Methyl acetoacetate

Product Details

CasNo： 105-45-3

MF： C5H8O3

Appearance： liquid

Delivery Time： 15 days

Packing： 200kg/drum

Purity： 99%

1. Basic Information

• Synonyms: Butanoic acid, 3 - oxo -, methyl ester; Acetoacetic acid, methyl ester; Methyl acetylacetate; Methyl 3 - oxo butyrate; Methyl 3 - oxobutanoate; 3 - Oxo butanoic acid methyl ester; 3 - Oxo butyric acid methyl ester; Acetoacetate methyl ester; Methyl 2 - acetoacetate
• Molecular Formula: C?H?O?
• Molecular Weight: 116.12 g/mol
• CAS Registry Number: 105 - 45 - 3
• EINECS Registry Number: 203 - 299 - 8

2. Physical and Chemical Properties

2.1 Physical Properties

• Appearance: It is a clear, colorless liquid with a characteristic and pleasant aromatic odor.
• Melting Point: - 80 °C (lit.)
• Boiling Point: 169 - 170 °C/70 mmHg (lit.), or approximately 172 °C at normal pressure. It shows a slight decomposition between 169 - 171 °C.
• Density: 1.076 g/mL at 25 °C (lit.), or 1.0762 g/cm³ at 20/4 °C. It is denser than water.
• Vapor Density: 4 (vs air), meaning its vapors are heavier than air.
• Vapor Pressure: 1 hPa (20 °C), or 0.8 kPa (25 °C).
• Refractive Index: n??/D 1.419 (lit.).
• Flash Point: 158 °F (70 °C, closed cup). It is combustible when exposed to heat or flame.
• Solubility: Solubility in water is 460 g/L at 20 °C, so it is slightly soluble in water. It is highly soluble in organic solvents such as ethanol, ethyl ether, and can be miscible with them.
• Color: APHA: ≤ 20.
• Odor Type: Fruity.
• pH: 3.8 (863 g/L, H?O, 20 °C).
• Explosive Limit: 1.3 - 14.2% (v).

2.2 Chemical Properties

• Methyl acetoacetate is an ester. It can react with acids, liberating heat along with the formation of alcohols and acids. When reacting with strong oxidizing acids, a vigorous reaction may occur, which can be exothermic enough to ignite the reaction products. It also generates heat when interacting with caustic solutions. In addition, when mixed with alkali metals and hydrides, flammable hydrogen can be generated.
• It gives a deep red color when reacting with ferric chloride. The hydroxyl radical reaction rate constant is 3.25 x 10?¹³ cu cm/molecule sec at 25 °C. When boiled with water, it will decompose into acetone, methanol, and carbon dioxide.

3. Production Methods

• Method 1: From Diketene and Methanol
  • Similar to the preparation of ethyl acetoacetate, diketene and methanol are used as raw materials. The reaction is catalyzed by sulfuric acid. First, diketene reacts with methanol to form a crude product, and then the crude product is refined through rectification to obtain the final product of methyl acetoacetate. The reaction equation can be simply expressed as: C4?H4?O2?+CH3?OHH2?SO4??C5?H8?O3?.
• Method 2: From Acetic Acid Derivatives
  • Acetic acid can be first pyrolyzed to obtain diketene. Then, diketene reacts with methanol in the presence of a catalyst (such as concentrated sulfuric acid) for esterification. After that, through processes like rough fractionation and rectification, pure methyl acetoacetate is obtained. The overall process involves multiple steps: acetic acid first undergoes a series of reactions to form diketene, and then diketene is converted to the target product with methanol.

4. Toxicity

• It has moderate toxicity. The oral LD?? (median lethal dose) in rats is 3.0 g/kg (Smyth, Carpenter). It is also a skin and severe eye irritant.

5. Quality Specifications

• Generally, high - quality methyl acetoacetate should have a purity of ≥99%. The content of related impurities is strictly controlled. For example, the content of methanol should be ≤0.3%, the content of methyl formate should be ≤0.2%, and the content of other impurities should be ≤0.05%.

6. Applications

6.1 In the Pharmaceutical Industry

• Synthesis of Pharmaceuticals: It is a crucial chemical reagent for pharmaceutical synthesis. For instance, it participates in the Biginelli reaction, which is important for forming molecules such as dihydropyrimidinones. It is used in the synthesis of pyrazoles, coumarins, barbiturates, and other pharmaceutical - related compounds. It can also be used in the synthesis of some antipsychotic drugs as an important intermediate.
• pH Modifier in Drug Development: Due to its acidic nature, it can be used to adjust the pH of drug formulations in some cases, which helps to enhance the stability and solubility of certain compounds in drug development.

6.2 In the Pesticide Industry

• Intermediate for Pesticide Synthesis: It is an intermediate for many pesticides. For example, it is used in the synthesis of fungicides such as hymexazol, dimethirimol, and ethirimol, insecticides such as diazinon, coumaphos, and pirimiphos - ethyl, herbicides such as imazethapyr, and rodenticides such as coumatetralyl and warfarin.

6.3 In the Food and Flavor Industry

• Flavoring Agent: It is used as a flavoring agent in various food products. It imparts a fruity or sweet aroma. It is added in small amounts to enhance the flavor profiles of candies, baked goods, beverages, and dairy products. In the flavor industry, it can also serve as a precursor for the synthesis of other flavor compounds, providing fruity and creamy notes in flavor formulations.

6.4 In the Personal Care Industry

• Fragrance Ingredient: In cosmetics and personal care products, it is used as a fragrance ingredient to give a mild, sweet, and fruity scent. It can be found in perfumes, colognes, and deodorants.
• Solvent: It can act as a solvent in some cosmetic formulations, helping to dissolve other ingredients and ensuring a uniform texture and consistency in creams and lotions.

6.5 In the Textile and Dye Industry

• Dye Intermediate: In the textile industry, it is used as an intermediate in the synthesis of certain dyes and pigments, especially those used for dyeing synthetic fibers.

6.6 In General Organic Synthesis

• Intermediate in Organic Synthesis: It is widely used as an intermediate in the synthesis of various organic compounds, including dyes, agrochemicals, and other esters. It can also be used as a solvent or co - solvent in specific chemical reactions and processes due to its ability to dissolve a range of organic compounds. In some chemical processes, it acts as a chelating agent, helping to bind metal ions and prevent unwanted reactions.

7. Packaging and Storage

• Packaging: Usually packaged in 200 - KG drums. For some special needs, it can also be sub - packaged into 25 - KG drums. The packaging materials should be corrosion - resistant and tightly sealed to prevent leakage and contact with air and moisture.
• Storage: It should be stored in a cool, well - ventilated warehouse, away from fire sources and heat. It should be stored according to the regulations for flammable and toxic chemicals. Avoid exposure to sunlight and high temperatures, and keep it away from oxidizing agents and alkaline substances to prevent chemical reactions.