Trifluoroacetic acid → N-[(4'R)-2''-amino-2',2'-dimethyldispiro[cyclopropane-1,3'-chromene-4',4''-[1,3]oxazol]-6'-yl]-5-(difluoromethyl)pyrazine-2-carboxamide

Participants

Reaction Steps

To a solution of tert-butyl [(4′R)-6′-({[5-(difluoromethyl)pyrazin-2-yl]carbonyl}amino)-2′,2′-dimethyldispiro[cyclopropane-1,3′-chromene-4′,4″-[1,3]oxazol]-2″-yl]carbamate (373 mg, 0.704 mmol) in chloroform (6 ml) was added trifluoroacetic acid (2 ml). The mixture was stirred at room temperature for 2 hours and concentrated in vacuo. The residue was purified by silica gel column chromatography (precolumn: NH-silica gel, main column: neutral silica gel, chloroform/methanol=100:0-10:1). To the purified product was added a mixture of hexane and ethyl acetate (4:1), and the mixture was stirred at room temperature over night. The resulting precipitate was collected, washed with a mixture of hexane and ethyl acetate (4:1), and dried in vacuo to afford N-[(4′R)-2″-amino-2′,2′-dimethyldispiro[cyclopropane-1,3′-chromene-4′,4″-[1,3]oxazol]-6′-yl]-5-(difluoromethyl)pyrazine-2-carboxamide (253 mg).

Provenance & Evidence