Ethyl Cyanoacetate (CAS No. 105-56-6) is an organic synthetic intermediate featuring high reactivity and strong selectivity. As a foundational raw material in the fine chemical and polymer materials industries, ethyl cyanoacetate plays a vital role across pharmaceutical intermediates, agrochemicals, specialty adhesives (such as $\alpha$-cyanoacrylate instant glues), dyes and pigments, and polymer modification due to the synergistic response of the cyano and ester groups within its molecular structure.

To help industrial users and trade partners better understand its physicochemical properties, production methods, quality standards, and operational safety, here is a structured FAQ guide:

Frequently Asked Questions (FAQ)

Q1: What are the fundamental physicochemical parameters of ethyl cyanoacetate? What are the key features of its molecular structure?

A:

• Basic Information: CAS No. 105-56-6, Molecular Weight: 113.12, Relative Density: approximately 1.06 g/cm³ (at 20 °C), Boiling Point Range: 205–209 °C, Flash Point: approximately 98 °C.

• Physical Appearance: At ambient temperature, it presents as a clear, colorless to slightly yellowish liquid. It is slightly soluble in water and miscible with organic solvents such as ethanol, ether, and ethyl acetate.

• Structural & Reaction Features: The molecule contains both a strongly electron-withdrawing cyano group and an ester group. The methylene group flanked by these two functional groups exhibits active alpha-hydrogen characteristics, imparting high reactivity in Knoevenagel condensation, Michael addition, and cyclization reactions. Compared to its methyl counterpart, the ethyl group provides slightly higher steric hindrance, aiding better control over reaction rates and exothermicity in multi-step synthesis.

Q2: What is the primary industrial production process for ethyl cyanoacetate?

A: Industrial preparation of ethyl cyanoacetate relies primarily on the esterification and cyanation of chloroacetic acid (sodium cyanide route):

• Process Flow: Starting with chloroacetic acid (MCA) as the raw material, esterification with ethanol in the presence of an acid catalyst yields ethyl chloroacetate. Ethyl chloroacetate then undergoes nucleophilic substitution (cyanation) with sodium cyanide or potassium cyanide under mild conditions to generate crude ethyl cyanoacetate.

• Purification & Solidification: The crude liquid undergoes desalting, phase extraction, solvent recovery, and high-vacuum fractional distillation to yield high-purity industrial-grade or pharmaceutical-grade product with an assay content reaching 99.5% or higher.

• Process Features: This process route is mature with stable yields, making it suitable for continuous large-scale manufacturing. Fractional distillation is critical to strictly controlling moisture and residual alcohol impurities.

Q3: What are the primary industrial applications of ethyl cyanoacetate?

A: As an organic synthetic intermediate, ethyl cyanoacetate serves key functions across multiple high-tech sectors:

1. Specialty Adhesive Manufacturing: Serves as the core monomer raw material for producing ethyl $\alpha$-cyanoacrylate (industrial and medical instant glue/502 adhesive), imparting rapid curing speed and exceptional bond strength.

2. Pharmaceutical Intermediates: Used to construct pyrimidine, pyridine, triazole, and heterocyclic frameworks, widely applied in synthesizing antimicrobials (such as nifuratel), cardiovascular agents, and antineoplastic active molecules.

3. Agrochemicals: Used in synthesizing key intermediates for efficient, low-toxicity heterocyclic fungicides, herbicides, and plant growth regulators.

4. Polymer Modification & Coatings: Serves as a modifying monomer for acrylic resins and specialty polymer resins, enhancing coating adhesion to metallic substrates, weatherability, and UV degradation resistance.

Q4: What quality indicators and testing standards apply to ethyl cyanoacetate?

A: According to fine chemical industrial testing standards, quality control focuses on:

• Assay (Purity): Standard industrial specifications typically mandate a main assay content (determined via Gas Chromatography, GC) of ≥ 99.0%, with pharmaceutical/high-purity grades requiring ≥ 99.5%.

• Key Quality Parameters:

  • Moisture (Karl Fischer Method): Controlled at ≤ 0.10%, as elevated moisture can promote hydrolysis into corrosive cyanoacetic acid and affect the shelf stability of downstream adhesives.

  • Residual Alcohol (Ethanol) & Free Acidity: Residual ethanol is kept low, while acidity (calculated as cyanoacetic acid) is typically controlled at ≤ 0.10%.

  • Appearance & Color: Required to be a clear, colorless to slightly yellowish liquid, with a Platinum-Cobalt color rating (APHA) below 20.

• Assay Method: Gas Chromatography (GC) is used for quantitative analysis of the main assay and organic impurities, while moisture is measured via Karl Fischer titration.

Q5: What are the safety handling, storage, and transport requirements for ethyl cyanoacetate?

A: Ethyl cyanoacetate is classified as a low-toxicity, irritating organic chemical.

• Personal Protection: Personnel handling ethyl cyanoacetate must wear dust/gas masks, chemical safety goggles, chemical-resistant gloves, and protective clothing to avoid eye contact, skin contact, or vapor inhalation. In case of skin exposure, flush immediately with copious running water.

• Packaging & Storage: Store in a cool, dry, well-ventilated warehouse maintained at +5 °C to +25 °C. Keep away from heat sources and open flames, and protect from direct sunlight. High-density polyethylene (HDPE) drums, lined steel drums, or aluminum drums with nitrogen blanketing are recommended.

• Incompatible Substances & Transport: Do not store or transport together with strong bases, strong acids, strong oxidizers, or aliphatic amines, as these can catalyze self-polymerization or exothermic reactions. Ensure containers remain sealed and undamaged during transport, displaying clear chemical handling labels.