Pyridine → Ethyl 3-(butanoylamino)-2-oxobutanoate

온도

50 °C

The compound of formula VI (9.54 g, 0.06 mol) was dissolved into dried tetrahydrofuran (60 mL), and DMAP (0.24 g, 2.0 mmol) and pyridine (15 mL) were added therein. The mixture was heated for 30 minutes at 50° C., cooled, and slowly dropped with ethyl oxalyl monochloride (16.4 g, 0.12 mol) under an ice bath. After the dropping, the mixture was heated for 4 hours at 70° C., filtered to remove the solid, and evaporated to remove the solvent under reduced pressure. Water (100 mL) was added therein, and the product was extracted with ethyl acetate (120 mL×3). The liquid was separated, and the combined organic phase was washed by water (90 mL) and saturated saline (50 mL×2) respectively, dried over anhydrous sodium sulfate, and rotarily evaporated to remove the solvent. NaHCO3 (3.8 g, 0.045 mol) and methanol (50 mL) were added therein, and the reaction mixture was refluxed for 2 hours, filtered, and evaporated off the solvent under reduced pressure to obtain a yellow oil, i.e., ethyl 3-butyramido-2-oxo-butyrate, which was directly used in the next step without separation.

1. additionwere added
2. temperaturecooled
3. temperatureAfter the dropping, the mixture was heated for 4 hours at 70° C.
4. filtrationfiltered
5. customto remove the solid
6. customevaporated
7. customto remove the solvent under reduced pressure
8. additionWater (100 mL) was added
9. extractionthe product was extracted with ethyl acetate (120 mL×3)
10. customThe liquid was separated
11. washthe combined organic phase was washed by water (90 mL) and saturated saline (50 mL×2) respectively
12. dry with materialdried over anhydrous sodium sulfate
13. customrotarily evaporated
14. customto remove the solvent
15. temperaturethe reaction mixture was refluxed for 2 hours
16. filtrationfiltered
17. customevaporated off the solvent under reduced pressure

ORD 기록

ord-4b1cd59386c440998b78c9c7fae91b99

출처 데이터셋

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US08410098B2