Cesium carbonate → ethyl 2-(diphenylmethyleneamino)-4-(3-(1-phenyl-5-(trifluoromethyl)-1H-pyrazol-4-yl)-4,5-dihydronaphtho[1,2-c]isoxazol-7-yl)butanoate

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Reaction Steps

A solution of ethyl 2-(diphenylmethyleneamino)acetate (315 mg, 1.178 mmol) in anhydrous dimethylsulfoxide (1 mL) was purged with nitrogen for 10 min before cesium carbonate (192 mg, 0.589 mmol) was added. The mixture was purged with nitrogen for 5 min. and stirred at room temperature for 30 min. Next, 3-(1-phenyl-5-(trifluoromethyl)-1H-pyrazol-4-yl)-7-vinyl-4,5-dihydronaphtho[1,2-c]isoxazole (Preparation 50A, 100 mg, 0.245 mmol) was added, the mixture was purged with nitrogen for 5 min and then stirred at 40° C. for 5 hr. The reaction mixture was cooled, diluted with water (10 mL), and extracted with ethyl acetate (3×5 mL). The ethyl acetate extracts were dried over sodium sulfate and concentrated under reduced pressure. Flash chromatography purification using an ISCO setup (4 g silica gel column, 10→100% ethyl acetate in hexanes) afforded ethyl 2-(diphenylmethyleneamino)-4-(3-(1-phenyl-5-(trifluoromethyl)-1H-pyrazol-4-yl)-4,5-dihydronaphtho[1,2-c]isoxazol-7-yl)butanoate (160 mg, 0.237 mmol, 97% yield) as a glassy solid. LC/MS M+1=675.4.

Provenance & Evidence