163520-33-0

67428-04-0

163520-33-0

Ethyl 2,2-diphenylcyclopropanecarboxylate (0.97 g, 3.7 mmol) was dissolved in 3.7 mL of trifluoroacetic acid (CF3CO2H). Sodium nitrite (NaNO2, 0.28 g, 4.0 mmol, 1.1 eq.) was added to the solution in batches under controlled reaction temperature not exceeding 40 °C. After addition, the reaction mixture was stirred at room temperature (about 18 °C) for 30 minutes. Subsequently, the reaction mixture was poured into ice water and extracted with ether (2 x 20 mL). The organic phases were combined and washed sequentially with saturated aqueous sodium bicarbonate (NaHCO3) (2 x 20 mL), water (20 mL) and brine (20 mL). The washed organic phase was dried with anhydrous sodium sulfate (Na2SO4). After filtration to remove the desiccant, the organic phase was concentrated under reduced pressure to give a light brown oily crude product. 1H NMR analysis of the crude product showed complete reaction with 100% yield. The crude product was further purified by silica gel column chromatography (Rf: 0.45, eluent: petroleum ether solution of 20% ethyl acetate) to afford ethyl 5,5-diphenyl-4,5-dihydroisoxazole-3-carboxylate (0.958 g, 89% yield) as a white solid.1H NMR (400 MHz, CDCl3): δ 7.41-7.26 (m, 10H), δ 4.34 (q, J = 7.1 Hz, 2H), 3.86 (s, 2H), 1.36 (t, J = 7.1 Hz, 3H). 13C NMR (400 MHz, CDCl3): δ 160.54, 151.09, 142.99, 128.54, 128.02, 125.95, 94.79, 62.15, 46.78 14.12.