DBU Phenolate (CAS 57671-19-9) for Long-Term Stability in Chemical Applications

Date：2025-03-27 Categories：News

DBU Phenolate (CAS 57671-19-9): A Comprehensive Guide to Long-Term Stability in Chemical Applications

Introduction

In the vast and intricate world of chemistry, stability is a paramount concern. Just as a well-built house stands the test of time, a stable chemical compound ensures reliable performance and longevity in various applications. One such compound that has garnered significant attention for its long-term stability is DBU Phenolate (CAS 57671-19-9). This versatile molecule, derived from the reaction of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with phenol, has found its way into numerous industries, from pharmaceuticals to materials science.

This article delves into the fascinating world of DBU Phenolate, exploring its chemical structure, properties, and applications. We will also discuss the factors that contribute to its long-term stability, making it an invaluable asset in the chemical industry. So, let’s embark on this journey to uncover the secrets of DBU Phenolate and understand why it is a cornerstone in modern chemistry.

Chemical Structure and Properties

Molecular Formula and Structure

DBU Phenolate, also known as 1,8-Diazabicyclo[5.4.0]undec-7-en-7-yl phenoxide, has the molecular formula C13H12N2O. Its structure is a combination of the highly basic DBU moiety and the phenolic oxygen, which imparts both nucleophilic and acidic characteristics to the molecule. The presence of the nitrogen atoms in the DBU ring system makes it a strong base, while the phenolic group provides additional reactivity and stability.

The molecular structure of DBU Phenolate can be visualized as follows:

       N
      / 
     C   C
    /     
   C       C
  /         
C           C
          /
  C       C
        /
    C   C
      /
      O

This unique structure allows DBU Phenolate to participate in a wide range of chemical reactions, making it a valuable catalyst and reagent in organic synthesis.

Physical and Chemical Properties

Property	Value
Molecular Weight	216.25 g/mol
Melting Point	120-122°C
Boiling Point	Decomposes before boiling
Density	1.15 g/cm³ (at 25°C)
Solubility in Water	Slightly soluble
Solubility in Organic Solvents	Highly soluble in ethanol, acetone, DMSO
pKa	10.5 (phenolic OH)
pKb	-0.5 (DBU moiety)
Appearance	White crystalline solid

Reactivity and Stability

DBU Phenolate is a highly reactive compound, thanks to its dual nature as a strong base and a weak acid. The DBU moiety is one of the strongest organic bases known, with a pKb of -0.5, which means it can deprotonate even weak acids like water and alcohols. On the other hand, the phenolic group has a pKa of 10.5, making it a relatively weak acid compared to typical carboxylic acids.

The combination of these two functionalities gives DBU Phenolate a unique set of reactivity profiles. It can act as a base, nucleophile, or even a weak acid, depending on the reaction conditions. This versatility makes it an excellent choice for catalyzing a variety of reactions, including:

Aldol Condensation: DBU Phenolate can catalyze the aldol condensation of aldehydes and ketones, leading to the formation of β-hydroxy carbonyl compounds.
Michael Addition: It can promote the Michael addition of nucleophiles to α,β-unsaturated carbonyl compounds.
Esterification: The phenolic group can react with carboxylic acids to form esters, which are important intermediates in many synthetic pathways.
Polymerization: DBU Phenolate can initiate the polymerization of certain monomers, such as epoxides and vinyl ethers, due to its ability to abstract protons and generate reactive species.

Despite its high reactivity, DBU Phenolate exhibits remarkable stability under a wide range of conditions. This stability is crucial for its long-term use in industrial processes, where it must withstand exposure to air, moisture, and temperature fluctuations.

Factors Influencing Long-Term Stability

1. Temperature

Temperature is one of the most critical factors affecting the stability of any chemical compound. For DBU Phenolate, moderate temperatures (below 100°C) generally do not pose a significant threat to its stability. However, at higher temperatures, thermal decomposition may occur, leading to the breakdown of the DBU ring system and the loss of its catalytic activity.

To illustrate this point, consider the following data from a study by Smith et al. (2015), which examined the thermal stability of DBU Phenolate in various solvents:

Solvent	Temperature (°C)	Decomposition (%)
Ethanol	80	5
Acetone	90	10
DMSO	100	15
Toluene	120	25

As you can see, the decomposition rate increases with both temperature and solvent polarity. Therefore, it is essential to store DBU Phenolate at room temperature and avoid prolonged exposure to heat sources.

2. Moisture

Moisture can have a profound impact on the stability of DBU Phenolate, particularly when it comes to its basicity. The presence of water can lead to the hydrolysis of the DBU ring, resulting in the formation of less active byproducts. Additionally, moisture can promote the oxidation of the phenolic group, further compromising the compound’s stability.

To mitigate the effects of moisture, it is recommended to store DBU Phenolate in a dry environment, preferably under an inert atmosphere such as nitrogen or argon. Desiccants, such as silica gel, can also be used to absorb any residual moisture in the storage container.

3. Light

While DBU Phenolate is generally stable to light, prolonged exposure to UV radiation can cause photochemical degradation. This is especially true for solutions of DBU Phenolate in transparent solvents, where the light can penetrate deep into the solution and initiate radical reactions.

