[1] Controllable Phosphorylation of Thioesters: Selective Synthesis of Aryl and Benzyl Phosphoryl Compounds. J. Org. Chem. 2020, 85, 22, 14653–14663.
A mixture of a well-powdered benzoic anhydride (6.0 mmol), thiourea (6.5 mmol), and Et3N (2.5 mL) was stirred at 40 °C until the starting anhydride was completely consumed and a two-phase system containing Et3N and a thick brick-red liquid was formed. Then, water (5.0 mL) and CH3I (5.0 mmol) were added to the mixture, and stirring was continued at room temperature. After consumption of starting CH3I (3 h), the crude product was extracted with EtOAc (15 mL × 2). The crude product was purified by column chromatography over silica gel (300–400 mesh) using petroleum ether/ethyl acetate as an eluent to give analytically pure product (S)-methyl thiobenzoate.
