Diethyl Oxalate → HCID 178473094, compound

In 100 ml of EtOH was dissolved 2.99 g (126 mmol) of sodium under heating. The EtOH was evaporated under reduced pressure and the residue was suspended in THF (200 ml). The THF was evaporated. To the suspension of the residue in THF (124 ml) was added 18.1 g (124 mmol) of diethyl oxalate. Subsequently, to the above suspension was added at room temperature, 12 g (62 mmol) of 3-acetyl-5-chloroindole. After stirring for 3 hours, the mixture was stirred at 50° C. for additional 16 hours. The solvent was removed under reduced pressure. The resulting residue was washed with ether, and added to 1N hydrochloric acid (120 ml). The precipitated crystal was collected by filtration, and washed with water and ethyl acetate. Then the crystal was purified by recrystallization from dioxane and dried at 80° C. under reduced pressure to give 14.7 g of the titled compound. Yield: 81%.

1. temperatureunder heating
2. customThe EtOH was evaporated under reduced pressure
3. customThe THF was evaporated
4. additionTo the suspension of the residue in THF (124 ml)
5. additionSubsequently, to the above suspension was added at room temperature
6. stirringthe mixture was stirred at 50° C. for additional 16 hours
7. customThe solvent was removed under reduced pressure
8. washThe resulting residue was washed with ether
9. additionadded to 1N hydrochloric acid (120 ml)
10. filtrationThe precipitated crystal was collected by filtration
11. washwashed with water and ethyl acetate
12. customThen the crystal was purified by recrystallization from dioxane
13. customdried at 80° C. under reduced pressure

ORD record

ord-45c10d4aa20f45ee8dc858bc0070ca66

Source dataset

uspto-grants-2004_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06716605B2