4-(Methylthio)phenylacetic acid is an aromatic sulfur-containing carboxylic acid featuring a methylthio group at the para-position of the phenyl ring. The compound is odorless to faintly sulfurous, air-stable, and readily soluble in common organic solvents (ethanol, methanol, ethyl acetate, dichloromethane) while only sparingly soluble in cold water.
Key physical data:
Melting point: 97–98 °C
Predicted b.p.: 337 °C (760 mmHg)
Density: 1.23 g cm⁻³
Predicted log P: 1.99
Flash point: 158 °C
Typical uses:
Key intermediate for the selective COX-2 inhibitor etoricoxib; the methylthio group is oxidized to the corresponding methylsulfone before further hetero-cyclisation .
Starting material for agro-chemicals, UV-absorbers and liquid-crystalline materials that require a lipophilic phenyl-acetic acid handle.
Internal standard for GC-MS quantitative analysis of methylthio-phenyl acetic acids in environmental samples.
Quality specification (commercial grade):
Purity (HPLC): ≥98 %
Water content (KF): ≤0.3 %
Residue on ignition: ≤0.1 %
Heavy metals: ≤20 ppm
Hazard statement:
Causes skin and eye irritation (R36/37/38). Avoid inhalation of dust; use gloves, goggles and adequate ventilation. SDS available on request .
