Triethylamine → 7-(2,2-dimethyl-1,3-dioxolan-4-yl)-9b-morpholino-3-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-4,9b-dihydro-3aH-chromeno[3,4-d]isoxazole

Participants

Reaction Conditions

Reaction Steps

To a solution of the N-hydroxy-3-phenyl-4-(trifluoromethyl)isoxazole-5-carbimidoyl chloride (Intermediate 1-12, 0.340 g, 1.170 mmol) in dichloromethane (3.5 mL) was added 4-(7-(2,2-dimethyl-1,3-dioxolan-4-yl)-2H-chromen-4-yl)morpholine (Preparation 60C, 0.473 M in dichloromethane) (2.47 mL, 1.17 mmol). The reaction mixture was cooled to 0° C., and triethylamine (0.324 mL, 2.34 mmol) was added dropwise over 10 min. The ice-bath was removed, and the resulting cloudy solution was stirred at room temperature for 1.5 h. The reaction mixture was diluted with dichloromethane (50 mL), washed with water (25 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure to afford the crude product as an orange oil. The compound was purified by flash silica gel chromatography using a mixture of ethyl acetate and hexane (5%-12%-20%) to give 7-(2,2-dimethyl-1,3-dioxolan-4-yl)-9b-morpholino-3-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-4,9b-dihydro-3aH-chromeno[3,4-d]isoxazole (0.080 g, 0.140 mmol, 12% yield) as a yellow solid. The product had an HPLC ret. time=3.25 min.−Column: Chromolith SpeedROD 4.6×50 mm (4 min.); Solvent A=10% MeOH, 90% H2O, 0.1% TFA; Solvent B=90% MeOH, 10% H2O, 0.1% TFA. LC/MS M+1=572.1.

Provenance & Evidence