Pyrimidinylpyrazole Synthesis via One-Step Condensation

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Solution Overview

Problem

Current methods for producing pyrimidinylpyrazole compounds are inefficient economically and environmentally due to the use of expensive raw materials, multiple reaction steps, and organic solvents, which are environmentally burdensome.

Innovation Solution

A one-step method involving the reaction of aminoguanidine or its salt with a β-diketone compound in the absence or presence of a solvent, preferably water, using a base like metal acetates, to produce pyrimidinylpyrazole compounds efficiently and environmentally sustainably.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional methods using hydrazinylpyrimidine compounds are used, then pyrimidinylpyrazole compounds can be produced, but the production cost increases due to expensive raw materials and multiple synthesis steps

Engineering Contradiction:

Improveproduction efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The conventional multi-step synthesis is segmented into a single-step one-pot reaction where all components (aminoguanidine, β-diketone, and base) are combined simultaneously to directly produce pyrimidinylpyrazole compounds, eliminating intermediate purification steps and reducing overall manufacturing cost

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reaction parameters are optimized by using readily available aminoguanidine and β-diketone compounds with specific molecular weights and structures, along with appropriate base catalysts, to achieve high yields while maintaining low raw material costs and simplifying the manufacturing process

Inventive Principle:

Principle #35Parameter changes

2Reliability

If organic solvents are used in the reaction, then the reaction can proceed smoothly, but the environmental burden increases

Engineering Contradiction:

Improvereaction efficiencyVSAvoidenvironmental impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potential harm of solvent-free conditions (which might lead to poor reaction efficiency) into a benefit by optimizing the reactant ratios and using appropriate base catalysts, achieving high reaction efficiency without organic solvents and thus eliminating environmental pollution from solvent disposal

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The reaction is conducted in an inert environment by using water as a green solvent or performing the reaction under solvent-free conditions with nitrogen atmosphere, preventing unwanted side reactions while maintaining environmental compatibility and reaction reliability

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Manufacturing precision

If multiple reaction steps are used, then the desired pyrimidinylpyrazole compound can be obtained, but the production time and complexity increase

Engineering Contradiction:

Improveproduct purityVSAvoidsynthesis time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

Multiple reaction steps (condensation, cyclization, and dehydration) are merged into a single one-pot reaction sequence where all transformations occur sequentially in the same reaction vessel without isolation of intermediates, significantly reducing synthesis time while maintaining product purity through optimized reaction conditions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The reaction conditions are preliminarily optimized by selecting appropriate base catalysts and reactant ratios before the main reaction, ensuring that all subsequent transformations proceed smoothly in the correct sequence to achieve high purity products without requiring additional purification steps

Inventive Principle:

Principle #10Preliminary action

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 allows for the production of pyrimidinylpyrazole compounds from readily available, low-molecular-weight materials in one step, reducing environmental impact and operational costs while maintaining high efficiency.

Implementation Method 1

aminoguanidine represented by general formula (2) or its salt and a β-diketone compound represented by general formula (3) are reacted to produce the pyrimidinylpyrazole compound

Methodology Applied

Scientific EffectCondensation reaction:

Implementation Method 2

the method wherein a pyrimidinylpyrazole compound is produced by the cyclization reaction of a hydrazinylpyrimidine compound with a β-diketone compound

Methodology Applied

Scientific EffectCyclization reaction:

Data Source

PatentEP2527341B1Process for preparation of pyrimidinylpyrazole compounds

Publication Date: 2014.06.18 SHISEIDO CO LTD

AI summary

The present invention provides a method for producing a pyrimidinylpyrazole compound (1), wherein aminoguanidine (2) or its salt is reacted with a β-diketone compound (3) to produce the pyrimidinylpyrazole compound: wherein R1 and R3 are each independently an alkyl group having 1 to 4 carbon atoms, and R2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The method is excellent in the environmental compatibility and economic efficiency.