Tetrabutylammonium Fluoride → 1289023-89-7

Participants

Reaction Conditions

Reaction Steps

In a 250 mL round-bottom flask was dissolved (9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one (0.218 g, 0.49 mmol) in tetrahydrofuran (5 mL) to give a colorless solution. After cooling to −15° C. (ice-methanol bath) under nitrogen, TBAF (0.490 mL, 0.490 mmol) was added, and the resulting bright yellow solution was stirred at −15° C. for 1 h. It was quenched with sodium bicarbonate solution and diluted with ethyl acetate. The layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers was washed with brine, dried and concentrated to give a tan oil. Flash column chromatography (25 g silica gel column) up to 100% ethyl acetate/hexane afforded the desired product (112 mg, 62%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.53 (dd, J=4.91, 1.64 Hz, 1H) 7.85 (dd, J=7.68, 1.64 Hz, 1H) 7.34 (dd, J=7.68, 4.91 Hz, 1H) 7.00-7.16 (m, 3H) 5.32 (s, 1H) 4.94-5.04 (m, 1H) 4.48 (dd, J=11.83, 3.02 Hz, 1H) 2.14-2.48 (m, 4H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −138.24-−138.07 (m, 1F) −140.70-−140.50 (m, 1F).

Provenance & Evidence