Dimethyl Sulfoxide → ethyl 2-(1-oxo-6-vinylphthalazin-2(1H)-yl)acetate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

6-Vinylphthalazine-1(2H)-one (BI27): A solution of 6-bromophthalazine-1(2H)-one (0.25 g, 1.11 mmol), potassium vinyl trifluoroborate (0.446 g, 3.33 mmol) and K2CO3 (0.46 g, 3.33 mmol) in DMSO (2 mL) was degassed with argon for 20 min at ambient temperature. PdCl2(dppf) (0.04 g, 0.055 mmol) was added at ambient temperature, and the reaction mixture was heated to 80° C. for 2 h. The reaction mixture was cooled to ambient temperature and filtered through Celite® bed under vacuum and washed with EtOAc. The reaction mixture was extracted with EtOAc and the combined EtOAc layer dried over Na2SO4 and concentrated under reduced pressure to afford the crude product. The crude compound was purified by column chromatography (SiO2, 100-200 mesh; 50% EtOAc/petroleum ether) to afford the title compound as a brown solid (0.12 g, 63%): 1H NMR (400 MHz, DMSO-d6) δ 13.61 (br, 1H), 8.33 (m, 1H), 8.19 (m, 1H), 8.01 (m, 2H), 6.97 (m, 1H), 6.15 (m, 1H), 5.56 (d, J=10.8 Hz, 1H); ESIMS m/z 172.93 ([M+H]+); IR (thin film) 1748, 1655, 3241 cm−1.

Herkunft & Nachweise