Trifluoroacetic acid → Ethyl 1-benzyl-4-(1-tert-butoxycarbonylaminocyclopropyl)-3-pyrroline-3-carboxylate

N-Benzyl-N-(n-butoxymethyl)trimethylsilylmethylamine (2.006 g, 7.176 mmol) and ethyl 3-(1-tert-butoxycarbonylaminocyclopropyl)propiolate (1.136 g, 4.485 mmol) were dissolved in dry dichloromethane (9 ml). While stirring at room temperature, a 1.0 M solution of trifluoroacetic acid in dichloromethane (0.72 ml, 0.72 mmol) was added thereto and the liquid reaction mixture was stirred for 3 hours. Then a saturated aqueous solution of sodium bicarbonate (20 ml) was added to the liquid reaction mixture followed by extraction with dichloromethane (20 ml×3). The combined organic layer was washed with a saturated aqueous solution of sodium chloride (30 ml) and dried over anhydrous magnesium sulfate. After filtering, the filtrate was concentrated under reduced pressure and the residue was subjected to flash silica gel column chromatography (eluent: chloroform) to obtain 1.449 g (83.6%) of the title compound as a colorless oily substance.

1. customthe liquid reaction mixture
2. stirringwas stirred for 3 hours
3. extractionfollowed by extraction with dichloromethane (20 ml×3)
4. washThe combined organic layer was washed with a saturated aqueous solution of sodium chloride (30 ml)
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationAfter filtering
7. concentrationthe filtrate was concentrated under reduced pressure

ORD record

ord-12f0bcb643624439a1fde0d8872257e5

Source dataset

uspto-grants-2000_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06121285