Trimethyl Orthoformate

Trimethyl Orthoformate
Other Names: TMOF, Methyl orthoformate, Orthoformic acid trimethyl ester

CAS Number: 149-73-5
Sum Formula: C₄H₁₀O₃
Molar Mass: 106.12 g/mol
Appearance: Colorless, clear liquid

Trimethyl orthoformate is an organic compound commonly used as a reagent and intermediate in chemical synthesis, particularly for introducing methoxy groups or protecting functional groups such as aldehydes and ketones. It is a volatile, flammable liquid with a mild odor.

Chemical and Physical Properties
Density: 0.97 g/cm³ (at 20°C)
Melting Point: -23°C
Boiling Point: 103–104°C
Solubility in Water: Reacts slowly (hydrolyzes)
Solubility in Other Solvents: Miscible with alcohols, ethers, and most organic solvents
Odor: Mild, ether-like
Vapor Pressure: ~50 mmHg (at 25°C)
Flash Point: 6°C (closed cup)

Applications

• Organic Synthesis: Used as a methylating agent and to form acetals/ketals in protective group chemistry.

• Industrial Chemistry: Intermediate in the manufacture of fine chemicals and specialty compounds.

• Solvent Systems: Occasionally used in formulation of solvent blends for reactions under anhydrous conditions.

Safety

Signal Word: Danger

First Aid Measures
Eye Contact: Rinse thoroughly with water for several minutes. Seek medical attention if irritation persists.
Skin Contact: Wash with soap and water. Remove contaminated clothing.
Inhalation: Move to fresh air. Seek medical help if symptoms such as dizziness or respiratory irritation occur.
Ingestion: Rinse mouth. Do not induce vomiting. Get medical attention if unwell.

Handling and Storage
Storage Conditions: Store in a tightly closed container in a cool, dry, well-ventilated area. Keep away from sources of ignition and incompatible substances (e.g. acids, moisture).
Handling Precautions: Use only with adequate ventilation. Avoid contact with skin, eyes, and clothing. Ground containers when transferring material.