Pyridine → (4-methylphenyl)sulfonyl acetate

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.

1. stirringthe mixture was stirred overnight
2. temperatureThe reaction was cooled to 5° C.
3. customquenched with 2 N aq NaOH to pH 7
4. customThe aqueous layer was separated
5. extractionextracted with dichloromethane (2×50 mL)
6. dry with materialThe combined organics were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. dissolutionThe resulting semi-solid was dissolved in isopropyl acetate (100 mL)
10. concentrationconcentrated to dryness
11. customThe resulting semi-solid was triturated in methyl tert-butyl ether (250 mL)
12. filtrationfiltered
13. customdried under vacuum

ORD record

ord-366fbad9cd6c4f22a2923d8a3a342e78

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658792B2