1. Chemical Structure and Properties

Molecular Formula:

C₂H₇N

Structural Formula:

(CH₃)₂NH – A secondary aliphatic amine consisting of two methyl groups bonded to a central nitrogen atom.

Physical Properties:

• State: Colorless gas at room temperature; commonly handled as a 40% aqueous solution (boiling point ~51°C).
• Density: 0.68 g/cm³ (liquid); Vapor Pressure: 430 kPa at 20°C.
• Odor: Strong, fishy ammonia-like odor detectable at 0.03 ppm.
• Solubility: Fully miscible with water, ethanol, and ether.

Chemical Properties:

• Basicity: Weak base (pKa = 10.73), reacts with acids to form salts (e.g., dimethylamine hydrochloride).
• Reactivity: Participates in alkylation, acylation, and condensation reactions; flammable (flash point: -37°C).

2. Industrial Applications

Agrochemicals:

• Herbicide Production: Intermediate for glyphosate and 2,4-D herbicides.
• Insecticides: Synthesis of imidacloprid (neonicotinoid class).

Pharmaceuticals:

• Drug Synthesis: Building block for diphenhydramine and fluoxetine.

Rubber Industry:

• Vulcanization Accelerator: Produces tetramethylthiuram disulfide (TMTD).

Water Treatment:

• Corrosion Inhibitor: Forms protective amine films for pipelines.

Surfactants & Polymers:

• Quaternary Ammonium Salts: Produces cationic surfactants for detergents and fabric softeners.

Organic Synthesis:

• Catalyst in Grignard and polymerization processes (e.g., polyurethane foams).

3. Safety and Toxicology

Health Hazards:

• Inhalation (≥50 ppm): Severe respiratory irritation, pulmonary edema (LC50 rat, 4h: 4,400 ppm).
• Skin Contact: Corrosive burns and frostbite (liquid; rabbit skin LD50: 400 mg/kg).
• Eye Exposure: Permanent corneal damage.
• Ingestion: Highly toxic (oral LD50 rat: 540 mg/kg); causes necrosis.

Acute & Chronic Effects:

• Chronic Exposure: Potential liver/kidney damage and neurotoxicity.

Fire & Explosion Risks:

• Extremely flammable gas (range: 2.8–14.4% vol in air).
• Reacts violently with oxidizers (e.g., chlorine, nitric acid).

Protection Measures:

• PPE: Neoprene gloves, goggles, NIOSH respirators.
• Controls: Explosion-proof ventilation, gas detection systems.

4. Environmental & Regulatory Compliance

Environmental Impact:

• Aquatic Toxicity: LC50 fish: 100–200 mg/L; EC50 daphnia: 50–100 mg/L.
• Biodegradability: Rapid aerobic (half-life<5 days).
• Atmospheric Fate: Reacts with hydroxyl radicals (half-life ~8 hours).

Regulatory Frameworks:

• GB 13690-2009: Class 2.1 Flammable Gas & Class 8.2 Corrosive.
• OSHA PEL: 10 ppm; EPA TRI RQ = 100 lbs.
• CLP: Flammable Gas 1, Skin Corr. 1B, Acute Tox. 3.
• REACH: SDS required with mitigation measures.

Transport:

UN 1032 (anhydrous), UN 1163 (solution); Hazard Class: 2.1.

5. Case Studies & Insights

Case 1: Glyphosate Synthesis

DMA reacts with phosphorus trichloride for bisphosphonomethylamine precursor (Monsanto process); 40% solution yields 88% at 60°C.

Case 2: Pipeline Corrosion Inhibition

Chevron uses DMA-based filming amines to protect pipelines, reducing corrosion by 85% at 20 ppm.

Comparative Analysis:

• Pros: High reactivity in alkylation, low odor threshold.
• Cons: TMA offers better thermal stability.