Lawesson's reagent → HCID 22335279, compound

Lawesson's reagent (10.1 g, 20 mmol) was added to a solution of benzyl 3-oxo-1-piperazinecarboxylate (10 g, 43 mmol) in tetrahydrofuran (110 mL), and the reaction heated under reflux for 4 hours. The cooled mixture was concentrated under reduced pressure and the residue partitioned between 1N sodium hydroxide solution (150 mL) and ethyl acetate (250 mL), and the layers separated. The organic extract was washed with 1N sodium hydroxide solution (2×100 mL), then brine (100 mL), and the combined aqueous solutions extracted with ethyl acetate (200 mL). The combined organic solutions were dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel using dichloromethane:methanol (98:2) as eluant to afford the title compound as a tan-coloured solid, 6.7 g.

1. temperaturethe reaction heated
2. temperatureunder reflux for 4 hours
3. concentrationThe cooled mixture was concentrated under reduced pressure
4. customthe residue partitioned between 1N sodium hydroxide solution (150 mL) and ethyl acetate (250 mL)
5. customthe layers separated
6. extractionThe organic extract
7. washwas washed with 1N sodium hydroxide solution (2×100 mL)
8. extractionbrine (100 mL), and the combined aqueous solutions extracted with ethyl acetate (200 mL)
9. dry with materialThe combined organic solutions were dried (MgSO4)
10. concentrationconcentrated under reduced pressure
11. customThe crude product was purified by column chromatography on silica gel

ORD record

ord-d8b364a26ce94324809d7dd0dfe1d9f2

Source dataset

uspto-grants-2005_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06936619B2