Pyridine → (4-methylphenyl)sulfonyl acetate

Participants

Reaction Steps

To a solution of 7 (10 g, 40 mmol, 1 equiv) and pyridine (22.6 mL, 280 mmol, 7 equiv) in dichloromethane (200 mL) was added p-toluenesulfonyl chloride (11.4 g, 60 mmol, 1.5 equiv). The mixture stirred at room temperature overnight. Pyridine (22.6 mL, 280 mmol, 7 equiv) and acetic anhydride (21.9 mL, 232 mmol, 5.8 equiv) were added at room temperature and the mixture was stirred overnight. The reaction was cooled to 5° C. and quenched with 2 N aq NaOH to pH 7. The aqueous layer was separated and extracted with dichloromethane (2×50 mL). The combined organics were dried over sodium sulfate, filtered, and concentrated. The resulting semi-solid was dissolved in isopropyl acetate (100 mL) and concentrated to dryness. This was repeated 2 more times. The resulting semi-solid was triturated in methyl tert-butyl ether (250 mL), filtered and dried under vacuum to afford 8.1 g of 8 (45%) as a pale yellow solid.

Provenance & Evidence