Sulfuric Acid → HCID 67171654, compound

Participants

Reaction Conditions

Reaction Steps

To 6-vinyl-3,4-dihydronaphthalen-1(2H)-one oxime (Intermediate 1, 0.151 g, 0.808 mmol) was added 5 mL of toluene and the contents were concentrated under reduced pressure. The resulting solid was kept under high vacuum for 10 min. The white solid was cooled to 0° C. and lithium diisopropylamide (2.0 M, 0.8 mL, 1.61 mmol) was added drop wise over a period of 3 min. The reaction mixture was stirred at 0° C. for 20 min., then methyl 3-(trifluoromethyl)benzoate (0.087 mL, 0.539 mmol) was added dropwise over a period of 1 min. at 0° C. After 10 min. at 0° C., concentrated sulfuric acid (0.2 mL) was added dropwise at 0° C. and the reaction was stirred for 20 minutes. Water (2 mL) was added and the homogenous solution was heated at 60° C. for ˜2 hr. The reaction mixture was stirred overnight at room temperature. The contents were concentrated under reduced pressure. Next, 5 mL of dioxane was added and the contents were heated at 100° C. for 1.5 hr. The reaction mixture was concentrated under reduced pressure and partitioned between ethyl acetate (20 mL) and sat. aq. sodium bicarbonate (10 mL). The ethyl acetate layer was dried over sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (hexane/ethyl acetate). Fractions corresponding to the product were collected and concentrated to yield 3-(3-(trifluoromethyl)phenyl)-7-vinyl-4,5-dihydronaphtho[1,2-c]isoxazole (0.15 g, 0.439 mmol, 82% yield) as a pale yellow solid. LC/MS M+1=342.

Provenance & Evidence