ortho-Methyl, para-thiol phenol combining –OH and –SH on the same ring. The methyl group increases electron density (pKₐ phenol ≈ 10.2; pKₐ thiol ≈ 6.8), enabling:
Antioxidant & metal chelator – stronger radical-scavenging activity than BHT at 100 ppm; forms stable Cu²⁺/Fe³⁺ complexes for lube-oil additives;
Pharmaceutical intermediate – building block for benzoxazine and benzothiazine APIs, prepared by one-pot cyclisation with aldehydes;
Polymer modifier – chain-transfer agent in RAFT polymerisation, giving high-refractive-index poly(aryl sulfide) resins (nD ≈ 1.68) for OLED films;
SERS sensor – self-assembled monolayer on gold, with the methyl group reducing surface defect density by 20 %, enhancing Hg²⁺ detection sensitivity;
Antimicrobial agent – recent patent shows MIC 8 µg mL⁻¹ against MRSA and E. coli through membrane disruption .
Store under nitrogen at 2–8 °C, away from oxidants.
