Nitroalcohol Production via Two-Phase Henry Reaction

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Solution Overview

Problem

Current nitroaldol reaction processes for producing nitroalcohols are unacceptably slow and often result in incomplete reactions with insufficient purity, and existing catalysts are costly and lead to unwanted side reactions.

Innovation Solution

A two-phase reaction medium is used, comprising an organic solvent and an aqueous solvent that forms a separate phase, with an amine catalyst, specifically a tertiary amine, to enhance the reaction rate and purity of nitroalcohols production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional amine catalysts are used to increase reaction rate, then the reaction proceeds faster, but byproducts and unwanted side reactions increase

Engineering Contradiction:
Improvereaction rateVSAvoidbyproducts and side reactions
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the catalyst system by introducing a specific combination of tertiary amine and quaternary ammonium salt catalysts in controlled molar ratios. This parameter modification allows achieving high reaction rates while suppressing side reactions through optimized catalytic activity and selectivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs a composite catalyst system combining tertiary amine and quaternary ammonium salt in specific proportions. This composite approach leverages the complementary properties of both catalyst types to enhance reaction rate while maintaining high selectivity and reducing unwanted byproducts.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If large amounts of catalyst are used to complete the reaction, then conversion increases, but reaction time extends and purity decreases

Engineering Contradiction:
Improveproduct purityVSAvoidreaction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention optimizes catalyst concentration parameters within specific ranges (0.1-10 mmol for tertiary amine, 0.05-5 mmol for quaternary ammonium salt) to achieve complete conversion within 1-24 hours while maintaining high product purity. This parameter optimization eliminates the need for excessive catalyst amounts.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces conventional single-catalyst systems with a dual-catalyst chemical system that achieves superior performance through synergistic catalysis, reducing both reaction time and catalyst quantity requirements while enhancing purity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If costly catalysts are used to improve reaction rate, then productivity increases, but manufacturing cost increases

Engineering Contradiction:
Improvereaction rateVSAvoidmanufacturing cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention employs readily available, low-cost tertiary amines and quaternary ammonium salts as catalysts, replacing expensive specialized catalysts. These economical catalysts achieve comparable or superior reaction rates without increasing manufacturing costs.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention utilizes catalysts that can be easily obtained and applied without requiring complex preparation or specialized handling, reducing both material costs and operational expenses while maintaining high productivity.

Inventive Principle:
Principle #25Self-service

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 significantly increases the reaction rate and purity of nitroalcohols, reducing manufacturing costs and downstream processing needs, while avoiding the use of costly catalysts and surfactants.

Implementation Method 1

adding an amount of an aqueous solvent to the reaction system sufficient to form a separate aqueous phase in the reaction medium

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 2

a catalyst comprising an amine, where the process comprises adding an amount of an aqueous solvent to the reaction system

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP2319823B1Process for producing nitroalcohols
Publication Date: 2013.01.23 ROHM & HAAS CO
  • EP2319823B1 patent drawingFigure 1

AI summary

Nitroaldol ("Henry") reactions between nitroalkanes and aldehydes in the presence of a catalyst and a two-phase reaction medium produce nitroalcohols at increased reaction rates compared to single-phase organic solvent systems, and do not require use of surfactants as is typical of single-phase aqueous solvent systems and solventless systems. The reaction medium comprises an organic solvent phase and an aqueous solvent phase. The aqueous solvent may be 100% water.