p-Toluenesulfonic acid → HCID 69002385, compound

Participants

Reaction Steps

A mixture of hydroxy-(3-oxo-3,4-dihydro-2H-benzo[1,4]thiazin-2-yl)-acetic acid (0.13 mmol) and p-TSA (1 mg) in 1.5 mL of 2,2-dimethoxypropane is stirred at room temperature for 16 hours. Solvent is removed under vacuum and the residue is treated with a saturated aqueous solution of NaHCO3 (2 mL). The resulted mixture is extracted with EtOAc (3×5 mL). The organic layers are combined and concentrated to provide the crude 2-(2,2-dimethyl-5-oxo-[1,3]dioxolan-4-yl)-4H-benzo[1,4]thiazin-3-one which was used directly for next step without further purification. Yield: 31%

Provenance & Evidence