Sulfuric Acid → HCID 67171514, compound

Participants

Reaction Conditions

Reaction Steps

To 6-methoxy-3,4-dihydronaphthalen-1(2H)-one oxime (Intermediate 2, 0.483 g, 2.52 mmol) in 4 mL of THF, cooled to 0° C. was added butyllithium (2.5 M, 2.020 mL, 5.05 mmol) dropwise over a period of 3 min. The contents were stirred at 0° C. for 30 min. A solution of methyl 4-propylbenzoate (Preparation 9A, 0.3 g, 1.683 mmol) dissolved in 2 mL of THF was added over a period of 3 min. The pale yellow reaction mixture was allowed to come to room temperature and stirred for 20 min. at room temperature. To the reaction mixture was added 0.5 mL of conc. H2SO4 dropwise over a period of 3 min. at 0° C. The reaction was allowed to come to room temperature over a period of 10 min. and stirred at room temperature for 40 min. The reaction mixture was concentrated under reduced pressure and partitioned between ethyl acetate (25 mL) and water (10 mL). The ethyl acetate layer was washed with sat. aq. sodium bicarbonate (15 mL), dried over sodium sulfate, concentrated and purified by silica gel column chromatography employing hexane/ethyl acetate. Product containing fractions were collected and concentrated to yield 7-methoxy-3-(4-propylphenyl)-4,5-dihydronaphtho[1,2-c]isoxazole (0.355 g, 1.111 mmol, 66.0% yield) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 7.93 (d, J=8.28 Hz, 1H) 7.69 (d, J=8.28 Hz, 2H) 7.30 (d, J=8.28 Hz, 2H) 6.83-6.91 (m, 2H) 3.86 (s, 3H) 2.95-3.06 (m, 4H) 2.61-2.68 (m, 2H) 1.62-1.74 (m, J=7.47, 7.47, 7.47, 7.47, 7.28 Hz, 2H) 0.97 (t, 3H).

Provenance & Evidence