Trifluoroacetic anhydride → N-Cyclopropyl-3-propyloxirane-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a three-neck 250 mL round bottom flask equipped with mechanical stirrer and containing compound 37 (10.0 g, 65.3 mmol) and urea hydrogen peroxide (UHP) (25.0 g, 4.0 eq.) in CH2Cl2 (100 mL, 10 vol) at 0° C., was added trifluoroacetic anhydride (41.1 g, 27.2 mL, 3.0 eq.). The reaction mixture was heated to 35±5° C. and stirred for 2 hours. After cooling the reaction mixture down to room temperature, another aliquot of trifluoroacetic anhydride (13.7 g, 9.0 mL, 1.0 eq.) was added. The reaction mixture was heated again to 35±5° C. and stirred for another 3 hours. The reaction mixture was then again cooled to 0° C. and quenched by adding saturated NaHCO3 (5 vol.) slowly and stirring for 30 minutes. The organic layer was separated, and the aqueous layer was extracted with CH2Cl2 (50 mL, 5 vol). The combined organic layer was dried and evaporated to afford the crude product, N-cyclopropyl-3-propyloxirane-2-carboxamide (38), as a pale yellow oil. The crude product was used for the next step without further purification.

Provenance & Evidence