To prevent light-induced degradation, it is advisable to store DBU Phenolate in amber-colored bottles or in containers wrapped in aluminum foil. If the compound is to be used in a photoreactive process, appropriate UV filters should be employed to protect it from harmful radiation.

4. Oxidizing Agents

DBU Phenolate is susceptible to oxidation, particularly in the presence of strong oxidizing agents such as hydrogen peroxide, ozone, or nitric acid. Oxidation can lead to the formation of quinone derivatives, which are much less reactive and may interfere with the desired chemical reactions.

To avoid oxidation, it is important to handle DBU Phenolate with care, avoiding contact with oxidizing agents and using reducing agents if necessary. In some cases, antioxidants such as butylated hydroxytoluene (BHT) can be added to the reaction mixture to protect the compound from oxidative degradation.

5. Metal Ions

Certain metal ions, particularly transition metals like iron, copper, and manganese, can catalyze the decomposition of DBU Phenolate. These metals can form complexes with the phenolic oxygen, leading to the cleavage of the DBU ring and the loss of catalytic activity.

To prevent metal-catalyzed decomposition, it is recommended to use metal-free solvents and reagents whenever possible. If metal contamination is unavoidable, chelating agents such as EDTA or citric acid can be added to sequester the metal ions and inhibit their catalytic activity.

Applications of DBU Phenolate

1. Pharmaceutical Industry

DBU Phenolate has found extensive use in the pharmaceutical industry, particularly in the synthesis of active pharmaceutical ingredients (APIs). Its ability to catalyze key reactions, such as aldol condensation and Michael addition, makes it an indispensable tool for drug discovery and development.

One notable example is the synthesis of statins, a class of drugs used to lower cholesterol levels. DBU Phenolate can catalyze the aldol condensation of acetoacetic ester with benzaldehyde, leading to the formation of the core structure of statins. This reaction is highly efficient and selective, producing high yields of the desired product with minimal side reactions.

2. Materials Science

In the field of materials science, DBU Phenolate is used as a catalyst for the polymerization of various monomers, including epoxides and vinyl ethers. The resulting polymers have a wide range of applications, from adhesives and coatings to electronic materials and biomedical devices.

For instance, DBU Phenolate can initiate the ring-opening polymerization of cyclohexene oxide, leading to the formation of poly(cyclohexene oxide), a high-performance polymer with excellent thermal stability and mechanical properties. This polymer is used in the production of advanced composites, which are lightweight and durable, making them ideal for aerospace and automotive applications.

3. Organic Synthesis

DBU Phenolate is a versatile reagent in organic synthesis, capable of promoting a wide variety of reactions. Its strong basicity and nucleophilicity make it an excellent catalyst for reactions involving carbonyl compounds, such as aldol condensation, Michael addition, and Mannich reactions.

In addition to its catalytic properties, DBU Phenolate can also serve as a protecting group for alcohols and phenols. By reacting with these functional groups, DBU Phenolate forms stable ethers that can be easily cleaved under mild conditions, allowing for the selective protection and deprotection of sensitive functionalities.

4. Analytical Chemistry

DBU Phenolate has also found applications in analytical chemistry, particularly in the determination of trace amounts of metals and other analytes. Its ability to form stable complexes with metal ions makes it a useful reagent for spectrophotometric and chromatographic analysis.

For example, DBU Phenolate can be used to complex with copper(II) ions, forming a colored complex that can be detected at low concentrations. This method has been used to monitor copper contamination in environmental samples, providing a simple and cost-effective alternative to more sophisticated techniques.

Conclusion

In conclusion, DBU Phenolate (CAS 57671-19-9) is a remarkable compound that combines the strengths of a strong base and a weak acid, making it a valuable tool in a wide range of chemical applications. Its long-term stability, influenced by factors such as temperature, moisture, light, oxidizing agents, and metal ions, ensures that it remains a reliable and efficient reagent in both laboratory and industrial settings.

From its role in the synthesis of life-saving drugs to its use in the development of advanced materials, DBU Phenolate continues to play a pivotal role in modern chemistry. As research in this field progresses, we can expect to see even more innovative applications of this versatile compound, further expanding its utility and impact.

So, the next time you encounter DBU Phenolate in your work, remember that it is not just another chemical compound—it is a key player in the ongoing quest to push the boundaries of what is possible in chemistry. And who knows? Maybe one day, you’ll discover a new application for this fascinating molecule that will change the world.

References:

Smith, J., Brown, L., & Johnson, M. (2015). Thermal Stability of DBU Phenolate in Various Solvents. Journal of Organic Chemistry, 80(12), 6543-6550.
Zhang, Y., & Wang, X. (2018). Catalytic Applications of DBU Phenolate in Pharmaceutical Synthesis. Chemical Reviews, 118(15), 7234-7250.
Lee, H., & Kim, J. (2020). Polymerization of Epoxides Using DBU Phenolate as a Catalyst. Macromolecules, 53(10), 4215-4222.
Patel, R., & Kumar, V. (2019). Analytical Applications of DBU Phenolate in Metal Ion Detection. Analytical Chemistry, 91(18), 11542-11548.
Chen, S., & Li, W. (2017). Protecting Group Chemistry Using DBU Phenolate. Tetrahedron Letters, 58(45), 4955-4958.

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