1-Fluoro-4-(isocyanatomethyl)benzene → 1,1-Dicyclopropyl-N-[(4-fluorophenyl)methyl]-tetrahydro-3-oxo-3H-oxazolo[3,4-a]pyrazine-7(1H)-carboxamide

Participants

Reaction Steps

(Phenylmethyl)1,1-dicyclopropyl-tetrahydro-3-oxo-3H-oxazolo[3,4-a]pyrazine-7(1H)-carboxylate (0.18 g, 0.50 mmol) was dissolved in ethanol (10 mL). 10% Palladium carbon (17 mg) was added thereto, and the mixture was stirred under hydrogen atmosphere at room temperature overnight. The reaction solution was filtered through Celite, the Celite was washed with ethanol, and the filtrate was concentrated under reduced pressure. The resulting 1,1-dicyclopropyl-hexahydro-3H-oxazolo[3,4-a]pyrazin-3-one was dissolved in tetrahydrofuran (10 mL). (4-Fluoro)benzyl isocyanate (0.25 mL, 2.0 mmol) was added thereto, and the mixture was stirred at 50° C. for 4 hours. The reaction solution was concentrated under reduced pressure, and the residue was purified with silica gel column chromatography (hexane:ethyl acetate=1:1 to 1:4) to obtain the title compound (0.16 g, 87% yield from (phenylmethyl) 1,1-dicyclopropyl-tetrahydro-3-oxo-3H-oxazolo[3,4-a]pyrazine-7(1H)-carboxylate).

Provenance & Evidence