Solid Base Catalyst for 4-ADPA Synthesis

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Solution Overview

Problem

Current processes for producing 4-Aminodiphenylamine (4-ADPA) require large amounts of organic base catalysts that are difficult to recycle, lead to energy-intensive steps, and result in unstable reaction conditions due to catalyst decomposition, impurities, and high solvent usage, making the process inefficient and costly.

Innovation Solution

A solid base catalyst system comprising a carrier loaded with both organic and inorganic bases, where the organic base catalyzes condensation reactions and the inorganic base regenerates the catalyst in situ, eliminating the need for separate recycling steps and allowing for higher catalyst activity and reduced solvent use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If water-soluble phase transfer catalysts are used in large amounts for the condensation reaction, then the catalytic activity is sufficient, but the catalyst cannot be easily separated and regenerated, leading to high energy consumption and decomposition

Engineering Contradiction:
Improvecatalytic activityVSAvoidcatalyst separation and regeneration
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies a solid support matrix (flexible shell) to immobilize the phase transfer catalyst, allowing it to be easily separated from the reaction mixture by filtration while maintaining catalytic activity. The solid support acts as a carrier that holds the catalyst in a recoverable form.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses porous solid supports (such as silica gel, activated carbon, or ion exchange resins) to load the phase transfer catalyst. The porous structure provides large surface area for catalyst immobilization while allowing reactants and products to diffuse freely, maintaining high catalytic activity and enabling easy separation.

Inventive Principle:
Principle #31Porous materials

2Loss of time

If the catalyst is concentrated from the aqueous phase to enable recycling, then catalyst reuse is possible, but additional energy is consumed for concentration

Engineering Contradiction:
Improvecatalyst recycling timeVSAvoidenergy for concentration
Core Design Contradiction:
Loss of timeVSUse of energy by moving object

Solution Approach 1:

The patent extracts the catalyst from the aqueous phase by adsorbing it onto a solid support material. This extraction step allows the catalyst to be removed from the solution in a concentrated form on the solid support, enabling easy separation without requiring energy-intensive evaporation or concentration of the aqueous phase.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If the condensation catalyst is present during hydrogenation, then the one-pot process is simplified, but the catalyst decomposes under hydrogenation conditions

Engineering Contradiction:
Improveprocess simplificationVSAvoidcatalyst stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The solid support matrix provides a protective environment for the phase transfer catalyst during hydrogenation. The immobilized catalyst on the solid support shows improved stability under hydrogenation conditions compared to free catalyst in solution, allowing it to withstand the more vigorous hydrogenation process without decomposing.

Inventive Principle:
Principle #30Flexible shells and thin films

4Stability of the object's composition

If low temperature hydrogenation is used to prevent catalyst decomposition, then catalyst stability is maintained, but reaction speed decreases

Engineering Contradiction:
Improvecatalyst stabilityVSAvoidreaction speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent changes the physical state of the phase transfer catalyst from dissolved to immobilized on solid support. This parameter change allows the hydrogenation to proceed at higher temperatures with improved catalyst stability, thereby increasing reaction speed while maintaining catalyst integrity.

Inventive Principle:
Principle #35Parameter changes

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 enables efficient, predictable, and faster production of 4-ADPA with reduced catalyst usage, lower energy consumption, and minimized environmental impact by allowing continuous regeneration and reuse of the catalyst, reducing waste and impurities, and enabling broader temperature ranges for hydrogenation reactions.

Implementation Method 1

aniline and nitrobenzene are condensed in the presence of the solid base catalyst to produce 4-nitrosodiphenylamine and 4-nitrodiphenylamine

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

4-nitrosodiphenylamine and 4-nitrodiphenylamine which are then hydrogenated to produce 4-aminodiphenylamine

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Data Source

PatentEP2578313B1Solid base catalyst
Publication Date: 2019.07.31 SENNICS CO LTD

AI summary

The application relates to a solid base catalyst having a carrier, an organic base, and an inorganic base. Both of the organic base and inorganic base are loaded on the carrier. The solid base catalyst is especially suitable for the synthesis of 4-Aminodiphenylamine (4-ADPA).