97% 2,2-Dimethyl-5-(2-oxo-2-phenylethyl)-1,3-dioxane-4,6-dione CAS 74965-87-0

CAS Number:​​ 74965-87-0

​Molecular Formula:​​ C₁₄H₁₄O₅

​Molecular Weight:​​ 262.26 g/mol

​Structural Formula:​​ The molecule consists of a 1,3-dioxane ring where positions 4 and 6 are carbonyl carbons (a cyclic diacylal of malonic acid), creating a highly reactive "active methylene" center at C5. The phenacyl side chain is attached to this reactive center.

​IUPAC Name:​​ 2,2-Dimethyl-5-(2-oxo-2-phenylethyl)-1,3-dioxane-4,6-dione

​Synonyms:​​

5-Phenacyl-2,2-dimethyl-1,3-dioxane-4,6-dione

Phenacyl Meldrum's acid derivative

2,2-Dimethyl-5-phenacyl-1,3-dioxane-4,6-dione

​Physical State:​​ Typically a white to off-white crystalline solid.

​Melting Point:​​ Data specific to this compound is limited in public literature, but analogous Meldrum's acid derivatives often melt in the range of 100-150°C, depending on purity.

​Solubility:​​ Soluble in common organic solvents such as dichloromethane, chloroform, ethyl acetate, acetone, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). Sparingly soluble or insoluble in water and non-polar alkanes.

​Stability:​​ The 1,3-dioxane-4,6-dione ring is hydrolytically sensitive, especially under basic and acidic conditions, which can lead to ring-opening. It is also thermally labile and may undergo decarboxylation upon heating. Should be stored under anhydrous conditions, preferably in a cool, dry, and inert atmosphere.

​Reactivity:​​ The hallmark of Meldrum's acid derivatives is the high acidity of the proton at the 5-position (between two carbonyls) and the ring strain, making it a potent ​carbon nucleophile​ for alkylations and Michael additions. The ring can also act as a "malonyl equivalent" that readily undergoes ring-opening with nucleophiles or decarboxylative transformations.

​Direct Activity:​​ Primarily valued as a synthetic intermediate; there is no widely reported direct pharmacological or significant biological activity for this specific compound.

​Biological Relevance of Derivatives:​​ As a key building block, it is used to synthesize compounds with potential or established biological activities. These include:

        ​Heterocyclic Compounds:​​ Serves as a precursor for pyridines, pyrimidines, coumarins, and other fused ring systems found in many drugs.

        Functionalized Intermediates:​​ The reactive phenacyl and active methylene groups allow access to complex structures that could be developed into enzyme inhibitors or receptor ligands.

​Toxicity:​​ Specific toxicological data is limited. As with many reactive organic intermediates, standard laboratory precautions should be observed to avoid inhalation, ingestion, or skin/eye contact.

​Natural Occurrence:​​ This is a fully synthetic compound and is not known to be produced by any biological system.

​Laboratory/Industrial Synthesis:​​ It is synthesized chemically via the ​acylation of Meldrum's acid.

The starting material, 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum's acid), is deprotonated with a mild base (e.g., triethylamine, pyridine).

The resulting enolate undergoes nucleophilic attack on ​phenacyl bromide​ (2-bromoacetophenone) in an SN2-type alkylation reaction.

The product is isolated via standard workup and purification (e.g., filtration, recrystallization).

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​Q1: What is the main purpose of this compound?​​

A1: It is primarily used as a highly reactive, bifunctional building block in advanced organic synthesis, especially for constructing complex cyclic and heterocyclic frameworks relevant to pharmaceutical and materials research.

​Q2: How should it be stored to ensure stability?​​

A2: Store in a tightly sealed container under an inert atmosphere (argon or nitrogen) in a freezer (e.g., -20°C) to minimize hydrolysis and thermal degradation. Desiccants are recommended to exclude moisture.

​Q3: What are the main hazards associated with handling?​​

A3: While a full hazard assessment requires consulting the specific SDS, compounds of this class can be irritants to skin, eyes, and the respiratory system. The fine powder may form combustible dust clouds. Standard PPE (gloves, safety glasses, lab coat) and handling in a fume hood are essential.

​Q4: Can it be used in aqueous or mild reaction conditions?​​

A4: It is generally ​not compatible with protic or aqueous conditions​ due to the hydrolytic sensitivity of the dioxanedione ring. Reactions are typically performed in anhydrous organic solvents under inert atmospheres.

​Q5: What is a key reaction characteristic I should know about?​​

A5: A defining feature is its ​thermal lability. Upon heating, it readily undergoes a retro-Diels-Alder-type fragmentation, losing acetone and carbon dioxide. This can be a disadvantage for high-temperature reactions but is strategically used in decarboxylative coupling methodologies.

​Q6: Is it available from major chemical suppliers?​​

A6: It is considered a specialty or fine chemical. It may not be listed in mainstream catalogs but is often available from suppliers focusing on advanced synthetic intermediates or can be custom synthesized on a gram-to-kilogram scale.

​Q7: What analytical methods are used for quality control?​​

A7: Common methods include  

¹H- and  ¹³C-NMR spectroscopy for structural confirmation, HPLC for purity assessment, and melting point determination. IR spectroscopy can confirm the characteristic carbonyl stretches.

​Q8: What are common impurities in synthesized batches?​​

A8: Potential impurities include unreacted starting materials (Meldrum's acid, phenacyl bromide), hydrolysis products (malonic acid derivatives), or dialkylated by-products. Purification is typically achieved via recrystallization.