, and changes the solvent from tetrahydrofuran to ethanol or isopropanol. These parameter changes enable the reaction to proceed efficiently under milder conditions, reducing apparatus complexity while maintaining product purity through the inherent selectivity of the modified reaction system
2Manufacturing precision
If catalytic hydrogenation is performed at 70°C and 50 bar hydrogen pressure for 8 hours, then complete reduction of nitro group is achieved, but the reaction time is excessively long and energy consumption is high
Solution Approach 1:
The patent modifies multiple parameters simultaneously: lowering temperature from 70°C to 40-60°C, reducing hydrogen pressure from 50 bar to 3-10 bar, and changing the solvent system. These combined parameter changes accelerate the reaction rate and enable complete reduction within 3-6 hours at 40-60°C, significantly reducing time loss and energy consumption while maintaining high product purity
Solution Approach 2:
The patent introduces a specific solvent intermediary (ethanol or isopropanol) that facilitates the hydrogenation reaction under milder conditions. This solvent mediator enables efficient hydrogen transfer and catalyst performance at lower temperatures and pressures, reducing reaction time and energy requirements while ensuring complete conversion to the pure amino product
3Loss of time
If the reaction is performed under mild conditions in aliphatic alcohols at 40-60°C and 3-10 bar hydrogen pressure, then reaction time is shortened to 3-6 hours, but yield and purity must be maintained at high levels
Solution Approach 1:
The patent optimizes the combination of parameters: temperature (40-60°C), pressure (3-10 bar), solvent (ethanol or isopropanol), and catalyst type. This specific parameter set creates optimal reaction conditions where the reaction proceeds rapidly with high selectivity, achieving complete conversion to the amino product within 3-6 hours while maintaining high purity through the controlled mild conditions that prevent side reactions
4Productivity
If high hydrogen pressure (50 bar) is applied to drive the hydrogenation reaction, then reaction rate increases, but apparatus complexity and safety requirements increase significantly
Solution Approach 1:
The patent reduces the hydrogen pressure parameter from 50 bar to 3-10 bar by changing the solvent system to aliphatic alcohols and optimizing the catalyst. This parameter change maintains adequate reaction rate for industrial productivity while dramatically simplifying the apparatus requirements, eliminating the need for high-pressure equipment and associated safety systems
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 results in high yields and high purity of 4-(4-aminophenyl)-3-morpholinone, facilitating its preparation on a larger scale with simplified purification and reduced apparatus complexity.
Implementation Method 1
the reaction of 4-(4-nitrophenyl)-3-morpholinone (VII) with hydrogen can be carried out in the presence of a hydrogenation catalyst, preferably palladium on activated carbon (5%)
Implementation Method 2
Catalytic hydrogenation of (VII) with hydrogen over palladium on activated carbon
Data Source
AI summary
The present invention relates to a process for preparing 4-(4-aminophenyl)-3-morpholinone by reacting 4-(4-nitrophenyl)-3-morpholinone with hydrogen in the presence of a hydrogenation catalyst, characterized in that the reaction is effected in an aliphatic alcohol.