Methyl benzoylformate is the methyl ester of phenylglyoxylic acid, carrying an α-keto-aromatic structure. The conjugated benzoyl–ester moiety gives strong UV-A absorption (λmax ≈ 340 nm, log ε ≈ 3.9) and a high triplet-energy photoinitiating centre. The product is miscible with most acrylic monomers, ethanol, acetone and toluene, and is practically insoluble in water (< 0.5 g L⁻¹ at 25 °C). Commercial MBF is supplied at ≥ 99 % purity and remains stable for ≥ 2 years when stored at < 25 °C in tightly closed containers away from light .
Key Physicochemical Data:
Melting point: ≈ 16 °C
Boiling point: 247–248 °C / 760 mmHg
Density: 1.155–1.20 g cm⁻³ (20 °C)
Flash point: 103.8–115 °C (closed cup)
Log P (octanol/water): 1.4 (predicted)
Vapour pressure: < 0.1 mmHg at 25 °C
Typical Uses:
Type II photoinitiator for UV-LED or mercury-lamp curing of clear and pigmented coatings, inks, adhesives and 3-D printing resins at 0.5–3 % w/w; features low yellowing and low odour .
Key intermediate for the synthesis of the herbicide metamitron and other agrochemicals .
Building block for (R)-mandelic acid and subsequent semi-synthetic β-lactam antibiotics, antitumour and anti-obesity agents .
Quality Specification (Commercial Grade):
Purity (GC): ≥ 99 %
Water content (KF): ≤ 0.3 %
Free acid (as benzoic acid): ≤ 0.2 %
Residue on ignition: ≤ 0.1 %
Heavy metals: ≤ 20 ppm
Hazard Statement:
Causes skin and eye irritation (H315 + H319). Avoid inhalation of vapour; use gloves, goggles and adequate ventilation. Store in a cool, dry place away from oxidants and strong bases. SDS available on request.
