Pyridinium p-toluenesulfonate (PPTS) is a heterocyclic organic compound used as a mild and efficient catalyst for forming and cleaving acetals; under conditions where tert-butyl diphenylsilyl, TBDPS, and ethers are present, it selectively cleaves tert-butyl dimethylsilyl, TBDMS, and ethers. It serves as a mild and effective catalyst for synthesizing and separating acetals, specifically under the presence of tert-butyl diphenylsilyl, TBDPS, and ethers, where it selectively cleaves tert-butyl dimethylsilyl, TBDMS, and ethers.
Under nitrogen protection, add 4-methylbenzenesulfonic acid (5g, 0.029 mol) and anhydrous tetrahydrofuran (40 mL) to the reactor, and stir at room temperature. Cool the reaction mixture to 0-5°C. At this temperature, slowly add a tetrahydrofuran solution of pyridine (2.75g, 0.035 mol) over 20 to 30 minutes, then continue stirring for another 30 minutes. After completion of the reaction, filter the reaction mixture under a nitrogen atmosphere to collect the solid product. Wash the filter cake with anhydrous tetrahydrofuran (5 mL), then place the wet filter cake in a vacuum oven and dry it at 45-50°C for 4 hours to obtain pyridinium 4-methylbenzenesulfonate. The product yield is 6g, with a yield of 82.19%, and HPLC purity detection shows 100%.